Method of power supply in three-phase power mains

FIELD: electricity.

SUBSTANCE: invention is used in electrical engineering. The method consists in following stages: formation of the component of the positive phase sequence system, intended for power supply, formation of the component of the negative phase sequence system, intended for power supply, superposition of the component of the positive phase sequence system and the component of the negative phase sequence system with obtaining of supply current, and supply of such composite current into a three-phase mains.

EFFECT: decrease of non-symmetry in three-phase mains.

12 cl, 5 dwg

 

The present invention relates to a method for supplying unbalanced three-phase current three-phase AC voltage. In addition, the present invention relates to a corresponding device for supplying unbalanced current in three-phase AC voltage, and is equipped with such a device of a wind energy installation.

Electrical energy in large volume is distributed in three-phase AC voltage, in particular, is distributed to consumers by energy producers, such as electric power plant, wind power plant or the like. In particular, consumers are regulated under AC voltage, which has certain characteristics. These include mutual specific frequency and phase between the individual voltages, the amplitude of the voltage of each phase and, finally, also a certain symmetry of the AC voltage. Ideally each phase of the three-phase system, for example, for the European United network, has an effective voltage value equal to 235, frequency, equal to 50.0 Hz and the position of the phases relative to each of the other two phases is 120° or 240°. Compliance with such characteristics is an important requirement, and the deviation is only valid in a small border is. Too much deviation can harm both the stability of the corresponding three-phase AC voltage, and to cause damage to sensitive consumers.

To ensure compliance with the required properties, in particular the symmetry of the three-phase AC voltage, energy producers, in particular electric power plant, carry out supply current in this AC voltage is symmetrical. Large consumers such as factories, equipped with large equipment must ensure that the AC voltage will not be loaded asymmetrically, or will be, but only in very small limits.

In the case of small consumers believe that they collectively essentially load AC voltage only symmetrical.

Yet the situation may arise, when an unbalanced load or under certain conditions, unbalanced supply voltage. The result may be a single network, at least in some areas. In this case, it is desirable or even necessary, depending on the degree of asymmetry, to compensate for the asymmetry in the AC voltage. Powerful generators are often unable to provide such compensation, because they often carry a supply of current through the synchronous gene is ATOR, directly associated with the AC voltage. To separate the phases of the synchronous generator during operation and in case of need it is practically impossible for individual access.

When washing a wind power plant through a full Converter, it would, in principle, it is possible to set, the generation and supply of unbalanced three-phase alternating current, if applicable full Converter has the ability. In this case, each shoulder of the full bridge inverter supplies AC voltage different amount of current.

A different supply voltage may cause unequal load and under certain conditions to too much exercise. If the full Converter is operated to an acceptable limit and it has an asymmetrical current supply, it can mean the excess of the load limit for a single individual shoulder bridge. Accordingly, you should expect accelerated aging of structural elements or even the real problem.

Thus, the present of the invention is to eliminate or reduce at least one of the aforementioned problems. In particular, it must be created the decision for compensation or partial compensation of unbalanced situation in three-phase mains AC is spent voltage, at least one of the aforementioned problems should be prevented or reduced. Preferably should be proposed decision by filing an unbalanced, three-phase AC to AC voltage or prevention of at least one of the aforementioned problems. Should be offered at least one an alternative.

In accordance with the invention offers a way to supply unbalanced three-phase current three-phase AC voltage according to p. 1 of the claims.

The basis of the invention is put well-known fact that an unbalanced, three-phase AC voltage can be represented by a component of the system is a direct sequence of phases and components of the system of reverse phase sequence. Of electrical engineering, in principle, the known method of symmetrical components for the implementation of the simplified analysis of unbalanced faults in the system of the three-phase current ie of three-phase AC system. When this unbalanced system is divided so-called panorami systems direct sequence phase system reverse phase sequence and system zero phase sequence.

The system is a direct sequence of phases, which is also referred to as component C themes direct sequence of phases, has the same direction of traversal of a path as the original system. System reverse phase sequence, which may also be called a system component reverse phase sequence, has the opposite direction of the original system. In fact, it compensates for the deviation of Fedorov from conventional phase shifting at 120°. The system is a direct sequence of phases as such, as well as reverse phase sequence, such as symmetric, each within itself.

System zero phase sequence is called a system in which all fatory have the same direction and the same length. This system zero phase sequence compensates for the likely deviation from zero of the sum of the initial system. However, in this case it turned out that it is often possible to dispense with the system zero phase sequence or, respectively, the components of the zero-phase sequence. In any case, in accordance with one variant of implementation it is proposed to dispense with the system zero phase sequence.

Underlying theory of symmetrical components is still used for the analysis and description of unbalanced three-phase system. So, accordingly, the system of direct phase sequence system and a reverse reproduction is Telenesti phases can be described by magnitude and phase. Using these values possible in-depth analysis.

It is now proposed to create a system of direct sequence phase and reverse phase sequence, and thus established systems of direct and reverse phase sequence to impose obtaining the desired asymmetric system designed to supply current, namely, in particular, unbalanced three-phase alternating current. Thus obtained when applying unbalanced three-phase full current can in this case be submitted to a three-phase AC voltage.

Now you can use three-phase inverter module to form a symmetrical system direct sequence phase. For this three-phase inverter module is, therefore, a standard task, namely, generating a symmetric three-phase alternating current. As this module inverter must only generate a symmetrical three-phase alternating current, and no problem probable unbalanced load or overload of one arm of the bridge.

Another module inverter may establish a system of reverse phase sequence. For this module inverter is only a standard task of generating a symmetrical three-phase alternating current.

The imposition of this system of direct posledovatel the particular phases and system reverse phase sequence, can be carried out simply due to the fact, the corresponding phases are connected each to a single common node. This can be done before or after the output of the throttle.

Both modules of the inverter may have common components. In particular, in the case of the inverter module, using, respectively, an intermediate circuit DC voltage, for two modules of the inverter can be used one common intermediate circuit DC voltage and thus also one common or more common rectifiers for supplying electric power to the intermediate circuit DC voltage.

Example module inverter system direct sequence phase and module of the inverter system for reverse phase sequence is one of the variants of implementation, which is also well suited to explain the main ideas.

According to other variants of implementation proposed to apply more than two modules of the inverter, namely, at least for systems of direct phase sequence or for a system of reverse phase sequence to apply the second module of the inverter. Preferably used several modules of the inverter. To be the generation of unbalanced three-phase alternating current is calculated necessary system direct sequence of phases and the required system reverse posledovatelno and phases. Depending on the amplitude of each of the systems applies appropriate number of inverter modules for the education system direct sequence of phases and the corresponding number of inverter modules to form a system of reverse phase sequence. So, you can use several modules of the inverter having the same dimensions. Then the amplitude of the systems of direct phase sequence or, respectively, the system reverse phase sequence is realized only at the expense of the number of used having the same dimensions of inverter modules. Thanks this can be achieved essentially uniform distribution.

Accordingly, each system is a direct sequence of the phases consists of several partial systems direct sequence phase, and/or reverse phase sequence consists of several partial systems reverse phase sequence. Partial system direct sequence phase or, respectively, partial system reverse phase sequence formed by each module of the inverter and then superimposed. When applying first partial system direct sequence of phases can overlap with the receiving system direct sequence of phases and/or partial system reverse phase sequence, can be superimposed with the teaching system reverse phase sequence, and then together to overlap with getting unbalanced, three-phase alternating current, or partial systems of direct phase sequence and partial system reverse phase sequence all together overlap with obtaining intended for supplying unbalanced, three-phase alternating current.

Preferably, the corresponding phase and amplitude systems direct sequence phase, partial systems direct sequence phases, systems, reverse phase sequence and/or at a known partial systems reverse phase sequence wonder one common Central unit. With this Central device is designed for supplying unbalanced, three-phase alternating current may be calculated by distributed systems direct sequence phase and system reverse phase sequence, which must be provided and created, if necessary, the current may also be distributed in the additional division on partial systems of direct phase sequence and partial system reverse phase sequence. The Central device, which typically receives data regarding the available modules, inverter, can, thus, to realize the full distribution and thereby the JV is to bring to to unbalanced, three-phase alternating current consisted essentially of a set of identical symmetrical three-phase current components. Preferably, the Central unit takes into account the available effective full power available to modules of the inverter. In particular, while supplying the electric energy generated by wind power plants or power, it may be logged in amplitude and, accordingly, may be performed on a current distribution that would be generated.

Using intended for this device, you can also easily manage the symmetric supply current, i.e. not by the invention of the supply current. In this case, you would only need to create a system of direct sequence phase system without reverse phase sequence.

Preferably all partial systems of direct sequence phases have the same phase and/or amplitude and/or all partial systems of reverse phase sequence are, in turn, equal phase and amplitude.

This allows uniform distribution, whereby decrease the likely loads used structural elements and through which can be achieved simplify a calculation, that is, and production.

Preferably proposed method, which is characterized by the fact that the system of direct phase sequence and reverse sequence phases are formed each at least one private module of the inverter and/or one or, respectively, referred to the Central device sets or, respectively, any of the modules of the inverter form a system of direct phase sequence, and what or which of the modules of the inverter form a system of reverse phase sequence.

When creating systems direct sequence phase and reverse phase sequence in each case at least one private module of each inverter module inverter may be limited by the generation of a symmetrical three-phase alternating current. Preferably, the control device sets or, respectively, any of the modules of the inverter form a system of direct phase sequence, and what or which of the modules of the inverter form a system of reverse phase sequence. It also means that the applied inverter modules are not hard-coded for the education system direct sequence of phases or education system reverse phase sequence. On the contrary, depending on the need in each case different is th number of inverter modules can be used for the education system direct sequence phase and also a different number of inverter modules can be used for the education system reverse order phase.

Preferably, depending on the needs may apply one inverter module or several modules of the inverter for different purposes. Accordingly, the inverter module, as an example, may first establish a system of direct sequence phase, and then move on to the education system, reverse phase sequence, or Vice versa.

In accordance with the invention, furthermore, a device for supplying unbalanced three-phase current three-phase AC voltage according to p. 6 claims. Such a device includes at least one first module of the inverter for the education system direct sequence of phases designed to supply current and one second module of the inverter for the education system reverse phase sequence intended for the supply current. Both modules of the inverter are connected in such a way that the system of direct phase sequence is superimposed on the system of reverse phase sequence with obtaining intended for supplying a current, and it is designed to supply the total current. For this purpose, the modules of the inverter, in particular, are properly connected to its output current. It can be provided upstream of the throttle or behind him.

Preferably, the first module of the inverter is ora can be supported by the other modules of the inverter when the education system is a direct sequence of phases, and the second module of the inverter can be supported by the other modules of the inverter when the education system reverse phase sequence.

Preferably, the aforementioned at least one first module inverter and said at least one second module of the inverter are connected through a single common intermediate circuit DC voltage for the formation of the corresponding systems of direct phase sequence or, respectively, the system reverse phase sequence of the constant voltage of this common intermediate circuit DC voltage. Therefore, different modules of the inverter to create the various components of unbalanced three-phase intended for the supply of the current, but use the same common source. In particular, such a common intermediate circuit DC voltage can be powered from one common source, such as, for example, photovoltaic installation or wind energy installation or, respectively, the current produced by the generator of the wind power installation. This also has the advantage that changes in the education systems of direct phase sequence system and reverse phase sequence for the intermediate circuit DC voltage and together with the upstream supply source, there is actually no consequences. So, at least one of the modules of the inverter can also be used in a new way, namely, for the formation of one partial system direct sequence phases instead of one partial system reverse phase sequence, or Vice versa, without any binding effect for the intermediate circuit DC voltage.

In one of the preferred embodiments thus provides that at least one of the at least one first module of the inverter and/or at least one second module of the inverter is designed in order to choose to establish a system of direct phase sequence or part thereof, or system of reverse phase sequence or part of it.

Preferably provides a device which differs from that provided by the Central control device to set the nominal values of the modulus and phase for the formation of the corresponding system of reverse phase sequence or, respectively, the system is a direct sequence of phases and/or to determine which of the first and second inverter modules will be applied to the education system direct sequence phase, and which is for the education system reverse phase sequence.

Thus, a simple and effective way may be prescribed to eliminate the CTB with the overall management, which nevertheless provides various current components, overlapping each other to supply current.

Preferably for connection of inverter modules between themselves and, if necessary, for communication with the Central control device provided by the data bus system. It's a simple way you can exchange data between the individual modules of the inverter and the Central control device, for controlling the individual components and to achieve mutually agreed common mode of the device. This data bus system also preferred when there are many of inverter modules, which are not located in the same building. For example, in the foot of the tower of the wind energy installation can be provided by many of inverter modules, which have one common intermediate circuit DC voltage, in particular an intermediate circuit DC voltage, which is made in the form of so-called busbar. In that case between the individual modules of the inverter is provided a distance, it may be preferable to keep them cool. Also in the case of replacement or maintenance of one of the modules of the inverter, it can detach from the intermediate circuit DC voltage is also disconnected from the data bus, and the replacement module or repaired module is inserted in this place. This allows you to get a modular design and at the same time, the Central management of the total device supply current.

This modular design also allows you to include the same modules of the inverter device supply current, which have different total capacity. These different total capacity, for example, for use in wind power plants of various sizes, can be achieved in a simple way due under an appropriate number of inverter modules.

Preferably proposed wind energy installation, provided with a device for supplying unbalanced three-phase current according to the invention. This wind power plant has, in particular, the rotor comprising a rotor hub and one or more blades of the rotor for converting wind into rotational motion of the rotor. In addition, there is an electric generator, in particular a synchronous generator with an electromagnetic rotor driven just described aerodynamic rotor to generate electric current. This electric current is used after appropriate conversion to supply the AC voltage through the m device for supplying a current. For this purpose, for example, produced by the generator current can stand up and be supplied to the intermediate circuit DC voltage connected to the inverter modules, to perform supply. Preferably the device is located inside or on the tower of a wind power plant, on which are based the above-mentioned rotor and the generator.

A special advantage of the use of wind power installation, provided by the invention a device for supplying unbalanced three-phase current three-phase AC voltage, is that, in particular, for non-Central portions of the AC voltage can be the phenomenon of asymmetry. When using wind power installation it is also possible to install dezentrale, and thereby deliberately to counteract the asymmetry in this off-center section of the network.

In addition, it is also possible selection of electric energy from the AC voltage, with asymmetry, and the transformation in unbalanced three-phase current which counteracts the specified asymmetry. Thus, wind power plant, even when calm, when necessary, can contribute to balancing the asymmetry in the AC voltage.

Present from reenie, in particular, is also provided to meet the requirements established by the regulations, such as technical regulations "Federal Association of the energy and water industry (BDEW), technical requirements for generating units in the network, medium voltage, regulations for the connection and parallel operation of the generating systems in the network, medium voltage, June 2008". Also the invention provides for operation in accordance with the regulations connected with current and, in particular, implementation of the new requirements to the quality of the network such regulations. This applies, in particular, instructions on the system requirements for wind power plants from 10 July 2009

According to one embodiments of the invention the invention a device for supplying unbalanced three-phase current forms a generating unit or, respectively, a portion of the cash-generating device in accordance with the provisions of the Federal Association of energy and water industries (BDEW) for medium voltage.

Below the present invention illustrates more examples of the implementation shown in the figures, which show:

Fig. 1 is a schematic view of the structure of the generating device in accordance with the present invention.

Fig. 2a-2C, the structure of asymmet the ranks of three-phase AC (Fig. 2c) from the system direct sequence phases (Fig. 2a) and reverse phase sequence (Fig. 2b).

Fig. 3 is a schematic view full Converter, which includes several modules of the Converter in accordance with the present invention.

Generating device 1 in accordance with the schematic representation of Fig. 1 includes the phase 2 conversion of energy, which is supplied with electric energy from other forms of energy. So, for example, using wind energy installation wind energy can be transformed through the aerodynamic rotor and the electrical generator into electric current. Between the aerodynamic rotor and the electrical generator may provide for the transfer, which, however, is not considered part of this application. As another example of producing electric energy from other forms of energy can be called a solar cell that can receive electrical energy from the absorbed solar radiation.

To prepare this electrical energy received at site 2 energy conversion, connected to the power grid AC voltage, with a full Converter 4. Essentially all electric energy produced by the phase 2 conversion of energy, channeled through this on the hydrated Converter 4, to supply the AC voltage. Full Converter forms in accordance with the invention, at least one system direct sequence phase and at least one reverse sequence of phases, which overlap the anchor point 6, to then be fed into the network in General, asymmetric total current. In this regard, for illustration depicts a block 8 supply current in the network.

In the case of generating devices, such as generating device 1 containing the full Converter 4, the mode supply current is determined by the Converter of alternating current or, respectively, the full Converter. Type supply current, for example, in relation to the effective/reactive power and phase angle is set by adjusting the power semiconductors contained in the Converter. Unbalanced power supply can be realized due to unbalanced supply voltage. In this case, the supplied current is in accordance with the invention from the system direct sequence phase and reverse phase sequence, which leads to asymmetric total current generating device.

Generating intended for supplying three-phase alternating current is illustrated with the aid of vector diagrams in Fig. 2a-2c. The basis of this explanation, for the sake of argument, p is Lorena structure unbalanced three-phase total current of the system is a direct sequence of phases and system reverse phase sequence. The system is a direct sequence of phases is shown in Fig. 2a. It shows the amplitude and phase of the three currents IL1m, IL2mand IL3m. Circular frequency of the depicted vector system denoted by ω. Circular frequency ω leads to a sequence of phases IL1m, IL2mand IL3m. Phase between the three currents IL1m, IL2mand IL3mare in each case from 120° to 140°. The amplitudes of the three currents IL1m, IL2mand IL3mthe same. Therefore, there is a symmetrical three-phase current.

System reverse phase sequence in accordance with Fig. 2b shows three vectors for the three currents IL1g, IL3gand IL2gthat also have a phase angle equal to 120° or 140°, and which have the same amplitude. Circular frequency for a system of reverse phase sequence, also denoted by ω. System reverse phase sequence, therefore, is also symmetric.

Thus, the generated at least two symmetrical three-phase current.

The overall system is obtained from the overlay system is a direct sequence of phases and system reverse phase sequence. This means that in each case one phase currents of both systems are summarized. Superimposed in this way the system is shown in Fig. 2c. The vectors IL1, IL2and IL3depict three t is ka result asymmetrical, imposed total three-phase current. Accordingly, the vector IL1is obtained by vector addition of the vectors IL1msystem direct sequence of phases in accordance with Fig. 2a and IL1gin accordance with reverse phase sequence, shown in Fig.2b. Accordingly summarized IL2mand IL2gwith the receipt of IL2and also summarized IL3mand IL3gwith the receipt of IL3. This is shown in Fig. 2c. Circular frequency of this asymmetric total system is also denoted by ω. Circular frequency ω for a system of direct sequence of phases in accordance with Fig. 2a, system reverse phase sequence in accordance with Fig. 2b, and the total current in accordance with Fig. 2c are the same.

In Fig. 2c, thus, it is shown that the three-phase unbalanced total current is obtained by superposition of two three-phase symmetrical currents.

To generate depicted in Fig. 2c the total current IL1, IL2and IL3full Converter modular design, in which, for example, for each phase there is an inverter bridge, supplying unbalanced AC would have to allow for asymmetric adjustment of its valves, in particular, the semiconductor relay. But even in the case of full Converter modular design that has multiple modules is nverter, each of which is separately generates three-phase current can be generated asymmetric total current in each inverter module generates asymmetric partial current and all generated asymmetric partial currents are superimposed with obtaining asymmetric total current. In particular, each module of the inverter could generate asymmetric partial current which is in phase and the position of the phases would correspond to the asymmetric total current, but would have a smaller amplitude.

However, in the case of full Converter modular design of the asymmetrical configuration of the valve or, respectively, the semiconductor relay is not necessary. Each module of the Converter can instead draw a symmetrical current, thus the supply of the total current is distributed over the modules of the Converter unevenly. On the contrary, the invention provides job characteristics supply current, which, depending on the desired asymmetry, a certain number of modules of the Converter draws current to clean the system of direct phase sequence, that is, sums up the current system direct sequence phases, i.e. three-phase current in accordance with Fig. 2a, while the other modules down current to clean the system of reverse phase sequence, i.e. down the number of the first current system reverse phase sequence, that is, three-phase current in accordance with Fig. 2b. This distribution is clearly illustrated in Fig. 3. Shows the Converter modules comprise modules to the inverter, as described above, or, respectively, the modules of the Converter can be also called inverter modules.

In Fig. 3 shows a common intermediate circuit Zka constant voltage that is connected to the set of modules M1, M2-Mkand Mk+1-Mnthe Converter. These modules M1-MnConverter form a Converter in the full sense of the Converter 4 in accordance with Fig. 1. The modules M1-MkConverter make up each system direct sequence of phases, that is, the current system is a direct sequence of phases. Other modules Mk+1-MnConverter make up each system reverse phase sequence, that is, the current system reverse phase sequence in accordance with Fig. 2b. Generated thus the currents in the reference point 6 or prior to the overlap and then, as clearly illustrated using block 8, are fed into an AC voltage. Accordingly, the imposition of the anchor point generation device leads to asymmetric total current.

Depending on the control method, however, depending on the chosen implementation of the image is the shadow, the management modules of the Converter is carried out by groups, namely in the so-called group system direct sequence phase and the so-called group system reverse phase sequence, and the amplitude and position of each phase current of the module within a group are identical, or is controlled by each individual module. In this second case, the amplitude and position of the phases of the Converter modules may vary.

In particular, when the control modules of the Converter is carried out by groups and provides Central control device that performs a group setting and, if necessary, also determines the distribution groups may essentially uniform distribution of all intended to supply power for all modules M1-Mnto the extent possible with the available number of modules M1-Mnthe Converter.

The task intended for supplying unbalanced three-phase current can be performed by external inputs, for example, the operator of the AC voltage, or power generating device and/or subject to application of the Central control unit registers the asymmetry in the AC voltage and independently calculates intended for supplying unbalanced AC to PR is to todaythat registered in the network asymmetry.

The preferred way of generating the device is used with a wind energy installation. Preferably the application of the wind energy installation, which can vary in speed and uses a synchronous generator. Synchronous generator generates during operation of the electric current, which leveled and used for the supply of the intermediate circuit DC voltage, such as an intermediate circuit ZkDC voltage shown in Fig. 3. Thanks to the speed control of wind power plants can essentially be isolated from the supply voltage in the electrical network of an alternating voltage. To the intermediate circuit DC voltage is connected multiple inverter modules that can use the energy in the intermediate circuit and, as described, can generate currents system direct sequence phase currents and system reverse phase sequence to blend with obtaining asymmetric total current.

When several modules of the Converter, such as, for example, the modules M1-MkConverter, generate current system direct sequence phase, the current generated in each case one module can be called partial system direct sequence phase Il the partial current system direct sequence phase. Accordingly, when multiple Converter modules, such as modules M1-MkConverter, generate current system reverse phase sequence, current system reverse phase sequence generated by each module of the Converter can be called partial current system reverse phase sequence.

Thus, the present invention can be applied in the management of converters. Preferably applies Converter modular design in which the control modules of the inverter may be carried out individually or in groups. The invention also finds application in the execution of the instructions on connecting to the network, in particular in the framework of the supply of electric energy to the public network, namely the AC voltage of the common areas or, respectively, in the circuit of AC voltage.

The aim is to implement an asymmetric current supply to the generating device (EZE). Such generating unit includes, in particular, also full Converter modular design, through which current supply to the network. The present invention finds application in order to stabilize the network under unbalanced network voltage single-ended power supply.

<> The way in which each module of the Converter performs asymmetrical current supply leads to the unbalanced load on the working tools. For converters optimized for symmetric supply current, unbalanced supply voltage is preferred, maybe even impossible or unacceptable, if you do not make a choice of sizes essential components. In other words, there should be created a completely new concept of the inverter. In the proposed solution, each Converter module separately brings a symmetric shock. For components is provided, therefore, in any case, from the point of view of load, no differences from normal operation, which occurs when current supply is generally symmetrical.

1. Way to supply unbalanced three-phase current three-phase AC voltage, comprising the steps:
the education component of the system is a direct sequence of phases for intended for supplying current
- education component system reverse phase sequence for intended for supplying current
the overlay component system direct sequence phase component and system reverse phase sequence with obtaining intended for the supply current and the waters of such a compound current in three-phase AC voltage.

2. The method according to p. 1, characterized in that the component systems of direct phase sequence consists of several components partial system direct sequence phase, and/or system component reverse phase sequence consists of several components partial system reverse phase sequence.

3. The method according to p. 2, characterized in that the respective phase and amplitude component of the system is a direct sequence of phases, and under certain conditions of partial components of the system direct sequence phase, component systems, reverse phase sequence and/or under certain conditions of partial components of the system reverse phase sequence wonder one common Central unit.

4. The method according to p. 3, characterized in that each of the components of partial systems of direct phase sequence has the same phase and/or the same amplitude, and/or each of the components of the partial system reverse phase sequence has the same phase and/or the same amplitude.

5. The method according to p. 3, characterized in that the component systems of direct phase sequence component and system reverse phase sequence are formed each at least one private module of the inverter and/or one or, respectively, referred to the Central control device which specifies, what or which of the modules of the inverter form a component of the system is a direct sequence of phases and what or which of the modules of the inverter form a component of the system reverse phase sequence.

6. Device for supplying unbalanced three-phase current three-phase AC voltage, comprising:
at least one first module of the inverter for the education component of the system is a direct sequence of phases for intended for supplying current
at least one second module of the inverter for the education component of the system, reverse phase sequence for intended for supplying a current, and
at least one first module of the inverter and at least one second module of the inverter are connected in a way that the component systems of direct phase sequence component and system reverse phase sequence overlap with obtaining intended for the supply of the current.

7. The device according to p. 6, characterized in that the at least one first module of the inverter and at least one second module of the inverter are connected through a single common intermediate circuit DC voltage for the education component of the corresponding system direct sequence phase or component of the system, reverse the consequences of the successive phases of the DC voltage common intermediate circuit DC voltage.

8. The device according to p. 6, characterized in that at least one of the at least one first module of the inverter and/or at least one second module of the inverter is made with the ability to choose to form a component of the system is a direct sequence of phases or part or component of the system reverse phase sequence or part thereof.

9. The device according to p. 6, characterized in that is provided by the Central control device to set the nominal values of the modulus and phase for the formation of the corresponding component system reverse phase sequence or, respectively, the component system is a direct sequence of phases and/or to determine which of the first and second inverter modules used for the education component of the system is a direct sequence of phases, and which is for the education component of the system, reverse phase sequence.

10. The device according to p. 9, wherein the communication modules of the inverter between themselves and, if necessary, for communication with the Central control device provided by the data bus system.

11. Device according to any one of paragraphs.6-10, characterized in that the applied method according to any one of paragraphs.1-5.

12. Wind energy installation, provided with a device according to any one of paragraphs.6-11.



 

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2 dwg

FIELD: electricity.

SUBSTANCE: voltage stabiliser for a power supply system, which stabilises load of active power, comprises the first AC-DC and DC-AC converter to convert between AC power and DC power; and a nickel-metal-hydride battery located between and connected to a high-voltage cable at the DC side of the first AC-DC and DC-AC converter and a low-voltage cable at the DC side of the first AC-DC and DC-AC converter.

EFFECT: reduced mass and dimension parameters of a device.

10 cl, 17 dwg

FIELD: electricity.

SUBSTANCE: balancer is purposed to improve quality of current and voltage balancing in three-phase networks with neutral wire due to self-adjustment of power in case of current change in the neutral wire. The device contains additionally two power stages and automatic control circuit operating as current function of the neutral wire.

EFFECT: improving quality of adjustment due to detuning parameters of the suggested device from current unbalance in the network of 0,38 kV present at the moment.

2 dwg

FIELD: electrical engineering.

SUBSTANCE: power supply device (100) for immediate electric heating of a pipeline system contains basically a three-phase transformer (2), a symmetrisation unit (14), a compensation unit (22). The three-phase transformer (2) is adapted for supporting a single-phase load connected between the first phase (6) and the second phase (8) of the transformer (2). The transformer (2) contains at least one first tap switch (10) on the high-voltage side (12) of the transformer (2). The symmetrisation unit (14) contains the first capacitor means (16) connected between the first phase (6) and the third phase (18) of the transformer and an inductor means (20) connected between the second phase (8) and the third phase (18) of the said transformer (2). The compensation unit (22) contains the second capacitor means (24) connected between the first phase (6) and the second phase (8) of the transformer (2). The first tap switch (10), the first capacitor means (16), the second capacitor means (24) and/or the inductor means (20) are adapted for variation under load.

EFFECT: changing the value of capacity and inductivity of the corresponding capacitive and inductive means under load and optimisation under load on a real time basis.

7 cl, 4 dwg

FIELD: electricity.

SUBSTANCE: three-phase filter balancing device comprises input and output terminals, to which a transformer is connected, having two groups of primary windings connected as serially and oppositely into a "zigzag". A neutral of the first group of primary windings is connected to a zero wire of a supply network and non-linear phase loads. A neutral of the second group of primary windings is an artificial neutral for linear phase loads.

EFFECT: reduced losses of power and its higher quality by separation of zero sequence currents passage paths for these loads.

1 dwg

FIELD: electricity.

SUBSTANCE: level of a specified higher harmonics in a power flux picked by a non-linear load is reduced by extraction of its energy in the form of an equivalent energy of sequence of unipolar periodically repeating width-modulated current pulses, by means of a fully controlled pulse-width-modulation rectifier of a transistor type, which is used to control a modulating signal proportional to the current of the specified higher harmonics. The extracted energy of the higher harmonics is disposed of, by means of its usage for supply to a DC load and accumulation in the form of a DC energy.

EFFECT: reduction of higher harmonic components levels in a supplying power system and increased efficiency of power usage.

1 dwg

FIELD: electric engineering.

SUBSTANCE: application: in electric engineering. The three-leg transformer in three-phase balancing device is comprised of three coils with the first, nearest to leg, and the utmost leg being connected in series and in accord between each other and the total number of windings in coils is equal to the number of windings in the second coil to be opposite connected in zigzag pattern. Free terminals of the first coils are connected to input and output clips, while free terminals of the second coils are integrated in one common zero point to connect phase loads. Semi-conducting a.c. switch is energised between zero terminal of power system and three-phase transformer.

EFFECT: improved reliability and reduced resistance of zero-sequence current.

2 cl, 1 dwg

FIELD: electrical and power engineering.

SUBSTANCE: proposed method intended for measuring current and voltage unbalance level and organizing on-line impact on them in three-phase power systems characterized in low quality of their power characteristics includes measurement of unbalance level with respect to reverse and zero sequence of both line and phase voltages and currents at frequency of each harmonic component. Frequency at which unbalance in analyzed characteristics occurs is found. Results obtained are used to generate control signal by correcting devices.

EFFECT: facilitated procedure.

1 cl, 5 dwg

FIELD: power engineering.

SUBSTANCE: method allows to fully utilize power of traction transformer due to loading its free phase by rectifiers and inverters, one of which is lead by leading phase of contact network, and second one of late phase, which allows to transfer electric energy to contact network, to exclude idling mode, to provide for lower asymmetry on reverse series in power grid 220 (110) kV, and also decreases level of higher harmonics.

EFFECT: higher efficiency, lowered values of quality coefficients of electric energy - asymmetry coefficient of reverse series and values of higher harmonics.

2 dwg

FIELD: electrical engineering.

SUBSTANCE: proposed method intended to enhance power quality characteristics for users subject to negative influence of higher harmonic components includes generation of circuit current higher harmonic components which are in phase opposition to higher harmonics of supply mains using electrical energy of independent power supply.

EFFECT: enhanced electrical energy quality characteristics for power consumers.

1 cl, 3 dwg

FIELD: electrical engineering.

SUBSTANCE: proposed method used to enhance quality characteristics of electrical energy supplied to users susceptible to impact of negative factors of electrical-energy higher harmonic components includes generation of higher harmonic components of current in network which are acting in phase opposition relative to higher harmonics of supply mains.

EFFECT: enhanced quality characteristics of electrical energy supplied to users.

1 cl, 3 dwg

FIELD: electric engineering, possible use in power circuits of various equipment.

SUBSTANCE: three-phased balancing device contains input and output clamps of powering networks. To output clamps, three-phased transformer is connected, primary windings of which are oppositely coupled in a zigzag. In accordance to the invention, between input and output clamps of powering network, first three-phased automatic switch is coupled, having an independent release. Serially with primary windings of three-phased transformer, second three-phased automatic switch is coupled. As zero contact for connection of phase loads, zero contact of primary windings of three-phased transformer, coupled oppositely in a zigzag, is used. Control block is connected serially to independent release, coupled between output clamp of one of the phases and zero contact of powering network, and ensures supply of voltage to independent release and activation of first automatic switch on disabling of second automatic switch.

EFFECT: increased reliability when powered from three-conductor or four-conductor powering network.

3 dwg

FIELD: electric engineering, possible use for powering various equipment.

SUBSTANCE: the balancing three-phased to one-phased transformer of alternating voltage contains input and output contacts, to which a transformer is connected which has primary windings in all three phases and two secondary windings in phases A and C. Primary windings are connected in a "zigzag". Windings of phases A and B, B and C, and also C and A are connected respectively. Secondary windings in phases A and C are coupled oppositely and are connected to output contacts.

EFFECT: reduction of stabilized power and asymmetry of primary currents and voltages.

1 dwg

FIELD: power production.

SUBSTANCE: when non-sinusoidal shape of supply voltage is decreased, electric power is distributed between electronic devices distorting the shape of supply voltage and electronic devices improving the shape of supply voltage during the semi-wave of supply voltage. Device is connected in parallel with consumers introducing distortions of voltage shape. Main voltage is supplied to the device input. Device includes serial connection of phase-shifting chain, control pulse shaper, dc power supply and power switcher, which connects consumers improving the shape of supply voltage to the mains at a certain period of time.

EFFECT: improvement of supply voltage shape and simplification of device design.

2 cl, 4 dwg

FIELD: electrics.

SUBSTANCE: invention concerns current power transmission equipment, particularly high-voltage power transmission. Device includes reactive shunts connected by reactive switches to line, with additional special reactive shunts connected to the line in star network pattern with unearthed neutral conductor.

EFFECT: enhanced shunt compensation of power transmission line in low load mode, stability and reliability in elimination of single-phase short circuits at single-phase reclosing.

1 dwg

FIELD: electrical engineering.

SUBSTANCE: invention relates to electrical engineering and may be used for hardware designing to improve quality and reduce voltage and electric power losses, when such power is transmitted in three-phase four-wire electric networks due to reduction of anharmonicity and asymmetry. Protection device generates 150 Hz frequency current from phase currents. This current is immediately introduced to harmonics 3 current of neutral working wire in opposite phase.

EFFECT: compensating highest current harmonics flowing along neutral conductor.

2 cl, 2 dwg

FIELD: electrical engineering.

SUBSTANCE: invention relates to electrical engineering, and can be used for phase-to-phase distribution of current in magnetically unstable three-phase signals, for example for neutralisation of zero-sequence harmful effects on current feed circuit in three-phase AC-to-DC and DC-to-AC voltage transformers. Proposed device comprises the transformer with its two phase windings connected, each by one output terminal, to zero input terminal, while their other output terminal is connected to appropriate phase input terminal. The transformer comprises two magnetic cores with phase windings connected in series and furnished with central tap. The said windings have their central and extreme free terminals connected to zero and common phase input terminals, respectively. Note here that central output terminal divides the number of turns in each phase windings into unequal parts, smaller ones being connected to opposing phase input terminals.

EFFECT: possibility to use two single-phase transformers with various-shape magnetic cores instead of three-phase transformer.

1 dwg

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