Machine based on permanent sliding magnets

FIELD: electricity.

SUBSTANCE: invention relates to system of conversion of mechanical energy into electric which, in particular, is suitable for use in the wind energy conversion systems. The system comprises two magnetically separated machines with permanent magnets connected by freely rotating armature on which permanent magnets are located. The first machine is usually a synchronous generator, and the second machine is an asynchronous generator. The synchronous generator has the fixed stator which can be connected to an electric system, such as electric mains. The asynchronous generator has an armature which can be connected to the mechanical drive system, such as, for example, the wind turbine.

EFFECT: technical result consists in creation of the converter of wind energy into electric one with the direct drive and direct connection with mains.

15 cl, 19 dwg

 

AREA of TECHNOLOGY

The present invention relates to excited by permanent magnet machine and the system. In particular, but not exclusively, the invention relates to an asynchronous generator with permanent magnets of a type normally used in wind generators.

Prerequisites FOR the CREATION of INVENTIONS

Asynchronous generator (AG), as he is well known in the art, is a type of electrical generator that electromehanichesky such multiphase induction motor (IM). AG produces electricity when its shaft is rotated faster than the synchronous frequency of the equivalent to HELL. Induction generators are often used in energy conversion systems or wind turbines and some small hydro because of their ability to produce useful energy at extremely varying frequencies of rotation of the rotor. Asynchronous generators are also in General electromehanichesky easier than generators of other types. They are also more durable and do not require brushes or collectors.

However, induction generators are not self-excited, i.e., they require the external supply of electricity to generate a vortex of magnetic flux. External power can be fed from the mains or from the generator, when he start�em to produce energy. Vortex magnetic flux from the stator induces currents in the rotor, which in turn creates a magnetic field. If the rotor rotates slower than the speed of a vortex flow, the machine operates as an induction motor. If the rotor rotates faster, it works as a generator, producing energy at synchronous frequency.

In most of the induction generator magnetizing flux creates a capacitor Bank connected to the machine in case of Autonomous systems. In the case of systems connected to the network, the machine selects the magnetizing current from the network. Asynchronous generators are suitable for wind energy conversion, since in such installations, the rotational speed is always a variable factor.

Known the idea of getting an induction generator with its own excitation permanent magnets (IPM). These generators work on the principle of the availability of additional, freely rotating rotor with permanent magnets (PM) in combination with conventional induction motors are usually located between the induction rotor and the stator. The rotor of the PM in the car creates a thread, thus eliminating the need for magnetizing current, which in turn gives a better power factor for the machine as a whole.

In most commercially available conversion systems wind energy� currently uses a combination of complex gearboxes and asynchronous machines with high rotational speeds. These systems are typically connected directly to the mains, which is possible due to the ability of the AD to the slide, thus allowing a “soft” connection to the network.

A popular alternative to the scheme and system design of wind energy conversion is a synchronous machine low speed permanent magnet (SMPM). Diagram of a typical drive circuit shown in Fig. 1. The drive chain can represent either an asynchronous machine or a synchronous machine. If, for example, missing a gear, a chain drive can be SMPM, and if there is no Converter, it can be an asynchronous machine. SEM can also be based on broadband electronic power Converter to change the voltage level and frequency of the generated energy to allow you to connect the machine directly into the electrical network. Below, the term “power Converter” will refer to broadband electronic power Converter. System such as shown, which does not use the reducer is known as a direct transfer.

On a limited scale (i.e., at the household level) in some countries use several other options, such as asynchronous generator doubly fed (IDP), which is usually the ISP�box in the field of wind turbines, combination SMPM and gearboxes, or induction machines and transformers. As far as known to the applicant, the system of wind turbines currently in use typically consist of electric machines, which operate with a regulator, power Converter, or or with others.

Since most traditional wind turbines typically operate at low speeds, the necessary gear to use them with asynchronous machines with high rotational speeds. Without Converter asynchronous machine can operate only as a device with high rotational speeds due to the large increase of the magnetizing current of induction machines with low rpm fans, directly connected to the network. SEM, on the other hand, can work effectively at low speeds, but cannot be directly electrically connected to the conversion system wind energy.

Gearbox and power converters used in traditional conversion systems of wind energy, are mechanically complex, expensive, requiring large amounts of maintenance pieces of equipment that increase the total cost of the entire system. Gearboxes also contribute significantly to the mass and the loss of the entire system due to, for example heat and noise. Power converters, on the other hand, are complex and expensive, sensitive to electricity systems.

Diagram of a typical IPM shown in Fig. 2. AGPM consists of a conventional stator squirrel cage rotor induction type, and additional, freely rotating rotor with permanent magnets between the stator and the rotor of the asynchronous machine or inside of the rotor (or outside of the stator), as more clearly shown in Fig. 3. When used in a wind turbine the mechanical power of the shaft, which is supplied by the wind turbine rotor in an electric machine is transmitted to squirrel-cage induction rotor, and a rotor with permanent magnets rotates freely and independently on their own shaft. The rotor permanent magnet supplies a magnetic flux in an electric machine and induces voltage in the stator winding, as shown in the diagram of the equivalent electrical circuit in Fig. 4. It is, in principle, reduces the magnetizing current and improves the power factor of the machine. In these generators are typically used standard stator winding and a squirrel cage rotor. However, it was found that there was an effect (moment) of Zubovich harmonic interference fields between the rotor PM and the stator or rotor. This moment causes the locking of the rotor with permanent magnets relative to the core with�lit or the rotor core, that leads to instability of sliding velocity at low frequencies.

Advantages AGPM when applying with wind and other generators are very attractive because you don't need to use the gearbox and power converters for connection to the network. Therefore, such a device is a wind energy Converter with direct drive and direct connection to the network, which is a very attractive idea. But despite these obvious benefits, to the extent known to the applicant, has not yet been installed or tested, none of asynchronous wind generator with permanent magnets. The main reasons for this seems to lie in the complex structure of such machines.

The PURPOSE of the INVENTION

The purpose of the present invention is to propose an asynchronous generator with permanent magnets, which will at least partially solve some of the above problems.

Disclosure of the INVENTION

In accordance with the present invention proposed a system for converting energy into electrical energy, comprising two machines with permanent magnets, with the first of two machines with permanent magnets has a fixed stator, which may be connected to the electrical system, and the second of the two machines with permanent magnets has a rotor that mo�em to be connected with a mechanical system, moreover, the system is characterized in that two machines with permanent magnets connected freely rotating rotor with permanent magnets and magnetically separated from one another.

Other features of the invention provide that machine with permanent magnets are generators, preferably the first machine with permanent magnets is a synchronous generator, and a second machine with permanent magnets is an asynchronous generator, and the rotor of the asynchronous generator is a squirrel cage rotor type.

Other features of the invention provide that the freely rotating rotor includes at least two rotor parts, and each part of the rotor is provided with a sequence of permanent magnets spaced around its perimeter, and has a modular design with parts of the rotor, removable attachable to each other, allowing to operate these machines with permanent magnets together when the parts of the rotor are attached to one another, and separately, when parts of the rotor are uncoupled from one another.

Other features of the invention provide that machine with permanent magnets set end to end in coaxially aligned relative to the common shaft when they work together; that the freely rotating rotor with permanent magnets rotates synchronously with the rotor asynchronous generators�Torah; and that asynchronous generator (27) works on sliding velocity relative to the synchronously rotating rotor with permanent magnets.

Other features of the invention provide that the two sequences of the permanent magnets are mechanically connected to rotate together; the sequence of permanent magnets on the first rotor part will be performed so as to transfer the excitation to the coil fixed to the stator of the synchronous generator; and that the sequence of permanent magnets on the second part of the rotor will be constructed to transmit the excitation coil of the rotor of the asynchronous generator. The first part of the rotor can be removable attached to the second part of the rotor in coaxial alignment.

Other features of the invention provide that the rotor of the induction generator is an asynchronous squirrel-cage rotor type, with a non-overlapping core winding; that asynchronous squirrel-cage rotor type will have a concentrated winding and double layer winding; what system will be put in a wind turbine with rotor blades of a wind turbine attached to the rotor of the asynchronous generator; and that the system would be a system with a direct drive and direct connection to the network.

The invention also proposes a system of energy conversion in electric�tiles, comprising two rotors and the stator, and the first of the two rotors is a squirrel-cage rotor of an asynchronous type, and the second of the two rotors is a freely rotating rotor with permanent magnets, and a freely rotating rotor with permanent magnets includes two coaxially aligned, magnetically separated parts of the rotor, wherein each rotor part has a sequence of permanent magnets spaced around its perimeter, parts of the rotor are arranged so as to allow the sequence of the magnets of the first part of the rotor to transmit the excitation to the coils of the stator and the sequence of the magnets on the second rotor part to transmit the excitation to the coils short-circuited rotor induction type; and also offers wind turbine comprising a system for converting energy into electrical energy, which is described in this document.

BRIEF description of the DRAWINGS

In the drawings:

Fig.1 is an electric circuit diagram of actuator of a conventional wind turbine;

Fig.2 is an electrical schematic of a typical induction generator with permanent magnets (IPM);

Fig.3 is a sectional view traditionally connected asynchronous generator with permanent magnets;

Fig.4 is an equivalent electric circuit of the induction generator with permanent magnets with Fig.3;

Fig.5 - divided asynchronous �generator with permanent magnets in accordance with the invention;

Fig.6 is a sectional view of the divided induction generator with permanent magnets in accordance with the invention;

Fig.7 - dq equivalent circuit steady state and vector diagram (a) AG and (b) synchronous generator (SG);

Fig.8 - types in cross-section and TBE schedules (a) two-layer AG, (b) a single layer of AG, and (c) single-layer SG;

Fig.9 is an equivalent electric circuit divided asynchronous generator with permanent magnets with Fig. 5 and 6;

Fig.10 - three-dimensional graph showing the sensitivity of the torque from Zubovich harmonic interference fields to changes in the pitch of the magnets and the disclosure of the groove in the asynchronous generator in accordance with the invention;

Fig.11 is a two - dimensional graph showing the time from Zubovich harmonic interference field and the step of magnets on the chart of Fig. 10;

Fig.12 is a chart showing the average time against the change in the pitch of the magnets in the system according to the invention;

Fig.13 is a table showing the dimensions of the machine obtained by optimizing the design and minimize the time from Zubovich harmonic interference field;

Fig.14 is a graph showing inductance dq against the current dq system AG according to the invention;

Fig.15 is a graph showing the time from Zubovich harmonic interference field and the uneven torque at full load against the position of the rotor � system of the machine according to the invention;

Fig.16 is a graph showing the time vs percent slide in the machine system according to the invention;

Fig.17 is a chart showing the percentage efficiency of the system of the machine according to the invention for a range of load torques;

Fig.18 is a graph showing the change of reactive power to the load in the machine system according to the invention; and

Fig.19 is a graph showing the rapid current of the SG in terms of the low-voltage network system of the machine according to the invention, which is measured in the laboratory.

DETAILED DESCRIPTION WITH REFERENCE TO the DRAWINGS

A system for converting energy into electrical energy (11), in the present example, also referred to as divided asynchronous generator with permanent magnets (R-APM”), which is shown in Fig. 5 and 6, includes a wind turbine (13), comprising a set of rotor blades (15), cage rotor asynchronous type (17), a rotor (19) with permanent magnets (PM) and connected to the network of the stator (21).

R-AGPM (11) is divided into two electromagnetic PM generator (25 and 27) connected freely rotating modular rotor (19) with permanent magnets. The first generator (25) is a synchronous generator (SG) with its fixed stator (21) is electrically connected to the electrical network. The second generator (27) operates as an asynchronous generator (AG) with its short-circuited p�Thor (17), mechanically coupled to the turbine (13) which runs at slip speed to synchronous rotating the rotor (19) with permanent magnets. The rotor (17) AG is connected with a turbine (13) through mounting plate (29).

The rotor (19) with permanent magnets includes two coaxially fixed shell (31 and 33) of the rotor, each of which has a sequence of permanent magnets (39) spaced around its perimeter on its inner surface. The first shell (31) of the rotor works with CR (25) and second (33) with hypertension (27). This rotor (33) with permanent magnets AG (27) is mounted on the rotor (31) with permanent magnets CR (25), and not overlapping the core winding and the shaft (35) AG (27) mounted on the mounting plate (29); in the case of single layer non-overlapping rotor bar winding core of the coil is short-circuited single-turn rotor can be manufactured separately and then inserted in the grooves of the rotor. It should be understood that the mounting plate (29) can also act as a trailing wire of the rotor (17).

Magnetically separated AGPM thus can be modeled as two separate, unrelated machines (as is also clear from the phase of the equivalent circuit shown in Fig.9). Induced phase voltage in both machines are the result of rotation of the rotor (19) with permanent magnets; in the case of CR (25) voltage�s is induced in the stator (21) at the frequency of the network in the case of AG (27) the voltage induced in an induction rotor (17) in the sliding speed. During operation, the rotational energy of the turbine (13) is mechanically transmitted to the asynchronous rotor (17) and is transmitted magnetically to the rotor (19) with permanent magnets, where it is again magnetically transmitted to the stator (21) SG and then to the network.

Non-overlapping windings are used for CR (25) and hypertension (27). It should be understood that this creates a huge advantage in terms of reducing effects of torque from Zubovich harmonic interference field and the variation of the load torque. In addition, the number of coils less. Low moment from Zubovich harmonic interference field is very important because it affects, among other things, on the stability of a freely rotating rotor (19) with permanent magnets, particularly at low sliding speeds.

It should be immediately obvious that AG (27) can be removed completely, and the wind turbine (13) mounted directly on the mounting plate (37) SG. Generator (11) then it will be just an ordinary wind generator permanent magnet direct drive.

It should be said that the axial length of the rotor (17) AG is less than the axial length of the stator (21) C, both have the same rated power; it is the result of the optimized structure, described below.

And design optimization, and evaluation of technical and operational characteristics of the P-AGPM below, performed on the machine in a stable SOS�oanie and in the reference frame dq, attached to the rotor. The equations of the steady state dq AG (27) and CR (25) are expressed by equations (1) and (2) respectively (as taken facing positive current)

O=IqrRrωslLdrIdr+ωslλmrO=IdrRrωslLqrIqr(1);Vqs=IqsRsωsLdsIds+ωsλmsVds=IdsR sωsLqsIqs,(2)

where ωsl- the speed of the electric slide, equal to ωsltsand ωt- frequency of rotation of the turbine and ωs=2πf - synchronous speed, and where the subscript “r” denotes a rotor (27) AG, and s denotes the stator (21) SG.

The load angle Δ, the angle α of the current and the angle θ=Δ-αsthe power factor of the SG are defined in the vector diagram of Fig.7. General relationship of voltage, current and losses in copper are expressed by equations (3)-(6)

[VqsVds]=2Vrms[cosΔsinΔ];[IqId]=2Irms[cosαsin α].(3)

Vqs2+Vds2=2Vrms2[Vrms=Vgrid];(4)

Iq2+Ids2=2Irms2(5)

andIrms2=Pcu3R.(6)

Pcuin equation (6) is the losses in the copper windings of the rotor or stator. Torque of AG and SG, is expressed by the equation

Tg=34p[(LqLd)I dIq+λmIq],(7)

where the inductance dq is defined as

Lq=λqIq;Ld=λdλmId.(8)

Efficiency AGPM expressed by the equation

η=ηIGηSG,(9)

whereηIG=PgrPt=TgrωsmTgrωtm(10)

and

ηSG=PgsPgr=Tgrωsm(Pecs+Pwfs)PcusTgrωsm(11)

and where the subscript “m” denotes the mechanical rotational frequency. In equation (11) Pwfsand Pecsare respectively the losses to the wind and friction and losses on eddy currents in the core of the SG. Note that Pwfrand PecrAG is practically zero, so that from equation (10) only the remaining losses (copper) is expressed asPcur=Tgrωslm. The moment SG is also expressed from the equation (11)

Tgs=Tgr( Pecs+Pwfs)ωsm.(12)

Pecsin equations (11) and (12) include eddy current losses in the magnets and the yoke PM in SG, which can be significant when using solid magnets and solid Yarm. When operating the generator at a constant speed of Pwfsthe simulation is considered to be constant and is calculated once. Losses in the stator core SG is calculated by the empirical formula using, among other things, data on the flux density in the air gap of the FE analysis. The eddy current losses in the magnets and the yoke of the permanent magnets in SG also define once (after optimization of the structure) from the calculation of the instantaneous losses with FEA. In conclusion, the power consumption and SG reactive power taken from the network or supplied to the network, expressed as

[PgsQgs]=3Vrms Irms[cosθsimθ].(13)

Transverse incisions and FE modeling of non-overlapping windings AGPM and sgpm shown in Fig.8. When the network frequency is 50 Hz, and rated speed of the turbine is 150 rpm and number of poles for SG is p=40; in this case, the same number of poles are also used for hypertension. When p=40 and selecting a combination of 10-12 poles-grooves with a high winding factor of five poles and six slots forming section of the machine in the FE model using negative periodic boundary conditions. For AG and SG use permanent magnets mounted on the surface. For AG were investigated single-layer and two-layer bar winding of the rotor, but for the SG considered only a single-layer winding with pre-made coils. In the case of AG use solid yoke of the rotor as the frequencies of eddy currents are very low. In the case of the SG was seen as laminated and solid, partially segmented rotor yoke.

Here we consider optimal�I design only of a rotor with permanent magnets and the rotor winding AG, shown in Fig.8 (a) and (b). Design optimization AG on 15 kW was performed taking into account the required technical and operational characteristics of the machine, expressed UIGand GIGas

UIG=[PgrωsmηIG]=[15.96kW15.71 rad/s98That 3 %]GIG=[TgrPcurωslm]=[1016Nm276 W0.27 rad/s](14)

where Pgr=15 kW/ηSGin this ηSG=94% and where Singh�ssion rotational speed is 150 rpm. The efficiency of AG was taken very high in the equation (15) to ensure overall efficiency η>92%. Note from equation (14) that the nominal slip is 1,73% and that required less efficiency will increase the nominal glide.

Design optimization of AG was performed by maximizing time on copper losses in the machine. Maximization of time on copper losses at a fixed frequency of rotation is the same as maximizing the efficiency of AG, when the core loss of AG is practically zero. The objective function to be maximized during the optimization, thus, is expressed as

F(X)=TgrPcur(X).(15)

where X - dimensional vector, which includes all sizes of optimized machine. These dimensions include the step of magnets, the pitch of the grooves (in the case of a single-layer winding), the disclosure of groove, groove width, the height of the yokes, the height of the magnets and the diameter of the air gap AG. The diameters of the outer and inner sets of magnets are the same as a SG, and kept constant during optimization. After optimizing the design of the axial length of the set AG reg�irout so, to obtain the required technical and operational characteristics according to equation (14) for nominal losses in the copper. In this new axial length performs further optimization of the design to confirm the optimal design.

The design optimization performed by the optimization algorithm (Powell algorithm), which is integrated with the SE program. At each iteration of the optimization algorithm calls the finite element program to compute the value function from equation (15) for a given X. KE-the program then reorganizes the structure of the elements of the machine according to X and computes the function value by a certain number of nonlinear static FE solutions. This is done as follows:

(i) Irmscalculated by equation (6) for nominal losses in copper from equation (14) with Rrcalculated analytically according to the dimensions of grooves.

(ii) With the known value of Irmsand αr=0 λmrfirst, calculate from one of the SE solution by converting the calculated FE phase flux linkages is proposed in the parameters dq, using the Park transformation. Thus take into account the influence of current q-axis, Iqrat λmr.

(iii) With the known value of Irmsand with a relatively small selected current angle of αrcalculate the initial value for Idrand Iqr.

(iv) If known Tokaji angle of the current solution of the SE is used to calculate λ drand λqrand hence LdrLqraccording to equation (8).

(v) for a known λmr, Irmsand initial values FOR Ldrand Lqrcalculate new values for Idrand Iqrand sliding velocity ϖslcalculated by simultaneously solving equations (1) and (5).

(vi) With the new values of the currents (Idr, Iqrand the new current angle of αrsteps (iv) and (v) are repeated to improve accuracy in the calculation of dq currents; if necessary, you can perform another iteration.

(vii) At known values of currents and inductances in conclusion, compute Tgrfrom equation (7) and F(X) from equation (15) and return to the optimization algorithm. To calculate the function values thus use three or four solutions of the SE.

After obtaining the optimal design method, described above, was further minimized the time AG from Zubovich harmonic interference fields by further adjustments of the pitch of the magnets and disclosure of grooves in AG; these dimensions have the greatest impact on the time from Zubovich harmonic interference fields. Was used the procedure of sensitivity analysis to determine the sensitivity of the torque from Zubovich harmonic interference fields to changes in the pitch of the magnets and the disclosure of grooves. These results are shown in Fig. 10 and were obtained from a large number of static�x TBE solution. From Fig. 10 and Fig. 11 it is clear that there are areas where the time from Zubovich harmonic interference field is almost independent of changes in size and where the time from Zubovich harmonic interference field is very small (less than 1%). Fig. 12 also shows a relatively low sensitivity of the spin moment to change the pitch of the magnets regardless of the disclosure of grooves.

The final dimensions of the machine, found during the optimization of the design and minimize the time from Zubovich harmonic interference fields listed in the table shown in Fig. 13; the optimal scheme of the cross-section of AG shown in Fig.8(a) and (b). Also in the table of Fig.13 shows the nominal technical and operational characteristics of AG. At relatively high efficiency 98.3% of the active mass of the hypertension optimal design is 70% of the active mass of the SG for the optimum design, mainly due to a much better fill factor using rods of the rotor.

Since the system of the wind generator AGPM is an unmanaged, must be received by the decisions of the currents from equations (1) and (2) to simulate AGPM in a stable condition against the load, i.e. against sliding velocity.

For quick results of simulating inductance dq for AG and SG first determined as a function of current. This was accomplished by λm with no load and the dq flux linkages is proposed under load from static FE solutions and subsequent use of equation (8). Inductance dq, calculated thus, for example, AG, shown in Fig. 13. This shows the dramatic effect of saturation and cross-magnetization on the inductance dq (even) for PM machines with installed on the surface.

For simulation of technical and operational characteristics of AG vs. load sliding velocityωsl=ωtωsfrom (1) is taken as a given input parameter. Then figured out Idrand Iqrby simultaneous solution of equation (1) using the initial values for Ldrand Lqrobtained from Fig. 14. With the new values of Idrand Iqrthe values of Ldrand Lqrupdated in the second iteration of Fig. 14, and then calculated the Idrand Iqrby repeated solutions of the equation (1). To improve accuracy you can use to further iteration. When known Idrand Iqrand Ldrand Lqrthe time and efficiency of AG for a given sliding velocity can be determined from equations (7) and (10).

In exactly the same way as for AG, the dq currents (Idsand Iqsfor the SG determined by simultaneous solution of equation (2). In this case, Vrmsand ωsknown, and Δ variable input parameter; Vds and V qsthus, known from the equation (3). At each sliding velocity and computed at each point of AG Δ iteratively increased to increase the time the SG until the desired moment from equation (12). At this value of Δ power and reactive power of the SG is calculated from equation (13).

Some of the results of simulations and measurements of technical performance are shown in Fig. 15-19. Received almost zero percentage point from Zubovich harmonic interference fields, as shown in Fig. 14. Fig. 16 shows the characteristic torque vs. slip AG and SG with squirrel-cage rotor; AG develops rated torque even at less than 2% of the slide and has a limit of handling the torque of 2.0 per unit. Excellent overall efficiency more than 92% was obtained for a wide range of time, as shown in Fig. 17. In addition, the measured efficiency of the SG very good agreement with the calculated results. The change in reactive power of the load, as shown in Fig. 18, when the setting voltage is very interesting - it implies that the generator can be designed so that at low loads feeding reactive power into the network, but at high loads to select the reactive power that exactly matches the way that compensates for the voltage. Or, if the flow of reactive�th power unwanted, you can use a transformer with switchable taps. Fig. 18 shows a leading current SG in low voltage, measured in the laboratory.

It is proved that this new proposed split AGPM with non-overlapping windings for AG and SG gives good results in the sense of efficiency in a wide load range. Saturation and cross-magnetization have a significant impact on the inductance dq and develop the AG and the SG with the surface-mounted permanent magnets. The relatively high measured from the moment Zubovich harmonic interference field of 4.5% for AG attributed to differences in the magnets and production. With not perarivalan core rotor winding rated torque AG obtained at a relatively low sliding velocity is less than 2%; the limit of the overload point of 2.0 per unit projected for this type of winding. It is proved that provides automatic compensation for the change of voltage. In the prototype IPM SG was approximately 60% of the total mass of the generator, and hypertension (with copper bars of the rotor) approximately 40% of the mass. The proposed design AGPM 15 kW solves construction problems usually present in AGPM. This design is particularly well suited for use with single-layer core windings of the rotor AG. This type of design�functions can be used for small and medium wind turbines. The increase in the active mass due to the AG in this case is 67%, but is expected to increase the total mass of the nacelle will be much less.

It should be understood that to increase the electrical stability of the system AGPM of the machine with permanent magnet synchronous generator directly connected to the network, and part of AD (induction generator) connected directly with the rotor blades of the wind turbine. Since these machines are magnetically separated, this implies that the machines HELL and SEE work independently from each other, as each has its own set of permanent magnets. Therefore, energy is transferred between two rotors with permanent magnets, which are mechanically linked.

The action of sliding, typical of HELL, ensures that the stochastic moments induced by the rotor blades of a wind turbine, smoothed out before these moments are transmitted to the rotor of the machine with permanent magnets. This smooth flow of energy allows you to connect the machine with permanent magnets directly to the network.

Complexity specific to traditional mechanical design AGPM, simplified by the present invention by introducing a modular, separate circuitry of the machine. This implies that the machine with permanent magnets and HELL are made separately and vzaimozatmeniya�we. When used how to develop a part of HELL, in fact, much easier to construct than a conventional machine with permanent magnets. Final Assembly is carried out by the installation of the machine HELL in front of the machine with permanent magnets. This modular approach allows you to operate P-AGPM as full AGPM (PM and AG) or as a traditional synchronous generator with PM (no AD).

It should be understood that P-APM of the present invention is therefore AGPM modular, shared mechanical design, which uses specific electrical advantages of electric cars with AD and PM with the independent magnetization, therefore, eliminates the need for heavy gearboxes and expensive power converters.

If the split AGPM (R-IPM) of the present invention compared with the known United AGPM (P-APM), it is obvious that: (i) the amount of PM material used in R-IPM, usually the same as in C-IPM; (ii) the mass of the yoke R-IPM can be more, but it will be small in machines with a large number of poles relative to the total mass; (iii) the number of poles and size of the AG and the SG in the DISTRICT IPM may be different, which is of advantage from the point of view of development; it is impossible for P-AGPM; (iv) in the R-IPM non-overlapping windings can be used in both SG and AG that I�is a huge advantage in reducing the time from Zubovich harmonic interference fields, variation of load torque and a smaller number of coils; low moment from Zubovich harmonic interference field cannot be underestimated, as it affects the start AGPM and stability of the freely rotating rotor with permanent magnets, particularly at low sliding speeds; (v) in R-IPM with AG and SG, installed one after the other, as shown in Fig. 5 and 6, the diameters of the air gap AG and the SG can be brought to maximum to maximize torque.

It should also be understood that either overlapping or non-overlapping windings can be used for AG and SG, but what, in particular, the modular design of the machine in accordance with the invention makes it possible to use non-overlapping windings. Although it is assumed that overlapping windings may in some cases give better results, the use of non-overlapping windings provides significant advantages in cost, which will make the machine more economically attractive.

Therefore, the invention proposes a split of the asynchronous machine with permanent magnets which have magnetic separation of synchronous and asynchronous generators, which implies the presence of two independent electric machines, working together as one cash-generating unit. Mechanical design m�tire of the present invention adheres to a modular, share the approach by setting the asynchronous machine synchronous machine with possibility of their subsequent separation.

As far as known to the inventor, the proposed invention represents the first AGPM with slow speeds and a large number of poles, and also the first AGPM, which will be tested and implemented in the system of wind energy conversion.

By eliminating the need for a gearbox or power Converter of the total cost of the conversion systems of wind energy can be significantly reduced. With fewer active ingredients, the result will be more reliable and durable system. Thus, to use the full potential AGPM, you need a cost-effective solution in the form of a simple design AGPM that proposed in this document.

It should be understood that another advantage of the modular construction system according to the invention is that due to effective independent work of both machines can use any type of configuration.

For example, the HELL with axial flow may be associated with CM with radial flow. In addition, you can also use different topology of the rotor, for example, permanent magnets, is introduced into the outer casing of the rotor (i.e., the concentration of the stream).

The foregoing description prednaznachendlya for example, in the described variant of the implementation can be made of numerous changes and modifications without violating the scope of the invention. In particular, it can be foreseen that synchronous and asynchronous generators can be magnetically separated in several alternative configurations, for example, installed radially, but not coaxial, as mentioned above. The system can include, for example, one machine with overlapping windings and one machine with non-overlapping windings or a machine with radial flow on one side and a machine with axial flow on the other side. In addition, the number of poles on different machines need not be the same. Squirrel-cage rotor part and the second part of the rotor with permanent magnets can also be interchangeable with the second part of the rotor with permanent magnets attached to the turbine, and a short-circuited part, attached to a common rotor with permanent magnets. In fact for both units, you can use any configuration of the machine, if they have the same torque and rated power. It is also envisaged that the second winding machines with permanent magnets can also be short-circuited or be connected to the electrical system. With this type of connection can be made to work with variable speed.

1. System rpvc�ing energy into electrical energy, comprising two machines with permanent magnets, and the first of two machines with permanent magnets has a fixed stator, which may be connected to the electrical system, and the second of the two machines with permanent magnets has a rotor which can be connected to a mechanical system, and wherein the system is characterized in that two machines with permanent magnets have a common freely rotatable rotor in which permanent magnets and magnetically separated from one another.

2. A system for converting energy into electrical energy according to claim 1, characterized in that the machine with permanent magnets are generators.

3. A system for converting energy into electrical energy according to claim 1, characterized in that the freely rotating rotor includes at least first and second parts, and each part of the rotor carries a sequence of permanent magnets spaced around its perimeter.

4. A system for converting energy into electrical energy according to claim 3, characterized in that the freely rotating rotor has a modular design, and the rotor part can be removable attached to each other, this allowing jointly operate the machine with permanent magnets when the rotor part are attached to one another, and separately, when parts of the rotor are uncoupled from one another.

5. The system of energy conversion in electric�Yu according to claim 4, characterized in that the machine with permanent magnets mounted end to end coaxially aligned relative to the common shaft when they work together.

6. A system for converting energy into electrical energy according to claim 3, characterized in that the first machine with permanent magnet synchronous generator is, the second machine with permanent magnets is an asynchronous generator, and the rotor of the asynchronous generator is a squirrel cage rotor.

7. A system for converting energy into electrical energy according to claim 6, characterized in that the freely rotating rotor with permanent magnets rotates synchronously with the rotor of the asynchronous generator, and asynchronous generator works on sliding velocity relative to the synchronously rotating rotor with permanent magnets.

8. A system for converting energy into electrical energy according to claim 6, characterized in that the sequences of the permanent magnets are mechanically connected so as to rotate together, and a sequence of permanent magnets on the first rotor part is made so as to transmit the excitation coil fixed to the stator of the synchronous generator, and a sequence of permanent magnets on the second rotor part is made so as to transmit the excitation coil of the rotor of the asynchronous generator.

9. The system of energy conversion � electric according to claim 4, characterized in that the first part of the rotor can be removable attached to the second part of the rotor in coaxial alignment.

10. A system for converting energy into electrical energy according to claim 6, characterized in that the rotor of the asynchronous generator is a squirrel cage rotor of an asynchronous type, with non-overlapping core of the rotor winding.

11. A system for converting energy into electrical energy according to claim 10, characterized in that squirrel-cage rotor asynchronous type has a concentrated winding and double layer winding.

12. A system for converting energy into electrical energy according to claim 6, which is inserted into a wind turbine with rotor blades of a wind turbine attached to the rotor of the asynchronous generator.

13. A system for converting energy into electrical energy according to claim 1, which is a system with a direct drive and direct connection to the network.

14. A system for converting energy into electrical energy, comprising two rotors and the stator, and the first of the two rotors is a squirrel-cage rotor of an asynchronous type, and the second of the two rotors is a freely rotating rotor with permanent magnets, and a freely rotating rotor with permanent magnets includes two coaxially aligned, magnetically separated parts, and each part of the rotor has a sequence of constant magni�s, posted on its perimeter, and the rotor part are arranged so as to allow the sequence of the magnets of the first part of the rotor to transmit the excitation to the coils of the stator, and the sequence of the magnets on the second rotor part to transmit the excitation on squirrel-cage rotor of an asynchronous type.

15. Wind turbine comprising a system for converting energy into electrical energy according to any one of the preceding paragraphs.



 

Same patents:

FIELD: electricity.

SUBSTANCE: in a non-contact electrical machine the shaft with rotor are made as a cylinder of uniform cross-section with slots for rotating rectifiers. At that diameter of the movable magnet core of the rotary transformer is equal to the rotor diameter while bore diameter of the fixed magnet core of the rotary transformer is equal to the stator bore diameter.

EFFECT: improving reliability and energy efficiency, increasing output power of the non-contact electrical machine.

2 cl, 4 dwg

FIELD: electricity.

SUBSTANCE: heat sinks of the generator-in-built rectifier are made as two aluminium buses (rings) with vent openings to which part diodes are pressed-in, at that a negative bus is placed in a groove of the end shield while a positive bus is placed at the generator frame.

EFFECT: reducing axial dimensions of the generator-in-built rectifier.

2 dwg

FIELD: electricity.

SUBSTANCE: submersible synchronous electric motor contains stator with imbricated core installed in stator casing, the core has radial teeth on inner surface; inside stator there is rotor consisting of m stacked packs divided by central bearings; at outer surface of rotor there are also teeth; between rotor and stator there is a minimum positive allowance and at stator poles there are identical wound inductance coils connected into phases. Each phase consists of two parallel paths, and each path includes in-series diode and coils; diodes in parallel paths are connected in opposition. According to the invention at that each pole of stator has two grooves in which there is a slot wedge made of dielectric material; diodes are collected to rectifier block installed in stator; number of rotor central bearings is m+1, and rotor is fixed in stator due preloaded installation of the bearings.

EFFECT: improving operational reliability and increasing service life of the electric motor, optimising workability of its manufacturing process.

5 cl, 2 dwg

Generator // 2488210

FIELD: electrical engineering.

SUBSTANCE: in the generator containing the front and rear cover with holes there is a stator in the form of a bundle with inducing windings, rotor with excitation source and claw-shaped tips and a rectifier according to this invention in the area of bending of claw-shaped polar tips there are ventilating inserts made as bases with fins and holes located in-between. Due to manufacturing of simple and easy producible ventilating inserts which can be made, for example, of plastic, intensification of heat processes is reached because number, width and height of ventilating fins in connection with slots in the area of bending of claw-shaped tips are compatible with number and square area of standard fans and it allows either reducing a number of standard fan blade or decreasing their width and it some cases it is reasonable to reject installation of a fan itself.

EFFECT: reduction of power consumed for ventilation and thermal and physical characteristics, improvement of operational performance for generator.

3 dwg

FIELD: electricity.

SUBSTANCE: invention is related to electric engineering, in particular, to electric DC machines. The proposed stabilised axial DC generator comprises a body, a pilot exciter, an exciter and the main generator, in which an inner magnetic conductor, a side magnetic conductor with one active end surface and a side magnetic conductor with two active end surfaces are arranged as axial. At the same time, according to this invention, into slots of the side axial magnetic conductor with two active end surfaces at the side of the inner axial magnetic conductor there is an additional winding of excitation exciter, and in the lower part of the generator body there is a voltage controller comprising a metre of voltage deviations, a preliminary amplifier, a unit of power amplification and a power part. The metre of voltage deviations is connected to the output voltage of the generator, and the additional winding of the excitation exciter is connected to a power part of the voltage controller.

EFFECT: expanded area of application of a generator due to stabilisation of output voltage.

2 dwg

FIELD: electricity.

SUBSTANCE: working windings connected in parallel to a load form a closed circuit between each other, which may be supplied from a source of supply. At the same time a part of windings with its group of poles operates in a mode of generation, compensating with its current a decreasing magnetic flow, the other part - in a motor mode, twisting the generator and pulling a counter-electromotive force to the first group. Within a cycle of rotation the sum of electromotive force generation and counter-electromotive forces are equal, but due to active resistance the circuit needs some makeup from a source of supply: an inverter, a microgenerator, an accumulator, or from oscillations of a magnetic flow in stator poles, which is taken by additional windings and after rectification is supplied into an excitation circuit. Besides, the magnetic flow forcedly arises in front of closing poles, if some turns of the winding placed on them are closed at the same time to one of the generator leads. For this purpose a collector may be used, a switchboard operating from a curtain collector or from sensors of rotation or speed of a shaft. At the same time availability of current windings that transfer excitation to poles that are about to generate provides for excitation without a source of supply and a switchboard when reaching a rated mode after receipt of the first current pulse from an accumulator or residual magnetisation. The generator with current excitation may be used for welding, besides, the winding will be phase to any side, both adding and reducing the magnetic flow depending on the welding mode.

EFFECT: simplifying switching and control with simultaneous reduction of a number of switching elements and expansion of generator application area.

4 cl, 4 dwg

FIELD: electricity.

SUBSTANCE: output signal control device comprises an electric generator (100), which comprises a generator winding (103), an excitation winding (104) and a magnetising winding (102). To reduce the output voltage of the generator winding (103) to the specified value, the magnetising current is varied by increasing/decreasing the duty factor of current flow in a switching element (110), connected to the magnetising winding (102). When a unit of zero duty factor detection (2) and a unit of zero duty factor detection (3) identify that the output duty factor with a zero value continues for a preset period of time, a unit of duty factor value increase limitation (4) limits the upper limit value of the duty factor by the specified preset value as the magnetising current increases. Instead of detection of a zero value of the duty factor a unit of duty factor limitation (21a) may used to limit the duty factor with a maximum value determined by voltage of a smoothening capacitor (SC).

EFFECT: invention provides for stabilisation of an output voltage, when a phase-anticipating load is connected to an electric generator.

3 cl, 10 dwg

Electrical machine // 2458446

FIELD: electricity.

SUBSTANCE: in a proposed design of an electric machine comprising a stator and a rotor arranged outside the stator, bearing supports perceiving vertical and horizontal loads, and an electromagnet reducing the load at bearing supports. At the same time, according to this invention, the specified electromagnet is placed inside the stator.

EFFECT: improved power characteristics of an electric machine, its improved weight and dimension characteristics, higher reliability and seismic resistance, significant savings of structural materials.

7 cl, 10 dwg

FIELD: electricity.

SUBSTANCE: device and method of alternate current obtainment with required output frequency from one or more generators with constant or alternating rotation frequency involves changes in generator(s) part saturation depending on required output frequency. Various construction versions of generator, generator stator and windings and circuits using additional saturation of magnetic conductor parts in generator(s) are considered. Rectification methods for obtainment of require output current at constant magnet generators are developed.

EFFECT: high quality of output alternate current as one of the parametres of claimed device.

25 cl, 15 dwg

FIELD: electricity.

SUBSTANCE: invention relates to the field of electric engineering, in particular to single-phased electric generators with electromagnetic excitation executed via contact rings directly from source of DC voltage and may be used in autonomous systems of electric equipment, in automatics and household appliances, on aviation and motor transport, as wind power generators, high-frequency electric generators, synchronous converters of single-phase alternating current frequency, and also in rectification of alternating EMF with the help of uncontrolled and controlled semiconductor valves - as DC generators, contactless exciters of synchronous generators of mobile mini-power stations and low-capacity power stations. Proposed single-phase electric generator comprises stator, anchor core of which is assembled from insulated sheets of electrotechnical steel with high magnetic permeability and has explicit poles with coil single-phase winding of anchor, each coil of which is arranged on according explicit pole of anchor, and rotor comprising inductor with even and odd cores with identical number of explicit poles on each core, even and odd cores of inductor are arranged in the form of packets assembled from insulated sheets of electrotechnical steel with high magnetic permeability, number of inductor cores is at least two, even inductor cores are displaced relative to odd ones in tangential direction by half of pole division of inductor core, inductor cores are placed onto magnetic conductor of inductor, between cores of inductor there are ring-like coils of inductor excitation winding arranged as supplied by DC (rectified) current via brushes and contact rings. At the same time certain ratios must be maintained between number of explicit poles of anchor, number of explicit poles on each inductor core, width of pole arc of explicit anchor poles and width of pole arc of explicit poles of each inductor core.

EFFECT: provides for high power and operational indices of single-phased electric generator.

12 cl, 6 dwg

FIELD: electricity.

SUBSTANCE: in stator slots of three-phase asynchronous welding generator there is laid excitation winding (1), operating windings (2) and (3). Excitation capacitors (4) are connected to excitation winding (1); compounding capacitors (5) and the first rectifier (6) are connected to operating winding (2); the second rectifier (7) and controlled inductor (8) are connected to operating winding (3). Outputs of rectifiers (6) and (7) are connected in parallel to welding electrode (9). Rotor (10) of generator is caged.

EFFECT: increasing welding current and decreasing magnetic loss during on-load operation.

2 dwg

FIELD: electricity.

SUBSTANCE: in slots of three-phase asynchronous welding generator with cage rotor (1) there is laid operating winding (2) and excitation winding (3). To start of operating winding (2) end of excitation winding (3) and rectifier (6) with electrode (7) are connected. To start of excitation winding (3) excitation capacitors (4) are connected. To the end of operating winding (2) compounding capacitors (5) are connected to a triangle connection. Possibility of overvoltage occurrence is stipulated by electric coupling between stator windings. When emergency overvoltage occur overvoltage protection device (8) is actuated; this device is connected to output of rectifier (6), it impacts on commutation device (9) which trips excitation capacitors (4) from excitation winding (3).

EFFECT: increasing welding current and reducing idling losses.

2 dwg

FIELD: electricity.

SUBSTANCE: in an autonomous induction generator a quadripole stator winding is made of 12 coil groups (1-12) and excitation capacitors. The winding of the asynchronous generator in each phase is formed from coil groups (1, 3, 5, 7, 9, 11) in the form of the first dual-beam "star" with outputs (13, 14, 15, 19), to which the excitation capacitors are attached, and the second dual-beam "star" with outputs (13, 16, 17, 18), which are formed by connection of coil groups (2, 4, 6, 8, 10, 12). The output (13) is taken from combined ends (1, 3, 5, 7, 9, 11), connected with starts (2, 4, 6, 8, 10, 12) of coil groups; the output 14 - from combined starts (1,7) of coil groups; the output (15) - from combined starts (3, 9) of coil groups; the output (16) - from combined ends (4,10) of coil groups; the output (17) - from combined ends (6, 12) of coil groups; the output (18) - from combined ends (2, 8) of coil groups; the output (19) - from combined starts (5, 11) of coil groups. Additionally outputs (14, 15, 19) at one side and outputs (16, 17, 18) at the other side are connected to each other by pairs of serially connected compensation capacitors, and general points of connection of these capacitors have outputs for connection of the load to the induction generator.

EFFECT: higher energy efficiency of an induction generator.

6 dwg

FIELD: electrical and electromechanical engineering; various induction machines running as generators.

SUBSTANCE: proposed device for exciting induction generator 1 has group of capacitors 2 connected to phases A, B, C of stator armature winding, as well as group of additional capacitors 3 connected to respective phases A, B, C of stator armature winding through rectifier 4, and unit for regulating output phase voltage of stator armature winding incorporating output voltage sensor 5, threshold voltage unit 6, electronic data conversion and processing unit, and switching unit incorporating control switching members 7. Mentioned electronic data conversion and processing unit has standard clock-pulse generator 8, clock-pulse counter 9, and dc amplifier 10.

EFFECT: reduced setting error of generator output voltage within wide usable load range, enhanced operating reliability of device.

5 cl, 3 dwg

Induction generator // 2255409

FIELD: electrical engineering; specific electrical machines for off-line power supplies.

SUBSTANCE: proposed self-excited induction generator designed for operation under abnormal environmental conditions and in hermetically sealed power-generating units has squirrel-cage rotor and core-shaped stator with Z teeth whose slots receive stator winding, as well as field capacitors; novelty is that stator winding is made in the form of Z bars closed on one end by means of end ring. Generator also has additional magnetic core with slots receiving three-phase winding and conducting bars connected on one end with Z bars of stator winding and on other end they are closed by means of other end ring to form Z-phase winding.

EFFECT: enhanced reliability, reduced mass and size of induction generator.

5 cl, 3 dwg

The invention relates to electrical engineering

The invention relates to the field of electrical engineering and can be used in induction motors, electrical equipment or generators operating in dynamic mode

Stator // 2537791

FIELD: electricity.

SUBSTANCE: invention relates to electrical engineering and wind power, namely to wind power generators with vertical axis of rotation. Stator contains excitation sources, magnetic cores, work coil and bases with fasteners. The magnetic cores are made in form of top and bottom groups. Each group includes angle-bar which horizontal flange looks on the end gap of the rotor element, and vertical flange looks on first end of coil with permanent magnets. The second end of the coil with permanent magnets is connected with common vertical magnetic core.

EFFECT: efficiency improvement due to that not only radial by end gaps are also used.

1 dwg

FIELD: electricity.

SUBSTANCE: in electromagnetic gear containing a housing with mounted stator with multiphase winding coupled to the voltage source as well as the first and second rotors rigidly fixed at the input and output shafts respectively, according to the invention the stator winding is coupled to the voltage source through a regulated frequency converter and placed in grooves of the stator inner surface thus forming poles, while the first rotor is mounted coaxially with stator and fixed rigidly to the input shaft end, is designed as a squirrel cage, which rods are inserted into the rings made from non-magnet material, they have prismatic shape and form teeth of the first rotor, and the second rotor is placed inside the first one and made as a toothed magnetic core with the teeth number z2, equal to z2 = (z1 - p1), where z1 - number of teeth of the first rotor; p1 - number of pole pairs of the stator winding; while the stator, teeth of the first rotor and the second rotor are laminated and made from ferromagnetic thin steel plates.

EFFECT: preserving the possibility of regulation of reduction coefficient at simultaneous providing of design simplification.

1 dwg

FIELD: electricity.

SUBSTANCE: in electromagnetic gear containing a housing with mounted stator with multiphase winding coupled to the voltage source as well as the first and second rotors rigidly fixed at the input and output shafts respectively, according to the invention stator winding is coupled to the voltage source through a regulated frequency converter and placed in grooves of the stator inner surface thus forming poles. The first rotor mounted coaxially with stator and fixed rigidly to the input shaft end is made as a squirrel cage, which rods inserted to rings made of non-magnet material form teeth of this rotor with height equal to a half width of the groove, and the second rotor placed inside the first one is made with grooves at its outer surface and short-circuited winding is placed to them, at that the stator, teeth of the first rotor and teeth of the second rotor are laminated and made of ferromagnetic thin steel plates.

EFFECT: simplifying design with potential regulation of reduction ratio.

FIELD: engines and pumps.

SUBSTANCE: differential gearing with one input and two outputs are used as a gear ratio converter in proposed motor. Gearing input is engaged with motor rotor. One of said outputs is engaged with driven shaft to receive higher torque while second output is engaged with second rotor inductively coupled with motor rotor. Driven shaft rpm is varied by changing the second rotor circuit electric load.

EFFECT: optimum acceleration of the motor, higher efficiency, simplified control.

1 dwg

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