CN1273729C - Megawatt grade wind generator set speed change and distance change control system - Google Patents

Abstract

The invention relates to a wind power generation control system, which is suitable for use in the variable speed and pitch control of megawatt wind turbines. Its structure is composed of a control part, a detection part and a drive. The controller, variable pitch controller and variable speed controller are composed of three parts; the detection part consists of wind wheel rotor, transmission mechanism, doubly-fed generator stator, winding rotor, slip excitation variable frequency power supply and pulse width modulation inverter power supply and other components and sensors Composition; the driving part is composed of servo motors with different functions, and the connection is that the unit components of the detection part are respectively output by sensor signals. The control output is directly connected to the drive template by the control output; the drive template output is connected to servo motors with different functions, and the various parts are coordinated according to the control requirements. It has the advantages of simple structure, stable and reliable operation, and flexible mechanical transmission control.

Description

Variable speed and variable pitch control system for megawatt wind turbines

Technical field

The invention relates to a wind power generation control system, which is suitable for use in variable speed and pitch control of megawatt-level wind turbines.

Background technique

At present, there are mainly two types of grid-connected wind turbines in my country, one is a fixed-pitch stall-type wind turbine; the other is a variable-pitch wind turbine, and both models have developed 600KW prototypes. However, The first type has the disadvantage of low wind capture efficiency. Although the second type has higher wind capture efficiency than the first type, the strong gust impact of the unit makes the wind wheel, transmission system, and hub of the unit Components such as main shaft, gearbox and generator are subject to strong uneven impact and vibration, so the service life is greatly reduced.

Contents of the invention

In order to realize variable speed and constant frequency control of wind power generators, the object of the present invention is to provide a variable speed and variable pitch control system for megawatt-level wind turbines, which utilizes bidirectional converters and four-quadrant frequency converters to achieve the most economical and most efficient output of unit power. effective design solutions.

The technical scheme of the present invention is realized like this: the control system of the present invention is made up of control part, detection part and drive three parts (as shown in Figure 1), and wherein control part is by main controller, is operation controller, distance control The detection part is composed of wind wheel rotor, transmission mechanism, doubly-fed generator stator, doubly-fed generator rotor, slip excitation variable frequency power supply and pulse width modulation inverter power supply component sensor; the driving part is composed of Servo motors with different functions are composed of servo motor devices such as yaw and cooling, hydraulic servo mechanisms and relay control devices. , doubly-fed generator rotor, slip excitation variable frequency power supply and pulse width modulation inverter power supply are respectively output by sensor signals, and the signals are converted into standard signals that can be received by the controller. The digital signal is low level 0V, high level 24V, Analog signal 4-20mA, computer operating status, parameter detection system, sampling and processing the signal, and the processed data are sent to the parameter acquisition system respectively, with input switch status; meteorological power grid parameters; generator operating parameters and system operating status , and then send this parameter to the state controller respectively. The control part is composed of three parts: the main controller, that is, the operation controller, the variable distance controller and the variable speed controller. These control outputs are directly connected to the drive template by the control output; the drive template output is connected to From servo motors with different functions, there are yaw, cooling servo motor devices, hydraulic servo mechanisms, and relay control devices, and all parts are coordinated according to control requirements.

The detailed structure of the three parts of control, detection and drive is as follows:

The control part is:

1. Main controller

The main controller is the core controller of the control system. The main controller (as shown in Figure 2) is completed by the S7-300 series programmable controller. All output and input signals of the system are composed of five interface circuits with different functions, namely Control strobe circuit, input photoelectric isolation circuit, Hall power sensor interface circuit, switch input isolation circuit, variable speed controller interface circuit and output control drive circuit, among them, the temperature of other components such as engine room temperature and hydraulic oil temperature are selected by control Through the circuit input to the programmable controller; low-speed shaft speed; high-speed shaft speed, wind speed, wind direction, forward and reverse counters, variable pitch angle input and output signals are input to the programmable controller through the input photoelectric isolation circuit; stator a-phase voltage, Stator b-phase voltage and rotor a, b, c phase voltage and phase current signal output are input to the programmable controller through the interface circuit of Hall power sensor; vibration signal, motor overload, left and right torsion limit, vibration and overspeed switch, gate Blade wear, pressure switch 1, 2, 3, 4, maintenance, and emergency stop signals are all input to the programmable controller through the switch input isolation circuit; the output of the variable speed controller interface circuit is connected to the stator grid connection, rotor excitation and inverter The input terminals of grid connection, speed control, power control, main circuit cooling, and controller heating, and the output terminals of the output control drive circuit are respectively connected with control box heating, gear oil heating, heat dissipation, hydraulic oil heating, motor dehumidification, and yaw gate valve. , hydraulic oil pump, hydraulic valve position 1, 2, 3, yaw motor 1, 2, cabin fan, mechanical gate motor, variable pitch proportional valve, variable pitch control, control box cooling input end, variable speed constant frequency wind turbine main control program The flow chart (shown in Figure 3), the dotted line in the upper left corner is the operation controller, the controller first completes the test and record of the weather, power grid, wind turbine and inverter status parameters required for system monitoring, and the process starts-grid-intelligence Control-off-grid-safety shutdown is the main line, respectively carry out start-up preparation, yaw adjustment, fault handling and intelligent optimization parameter calculation, speed and power control setting and system operation management according to the requirements, and the dotted line on the right is the pitch controller , it is given the control method and pitch position/speed given by the intelligent control module, and the target power adjustment of the pitch angle is realized by the hydraulic system and the pitch change mechanism. The dotted line in the lower left corner is the variable speed controller, which is connected with the main controller Form a master-slave control system, the master controller is managed by it, and the variable speed controller becomes a slave controller, and under the management of the master controller, it independently performs its variable speed operation management; firstly, detect the parameters of the generator stator rotor and the power grid (I, U, N, τ, O, cosφ), adjust generator power factor, unit power optimization control, wind rotor speed optimization control, constant frequency constant voltage control and PWM modulation output control, generator stator/rotor parallel The network is controlled by the variable speed controller, etc. The intelligent control module in the main controller is also given for the power and speed optimization control calculation target of the unit. When the main control is out of control, the variable speed and variable distance control, system protection control, Safe shutdown of the unit.

2. Pitch controller

The variable pitch controller (abbreviated as the variable pitch controller) is composed of the windward position detection sensor of the blade, the pitch adjustment speed detection sensor, the position regulator, the speed regulator, the pitch variable actuator and the hydraulic servo mechanism, (by Fig. 3 As shown) the variable pitch controller adjusts the position and speed of the pitch mechanism according to the control target given by the intelligent control module, and completes the pitch control of the wind turbine. The pitch control is to keep the output of the wind turbine above the rated wind speed Constant rated power, and the power control of adjusting the windward angle of the blade by rotating the blade along its longitudinal axis. The adjustment method is divided into three stages: the first stage is the start-up stage. The pitch angle of the blades, the first step is to adjust the pitch angle to about 28°; when the speed reaches 1/2 of the rated speed, then adjust to the angle of the flat blade 0° until the wind turbine reaches the rated speed and is connected to the grid for power generation. The first stage is: when the wind speed is lower than the rated wind speed value, that is, when the output power is lower than the rated power, the blade pitch angle remains unchanged at the open and flat position. The third stage is: when the wind speed is greater than the rated wind speed value, and the power reaches the rated power. Finally, the pitch control system is put into operation. The key to the adjustment is the rated power at the rated wind speed. The pitch adjustment is constantly carried out with the change of the wind speed. In the present invention, the variable pitch control and the variable speed control are combined to achieve the purpose of power optimization control.

3. Variable speed controller

The variable speed controller is the invention key point of the present invention, and the variable speed controller is roughly divided into three parts: the variable speed control core controller hardware, the variable speed control principle realization software, the variable speed controller main circuit, the variable speed control adopts the vector control technology, and the slip The frequency, phase, and amplitude of the variable frequency power supply are adjusted to achieve the purpose of adjusting the excitation current of the generator, and realize the control of the wind rotor rotor to be adjusted according to the control target. There are three methods, ① doubly-fed generator synchronous machine grid-connected adjustment method, ② the forced grid-connected method whose speed exceeds the range of grid-connected speed, as the wind speed continues to increase, it is judged whether the unit meets the rotor power generation conditions, and the rotor power generation in this system The conditions are that the wind speed exceeds the rated power point, the four-quadrant converter works stably, and the speed exceeds the synchronous point; the rotor is fed back to the grid by the pulse width modulation inverter on the grid side, and the system's constant frequency and constant voltage, speed and The power optimization control is realized by adjusting the current amplitude, phase and frequency of the slip excitation frequency converter on the motor side. The control method can be given by the main control, or the variable speed controller can calculate the optimal given value by itself, as shown in Figure 7. The principle block diagram of variable speed and variable pitch control. In the variable speed control, the four-quadrant variable frequency power supply is the key to the controller. It is the focus of system safety protection. When it (the main circuit) fails, the relay logic control circuit realizes the off-grid shutdown protection of the unit.

4. Constant frequency control

The present invention adopts a doubly-fed wire-wound induction generator, the stator winding of which is directly connected to the power grid, and the rotor winding is supplied with three-phase low-frequency excitation current by a low-frequency power supply with adjustable frequency and voltage. When the rotor winding passes through the three-phase low-frequency current, A low-speed rotating magnetic field is formed in the rotor, and the rotating speed (n ₂ ) of this magnetic field is superimposed on the rotating speed of the rotor (n _r ), making it equal to the synchronous rotating speed (n ₁ ) of the stator, that is, n _r ±n ₂ = n ₁ ,

Therefore, the corresponding power frequency voltage is induced in the stator winding of the generator. When the wind speed changes, the rotational speed n _r changes accordingly. When n _r changes, the frequency of the rotor current and the speed n ₂ of the rotating magnetic field change accordingly, so as to Compensate for changes in motor speed and keep the output frequency constant. The low-frequency power supply used in the system is a power conversion device that converts one frequency into another lower frequency, that is, the slip excitation frequency converter of the system. In order to obtain better The output voltage and current waveform, the output frequency does not exceed one-third of the input frequency, since the slip excitation frequency converter is in the rotor circuit (excitation circuit) of the generator, its capacity does not exceed 36% of the rated power of the generator. The generators in the system can operate super-synchronously (the direction of the rotor’s rotating magnetic field is opposite to that of the wind rotor, and n ₂ is negative), or sub-synchronously (the direction of the rotor’s rotating magnetic field is the same as that of the wind rotor, and n ₂ is positive), In the former case, in addition to the stator feeding power to the grid, the rotor also feeds part of the power to the grid; in the latter case, while the stator feeds power to the grid, part of the power needs to be fed to the rotor.

5. The principle of the main circuit of the variable speed controller

The main circuit of the variable speed controller (shown in Figure 6) consists of a slip excitation frequency converter, a pulse width modulation inverter, a DC bus, K1, K2, K3 control contactors, and a filter, among which the slip excitation frequency converter , DC bus and pulse width modulation inverter constitute the main circuit of the four-quadrant converter. The topological structure of the circuits on both sides of the DC bus in the main circuit is basically the same. It is composed of IGBT inverter/rectifier bridge and drive circuit. The bus capacitors and resistors are connected. The bus voltage depends on the voltage generated by the generator stator and rotor. The voltage generated by the generator rotor is lower than the voltage of the stator. However, when the rotor feeds power to the grid, the circuit must use chopper boost to achieve inverter grid connection. This circuit connects inductors, capacitors L1, L2, L3, C1, C2, and C3 at the outlet of the pulse width modulation inverter on the grid side, and combines with IGBT pulse width modulation to realize low-voltage power generation of the rotor and grid-connected energy feedback. At the same time, these Capacitors and inductors are also part of the sine wave filter.

6. Circuit principle of variable speed control core controller

(As shown in Figure 8) the main controller is composed of two parts, the CPU board and the peripheral interface circuit board. The microprocessor chip of the main CPU board is TMS320F240, and 64K16-bit program memory and 64K16-bit data memory are expanded on the bus, providing 12 channels PMW output, 2-way 10-bit channel A/D output, 3 16-bit general-purpose timer outputs, the system has SPI and general-purpose RS-232 interface, 16-way A/D input interface, an extended MP7680JE interface, with 4-way 12-bit D/A output, expand two SR128KX8R fast flash memories, so that the system has 128*16-bit SRAM program and digital memory, and there are four 74ACT245 bus drivers on the bus. These device circuits constitute a DSP high-performance digital micro-processing system. The interface circuit board is composed of four parts, digital signal input processing, isolation circuit; analog signal output/input gating, amplification, isolation circuit; PWM wave output stabilization isolation circuit; switch signal output amplification isolation circuit.

In the present invention, the advantages of variable speed and constant frequency technology are absorbed, so that the wind turbine has the following characteristics: the double-fed generator vector control technology is adopted, and by adjusting the rotor excitation current, the speed optimization and variable speed operation of the wind rotor rotor can be realized. At the same time, dual The active power regulation of feeder generation makes the double-feeder AC power generation system have all the characteristics of synchronous generators connected to the grid. The system can not only transmit electric energy to the grid, but also adjust the power of the generator by controlling the phase relationship between output current and voltage. factor, transmit or absorb reactive power to the grid, perform reactive power compensation for long-distance wind power transmission lines, and improve the quality of wind power grid-connected power supply.

Combination of doubly-fed generator rotor excitation control technology and bidirectional four-quadrant operation frequency conversion technology realizes the flexible connection between the wind turbine rotor and the generator under the variable speed and constant frequency operation state of the wind turbine, so as to reduce the impulse force caused by the peak load on the blades and the transmission mechanism , to achieve the multiple effects of improving the power generation efficiency of the unit, enhancing the protection function and prolonging the service life of the system.

The combination of variable pitch target power tracking and variable speed adjustment ensures stable rated power output above the rated wind speed point. Under the rated wind speed, it maintains the best tip speed ratio operation state, improves the efficiency of capturing wind energy, and makes the system operate in the full wind speed range. to obtain the optimum energy output within.

Using advanced computer control technology and implementing self-learning operation control strategy, while obtaining the best operating characteristics of the unit itself, it can ensure that the system optimizes the performance indicators of the control system in real time, so that the unit can maintain the optimal operating state and feed high-quality electric energy to the grid.

Description of drawings

Figure 1 is a structural block diagram of the variable speed and variable pitch control system of a megawatt wind turbine;

Figure 2 is a block diagram of the main controller of the variable speed and variable pitch control system for megawatt wind turbines;

Fig. 3 is the program flow chart of the main controller of the variable-speed and constant-frequency wind turbine of the variable-speed and variable-pitch control system of the megawatt-scale wind turbine;

Figure 4 is a block diagram of the variable speed and variable pitch control system of the megawatt wind turbine;

Fig. 5 is a variable pitch and variable speed control flow chart of the variable speed and pitch variable control system for megawatt-scale wind turbines;

Fig. 6 is a schematic diagram of the main circuit of the variable speed and variable pitch control system of the megawatt wind turbine;

Fig. 7 is a schematic block diagram of the variable speed and variable distance control system for megawatt-scale wind turbines;

Figure 8 is an electrical schematic diagram of the variable speed control core controller of the variable speed and variable pitch control system for megawatt-scale wind turbines.

Detailed ways

How this system works:

The control principle of variable speed and variable pitch is shown in the block diagram of the control principle in Figure 7. The system control takes tracking the change of wind speed as the adjustment quantity, and takes the optimization of the wind rotor speed, output power and system safe and stable operation as the control objectives, forming three control system adjustments. Main line: (1) The goal is to optimize the control of the wind rotor speed to form a closed-loop control link: the target speed is given by the intelligent module and subtracted from the actual speed, and the deviation value enters the block diagram 5-block diagram 9-block diagram 11 for vector control Coordinate transformation 17, and then enter the slip excitation Irq current closed-loop adjustment, the regulator 5 performs proportional differential adjustment on the excitation current signal Irq, the signal output is converted into a voltage signal through the resistance, and finally superimposed into a PWM modulated output wave, which is output by the rotor current The detection enters the coordinate transformation 17, and the current is sent to the comparison node B5 to form a closed-loop negative feedback adjustment control of the excitation current. The change of the excitation current causes a change in the speed, and enters the comparison node B1 through the speed test link to form a closed-loop control of the speed; Power optimization control is a 2-way closed-loop control formed with the goal. Power optimization includes the adjustment of active power and power factor (the invention is for indirect adjustment of reactive power). The intelligent control module provides a given active power and the actual useful power After the subtraction, the rotational speed deviation is obtained, which enters the regulator 2, and the torque component of the other way through the divider 6 enters the adder to be summed and multiplied by the proportional factor Km ₂ , and then enters the adder 10, and after coordinate transformation, it is used as the excitation The amplitude variation of the current is adjusted by the closed-loop feedback adjustment system composed of the regulator 5. The regulator 6 regulates the excitation current Ird component, and Irq and Ird complete the modulation output of the PWM wave together with the regulation loop.

(3) According to the power characteristics and wind speed characteristics of the system, determine the pitch position target and the pitch speed adjustment target setting, and subtract the actual pitch position and speed to obtain the deviation signal into the The regulator 30 and the PID regulator 36 output adjustment signals to drive hydraulic actuators respectively, and the position detection signal of the pitch is used as a feedback signal to complete the target tracking control of the pitch angle.

Claims (7)

1, a kind of megawatt-level wind unit speed change, displacement control system, it is characterized in that this system by control, detect and drive three parts and form, wherein control section is operation controller (10), feather controller (11) and variable-speed controller (12) three parts and is formed by master controller; The test section is made up of unit wind wheeling rotor (1), driving mechanism (2), double-fed generator rotor (3), double-fed generator stator (4), slip excitation variable-frequency power sources (6) and pulsewidth modulation inverter (7) parts; Drive part is by the actuating motor of control output drive template and difference in functionality, driftage is arranged, cooling actuating motor device (14), hydraulic servomechanism (15) and relay control device (16) are formed, the connection of above-mentioned each parts of control system is unit wind wheeling rotors (1) of test section, driving mechanism (2), double-fed generator rotor (3), double-fed generator stator (4), slip excitation variable-frequency power sources (6) and pulsewidth modulation inverter (7), export with sensor signal respectively, wherein signal conversion becomes the receivable standard signal of controller, digital signal low level 0V, high level 24V, analogue signal 4-20mA, computer operation condition, parameter detecting system (5) carries out sampling processing to this signal, data after the processing are sent into the parameter acquisition system more respectively, and the input switch state is arranged, meteorological electrical network parameter, generator operation parameter and system running state (9); Again these data are sent into operation controller respectively, the output of three controllers (10), (11), (12) directly is connected to control output drive template (13); Drive template output is connected to the actuating motor of drive part difference in functionality, and driftage, cooling actuating motor device (14), hydraulic servomechanism (15) and relay control device (16) are arranged.

2, by the described control system of claim 1, it is characterized in that master controller is the core controller of control system, the core of controller comprises that the interface circuit of difference in functionality promptly controls gating circuit, the input photoelectric isolating circuit, Hall electric weight sensing interface circuit, the switching value input isolation circuit, variable-speed controller interface circuit and output controlling and driving circuit, wherein, cabin temperature, hydraulic fluid temperature and gear case oil temperature, the motor coolant temperature, the control box temperature, the front main bearing temperature, the rear min bearing temperature, the rotor temperature, the motor stator temperature, ambient temperature, the motor bearings temperature, microcomputer oven temperature, degree, the temperature signal output of IGBT case is input to programmable controller by the control gating circuit; The lower velocity shaft rotating speed; High speed shaft rotating speed, wind speed, wind direction, just, inverse time counter, displacement angle input/output signal be input to programmable controller by the input photoelectric isolating circuit; Stator a phase voltage, stator b phase voltage and rotor a, b, c phase voltage, phase current signal output are input to programmable controller by Hall electrical quantity sensor interface circuit; Vibration signal, motor overload and the left and right limit, vibration and over speed switch, brake lining wearing and tearing, pressure switch one, two, three, four and maintenance, the emergent stop signal turned round all are input to programmable controller by the switching value input isolation circuit; Variable-speed controller interface circuit output is connected to that stator is incorporated into the power networks, rotor-exciting and inverter is incorporated into the power networks, each input end is heated in rotating speed control, power control, main circuit cooling, controller, and output controlling and driving circuit output end is connected to control box heating, gear oil heating, heat radiation, hydraulic oil heating, motor dehumidifying, driftage gate valve, hydraulic-pressure pump, hydraulic pressure valve position one, two, three, yaw motor one, two, cabin fan, mechanical brake motor, displacement Proportional valve, displacement control, control box respectively and cools off input end.

3, by the described control system of claim 1, it is characterized in that the feather controller is by blade upwind position detecting sensor, the pitched speed detection sensor, position regulator, speed regulator, feather actuator and hydraulic servomechanism are formed, the feather controller is pressed the given control target of intelligent control module, regulate the position and the speed of pulp distance varying mechanism respectively, finish the feather control of wind-powered electricity generation unit, feather control is to make the wind-powered electricity generation unit keep the constant rated power of the above output of rated wind speed, regulate the facing the wind power control at angle of blade and rotate along its vertical axle center by blade, its regulative mode is divided into three phases: the phase I is a start-up phase, when wind energy conversion system reaches operating conditions, calculate given blade pitch angle, first step pitch angle is adjusted to about 28 °; When rotating speed reaches 1/2 rated speed, be adjusted to out 0 ° of the angle of flat oar again, reach rated speed up to wind energy conversion system and generate electricity by way of merging two or more grid systems; Second stage is: when wind speed was lower than the rated wind speed value, when promptly output power was less than rated power, the blade pitch angle remained on out flat oar invariant position; Phase III is: when wind speed during greater than the rated wind speed value, and power reach specified after, the feather regulating system puts into operation.

4, by the described control system of claim 1, it is characterized in that variable-speed controller is divided into three parts: speed Control core controller hardware, the speed Control principle realizes software, the variable-speed controller main circuit, speed Control is to adopt vector control technology, frequency to the slip variable-frequency power sources, phase place, amplitude is regulated, reach generator and carry out field current adjusting purpose, realize the control that wind wheeling rotor is regulated by control target, control is with generating unit speed and power optimization control, stator and rotor generate electricity by way of merging two or more grid systems, adopt two kinds of ways, the a double-fed generator synchronizer regulating method that is incorporated into the power networks, the b rotating speed surpasses the pressure and the net mode of the scope formula of the rotating speed that is incorporated into the power networks, along with wind speed constantly increases, judging whether unit satisfies the rotor power generation conditions, is that wind speed is crossed the rated power point in native system rotor power generation conditions, four quadrant convertor working stability and rotating speed are crossed synchronous points and are satisfied simultaneously; Realize that by the grid side pulse width modulation inverter rotor send to the electrical network feedback, the constant frequency and constant voltage of system, rotating speed and power optimization control are realized by the current amplitude of turning poor excitation converter, phase place and the frequency of motor side, control mode can adopt the given mode of master control, also variable speed control calculation optimization setting value voluntarily.

5, by the described control system of claim 1, it is characterized in that constant frequency control employing double-fed winding-type influence generator, its staor winding directly inserts electrical network, the rotor winding is supplied with the three phase low frequency field current by a frequency, low-frequency power that voltage is adjustable, when the rotor winding passes through the three phase low frequency electric current, in rotor, form a low speed rotation magnetic field, the rotational speed (n in this magnetic field ₂) with the wind speed round (n of rotor _r) superimposed, make it equal the synchronous speed (n of stator ₁), n _r± n ₂=n ₁, induce corresponding power-frequency voltage in the generator unit stator winding, when wind speed changes, rotating speed (n _r) change, at (n. thereupon _r) when changing, the speed (n of the frequency of corresponding change rotor current and rotating magnetic field ₂), with the small electromotor change in rotational speed, keep output frequency invariable, the low-frequency power that is adopted in the system is that a kind of frequency translation is become the power-converting device of another kind of lower frequency is the slip excitation converter of system, in order to obtain output voltage and current waveform, output frequency is no more than 1/3rd of incoming frequency, because the slip excitation converter is in the rotor loop of generator, its capacity is no more than 36% of generator rating power, generator in the native system can supersynchronously move, and also can subsynchronously move, in the previous case, except that stator to electrical network is presented electric power, rotor is also presented a part of electric power to electrical network; Under latter event, then at stator when electrical network is presented electric power, need be to rotor feed-in part electric power.

6, by the described control system of claim 1, it is characterized in that variable-speed controller has the slip excitation converter, pulse width modulation inverter, dc bus, K1, K2, the K3 control contactor, wave filter is formed, slip excitation converter wherein, dc bus and pulse width modulation inverter constitute the four quadrant convertor main circuit, the topological structure of dc bus two lateral circuits is identical in the main circuit, form with IGBT inversion/rectifier bridge and drive circuit, connect by dc-link capacitance resistance between them, busbar voltage is sent voltage on generator unit stator and rotor and is decided, the voltage that generator amature sends is lower than the voltage of stator, but rotor is when the electrical network feed, circuit must adopt copped wave to boost and realize the inversion online, this circuit inserts inductance in the outlet of grid side pulse width modulation inverter, electric capacity L1, L2, L3, C1, C2, C3, combine with the IGBT pulsewidth modulation, realize the feedback of rotor low voltage electricity generation grid-connecting energy, simultaneously, these electric capacity and inductance still are the part of sine wave filter.

7, by the described control system of claim 1, it is characterized in that master controller is made up of CPU board and peripheral interface circuit plate two large divisions, little process chip of host CPU plate is TMS320F240, expanded 65K16 position program storage on the bus, 64K16 bit data storage, 12 road PMW are provided output, 2 tunnel 10 bit port A/D output, 3 16 general purpose timers outputs, system has SPI and general RS-232 interface, 16 road A/D input interfaces, expansion a slice MP7680JE interface, have 4 tunnel 12 D/A outputs, expand two SR128KX8R type flash memory devices, make system have 128*16 position SRAM program and number storage, bus hangs with 4 74ACT245 bus drivers, these device circuitry have constituted DSP high-performance numeral microprocessing systems, and the peripheral interface circuit plate is by four most of compositions, and the digital signal input is handled, buffer circuit; Analogue signal output/input gating, amplification, buffer circuit; PWM ripple output fixed ampllitude buffer circuit; Buffer circuit is amplified in switching signal output.

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