The method of converting mechanical energy from the wind turbine into electrical energy of the battery and system for its implementation
The invention relates to energy, in particular to a stand-alone power supply systems using renewable energy sources (wind energy, water energy of the tides, and so on) with primary engines, the implementation of impact of a possible maximum energy which require changes in speed within wide limits. The technical result consists in minimizing the installed capacity of power equipment, improving the efficiency of the power conversion system and increasing reliability is ensured by the fact that the way to convert EMF of the battery is chosen slightly below the rectified EMF uncontrolled rectifier mode the maximum speed of the wind turbine and the maximum excitation current of the generator, the current control battery charge lead with increasing pulse Converter DC the law of the maximum taken from the wind turbine power, and the excitation current of the generator to regulate by law the maximum efficiency of the system, and for the removal of a possible maximum energy produced by the wind turbine, the rotation speed of the generator is dependent on the wind speed and the maximum system efficiency obespechivaetsya in the corresponding system. 2 N. p. F.-ly, 1 Il.
The invention relates to energy, in particular to a stand-alone power supply systems using renewable energy sources.
There is a method of energy conversion wind turbine in the energy charge of the battery (AB) , namely, that at the first stage of the conversion use a synchronous generator operating in a self-excitation mode, and the second stage energy AC synchronous generator rectifier is converted into energy DC battery power. In such a system work area speedGthe generator is determined by the conditions of self-excitation (G0,7-0,8GN),GN- rated speed of the generator. To accomplish this, you must have the appropriate high - speed wind, but in the area of small and medium wind speeds, when the maximum produced by the wind turbine power significantly exceeds the sum of the capacities of their own needs and mechanically inefficient. A significant drawback of this system is the low quality of the electrical energy produced by it (unstable frequency and RMS voltage).
There is a method of energy conversion wind turbine or other Prime mover in the energy of the battery , consisting in the fact that the excitation power of the synchronous generator is selected from the rectifier or the battery through the regulator excitation current, and the excitation current can be adjusted within wide limits regardless of the speed of rotation of the wind turbine and generator.
This system, along with wind turbines, is widely used in internal combustion engines [3, etc.].
In such a system significantly extends the operating range of wind speeds. Regulation of the current of the battery when this method is carried out by regulating the magnetic flux and EMF generator, which increases the frequency of its rotation.
With this method of energy conversion wind turbine energy battery:
and at the bottom of the working speed range of the generator, when the rectified EMF Edless EMF of the battery, the power of the wind turbine is lost completely; the minimum speed is armature between the generator and transducer), or changing the schema of connection of the windings of the generator (for example, the transition from the triangle at high speeds on a star when small), or by combinations of these funds is large. The introduction of these tools requires a capital expenditure and is accompanied by additional loss of energy, although does not solve the problem completely. In any case, the regulation is likely to be multi-zone (at least two), which complicates the control system. And finally, at the bottom of the range at low speed and power generated by the wind turbine, the generator operates with a maximum nominal excitation current; the flow is attenuated with increasing speed. This is in contradiction with the optimal control on the criterion of minimum losses or maximum efficiency of power conversion system generator - rectifier - regulator device”;
b) is increased installed capacity of the generator. Indeed, if the nominal speed of the generator is chosen to be equal to its maximum value, then the generator must have a supply voltage equal to the ratio of its nominal speed to the minimum speed that provides battery power, at maximum excitation current. And the sub>
In the General case, the power delivered by the generator is determined by the rectified EMF Edthat is greater than the EMF of the battery EABthe value of the voltage drop in the power circuit elements of the system in the first approximation can be assumed equal, and the rectified current Id- charge current IABbattery.
At a minimum frequencyminrotation of the generator condition of charge Ed=EABget supply nominal voltage on the field winding of the generator. When the maximum frequencymaxrotation generator
where- utilization of the generator voltage, the rectified EMF could be
but it reduces to a value of EABthe reduction of the excitation current. Thus, the rated power of the generator is determined by:
wherefor three-phase bridge circuit, while the used power
and utilization enersine Edraises ToCorrbut tells the system the disadvantages mentioned above:
C) reduced efficiency at high operating frequency of the generator is compared with other methods, for example, based on the regulation of Edwith the full magnetic flux.
There is a method of energy conversion wind turbine energy of the battery , which differs from the previous ones by the fact that the excitation current of the generator is kept constant - rated - in the entire frequency range of rotation of the wind turbine and generator, and the control current of the battery is carried out by regulating the output voltage of the rectifier phase method (this method is difficult to implement at a variable frequency and operating voltage), pulse width, or other known methods. The maximum efficiency of electrical machines requires an approximate equality of the constant and variable losses. Therefore, in the area of high working speeds of rotation of the propeller, when its power is proportional to the third degree of velocity, close to the nominal working with nominal magnetic flux would be more economical. However, all the other disadvantages described above in relation to the way the lighting.
This method adopted by us for the prototype.
The proposed method as the method implemented in the prototype contains two stages of power conversion. At first the mechanical energy of the wind turbine, the speed of which varies within wide limits, is converted into electrical energy of alternating current through the synchronous generator, the frequency and RMS voltage which also vary within wide limits; the second electrical energy AC is converted into DC current power of the battery. However, the present invention is devoid of the above disadvantages of the prototype. This is achieved as follows:
a) the EMF of the battery is selected smaller than the rectified EMF uncontrolled rectifier corresponding to the maximum of the excitation current and the maximum speed of the generator, the value of the voltage drop in the power system elements in the regime of maximum impact (active in the resistance of the windings of the stator of the generator, the switching loss of the rectifier voltage caused by the overlapping of its anode current and internal resistance of the battery);
b) introduced the excitation current controller Joannou current boosting the output voltage of the rectifier to the value that provides the battery charge over the entire operating speed range of the wind turbine;
C) charge current of the battery is proportional to this its EMF generated by the wind turbine power, regulate the functions of the wind speed, by law, provide maximum taken from the wind turbine power;
g) the excitation current, generator regulate the frequency function of the voltage on the stator, which is proportional to the rotation speed of the generator, by law, provide maximum efficiency of the system;
d) when the speed of rotation of the wind turbine and generator, close to the maximum working when increasing the current regulator charge is derived from the work, the excitation current of the generator is maintained at a constant close to its nominal value, level, and control the charge current of the battery. When it is increased to the maximum level fixed overcurrent protection, impose mechanical brake, and the installation is removed from the work.
The technical result of the invention is to minimize the installed capacity of power equipment, increasing efficiency and reliability of the system.
Tekhnicheskioi generator rated its value and full use of the generator to flow in all modes while limiting the maximum voltage level, do not exceed the permissible norms PUE limits for this type of generator, and equality maximum power continuous generator to its nominal value. This ensures a minimum installed capacity of the generator, as well as the parameters and dimensions of the rectifier;
b) selection of maximum energy, which is capable of producing wind wheel at a given wind speed. When changing the wind speed taken from the wind turbine power is changed, remaining at the highest possible level;
the optimization criterion of maximum efficiency of the operation mode of the system;
g) the conclusion of the regulatory regime as a system of regulation of excitation and system control charge current of the battery at the maximum wind speed. Thus, increased reliability, and simplified control system state in prabhandam the maximum impact and the possibility of using a simple and reliable protection - current.
Conducted by the applicant's analysis of the prior art, including the search for patent scientific and technical information sources and identify sources that contain information about the equivalents of the claimed invention, has allowed to establish that stenia, and the definition from the list of identified unique prototype as the most similar set of features analogue has identified a set of essential towards perceived by the applicant to the technical result of the distinctive features in the claimed object set forth in the claims.
Therefore, the claimed invention meets the requirement of “novelty” under the current law.
To verify compliance of the claimed invention to the requirement of inventive step, the applicant conducted an additional search of the known solutions in order to identify characteristics that match the distinctive features of the prototype of the characteristics of the claimed invention, the results of which show that the claimed invention is not necessary for the expert in the obvious way from the prior art.
Therefore, the claimed invention meets the requirement of “inventive step”.
The claimed method can be implemented in the system, the scheme of which is shown in the drawing. Here is displayed: 1 - wheel, 2 - multiplier (step-up gear), 3 - a synchronous three-phase generator, 4 - uncontrolled three-phase bridge rectifier, 5 - throttle, 6 - pulse to the first inverter voltage receiving terminals AC), 10 - current control generator excitation, 11 - frequency Converter voltage generator to an analog signal, 12 - functional Converter, 13 - CAP of the excitation current of the generator, 14 - gauge wind speed, 15 - functional Converter that generates job rotation speed of the generator, 16 - CAP charge current battery, 17 - sensor excitation current of the generator.
The system works as follows. Mechanical power generated by the wind turbine 1 via the multiplier 2 is transmitted to the shaft of the synchronous generator 3; stator windings of the generator are connected to the terminals of the alternating current uncontrolled rectifier 4. The DC circuit of the rectifier contains elements increases pulsed constant current regulator: between the positive poles of the rectifier bridge 4 and the battery 8 is connected in series to the inductor 5 and the diode 7, and the cathode of diode 7 is connected with the positive pole of the battery 8, and between the anode of the diode and the combined negative poles of the rectifier bridge and battery included key semiconductor element 6. Battery powered load 9 - consumers energy DC energy Converter permanent botka excitation synchronous generator 3 receives power from the battery 8 through the excitation current controller 10.
For the implementation of the positive properties stated in paragraph 1 of the method of regulating current of the battery is performed over the entire operating range of wind speeds and wind turbine with increasing pulse encoder (items 5, 6, 7): with the closure of the key 6 of the reactor 5 accumulates energy by increasing the current consumed by the circuit from the generator through the rectifier when the break key 6, the energy stored by the inductor 5, is returned to the battery 8. Changing the relative duration of the closure of the key 6, regulate the charge current AB. The diode 7 prevents battery discharge through the closed key 6. It should be noted that the average current is a key element 6 when properly chosen system parameters does not exceed 10-15% from current rectifier bridge 4 mode nominal power of the generator: the relative duration of the closed state of the key, is close to unity at low speed and power generated by the wind turbine is reduced to small values when the speed of the wind turbine, and at a nominal speed value is a key element completely out of work. Thus, parameters, dimensions and cost a key element in the system is small.
For pickup VOZMOZhNOSTI wind. Wind speed is measured by a sensor (anemometer) 14, and functional Converter 15 generates a reference signal at the frequency of the synchronous generator voltage signal proportional to the speed of its rotation.
The control signal is a key element 6 is removed from the output of the automatic control system 16 current battery charge. This signal is generated by comparing the reference signal to the frequency of the stator voltage of the synchronous generator is proportional to the speed of its rotation, with the actual value signal of this frequency, and the reference signal is removed from the output function of the Converter 15, an input connected to the output of the wind speed sensor 14 and which implements the optimal ratio of wind speeds and wind turbine. The optimal ratio of these speeds is that the power generated by the wind turbine, the maximum remains in all operating modes of installation. The signal current value of the frequency of the generator voltage is removed from the sensor frequency 11 - frequency Converter voltage of the synchronous generator to an analog signal.
The charge current in the system is installed in accordance with the optimum ratio of the MSE of the giving of the charge current in all operating modes: each wind speed corresponds to a certain speed wind turbine, when the power they produced, maximum. This correspondence is implemented by functional Converter 15.
This scheme works reliably in a wide range of voltages and currents in the system and at different levels of Edand EABif saved, the ratio of Ed<FAB. This provides the possibility of controlling the excitation current of the generator is not to maintain the ratio of Ed>FABand thereby providing a given current battery charge, as is the analogue of , and, for example, on the criteria of maximum efficiency of the system generator - rectifier pulse - boost regulator”.
The excitation current of the generator is regulated by the regulator 10. The control signal that the controller is removed from the output of the automatic control system 13 of the excitation current. This signal is generated by comparing the reference signal to the excitation current and the actual signal value. The reference signal on the excitation current is removed from the output function of the Converter 12, the input of which is applied the output signal of the inverter 11 frequency voltage of the synchronous generator to an analog signal. The actual value signal current vozbuzhdeno, transmitted through the generator, which, in turn, is determined by the frequency of the voltage on the stator and proportional speed of the generator. The signal frequency of the stator voltage is selected as input for the function of the Converter 12. The basis for calculating the characteristics of the “input-output” functional Converter 12 are pre-calculated or experimentally obtained dependence of the efficiency of the system from the power supplied to the generator shaft with the propeller, and the corresponding speed in function of the excitation current. The maximum value of this function and determine the output signal functional Converter.
Sources taken into account
1. Chapter I. J. the Use of wind energy. - M.: Energoatomizdat, 1983, S. 96, Fig.46.
2. Galkin, M. P., Gorin, A. N. The choice of functional schemes of Autonomous small wind turbines. // Power construction. 1995, No. 3, S. 43.
3. Fesenko, M. N. and the other Theory, design and calculation of road transport equipment. - M.: Mechanical Engineering. 1992, S. 153-156; 178-188, Fig.94-96; 102-104.
4. Mishin, C. F. Complex system of Autonomous power supply of consumers with maximum use of wind energy. // Power construction. 1991, No. 3.
2. System for converting mechanical energy from the wind turbine into electrical energy of the battery containing a wind-wheel, the synchronous generator and the battery to the load, characterized in that it further comprises a multiplier, an uncontrolled rectifier and a current regulator for a synchronous generator, and between the positive poles of the rectifier bridge and the battery is in series connected choke and a diode, and the cathode of the diode connected to the positive pole of the battery, and between the anode of the diode and the combined negative poles of the rectifier bridge and battery included key semiconductor element; a control signal key element is removed from the output of the automatic control system of the current C is Onen generator, proportional to the speed of its rotation, with the actual value signal of this frequency, and the reference signal is removed from the output function of the Converter, an input connected to the output of the wind speed sensor and which implements the optimal ratio of wind speeds and wind turbine, in which the power generated by the wind turbine, the maximum remains in all operating modes of the installation, and the actual value signal of the frequency of the generator voltage is removed from the sensor output frequency of the frequency Converter voltage of the synchronous generator to an analog signal; the control signal excitation current controller of the synchronous generator is removed from the output of the system of automatic regulation of the excitation current and is generated by comparing the reference signal to the excitation current and the signal of its actual value, and the reference signal on the excitation current is removed from the output function of the Converter, the input of which is applied the output signal of the frequency Converter voltage of the synchronous generator to an analog signal.
FIELD: wind power engineering.
SUBSTANCE: invention relates to devices designed for damping hunting of head with windwheel relative to tower of wind plant of horizontal-axial type. Invention is aimed at providing required orientation to wind and preset minimum hunting speed of windwheel. Windwheel hunting damper contains at least one hydraulic shock absorber and device converting rotary motions of windwheel nacelle into reciprocating motion of piston of hydraulic shock absorber. One end of hydraulic shock absorber is fastened on tower, and other end interacts with converting device. The best design version of device is its making in form of zigzag slot with fitted-in roller connected with second end of shock absorber arranged on support-and-slewing unit of nacelle.
EFFECT: provision of universal and reliable design of hunting damper.
3 cl, 2 dwg