CN105720795A - Wind power conversion control system - Google Patents

Abstract

The invention provides a wind power conversion control system which comprises a motherboard, a master control board fixed on a pin socket on the front of the motherboard through a pin, and multiple plug-in boards which are fixed on a pin socket on the back of the motherboard through pins. With the wind power conversion control system, the technical problem that centralized wind power conversion control cannot be achieved in the prior art is solved, the utilization rate of each plug-in board circuit can be ensured to the maximum through the modular design, the flexibility and security of hardware configuration are greatly improved, the layout difficulty of a complex PCB is reduced, and the cycle of product secondary development is shortened.

Description

Wind Power Converter Control System

technical field

The invention relates to the technical field of circuit control, in particular to a wind power conversion control system.

Background technique

At present, the power generation and grid connection of new energy are mainly realized through the control of converters. New energy power generation technology is gradually developing in the direction of simplification of mechanical components and complexity of power electronic control components, thus affecting the capacity and reliability of converters. Higher requirements are put forward for performance, and converter topologies such as AC-DC-AC have also been widely used in the field of converters.

However, how to carry out centralized control of wind power conversion has not yet proposed an effective solution.

Contents of the invention

An embodiment of the present invention provides a wind power conversion control system to solve the technical problem in the prior art that centralized control of wind power conversion cannot be performed. The control system includes:

motherboard;

The main control board is fixed on the pin socket on the front of the motherboard through pin pins;

A plurality of plug-in boards are fixed on the pin sockets on the reverse side of the motherboard through pin pins.

In one embodiment, the main control board includes: a DSP board and an FPGA board, and the main control board is pluggably fixed to two 96 tubes on the front of the motherboard through two 96-pin pins. pin socket.

In one embodiment, the distribution of the 96-pin pins is 3 columns, each column has 32 pin pins, and the distribution of the 96-pin sockets is 3 columns, and each column has 32 pin sockets.

In one embodiment, the model of the DSP chip in the main control board is TMS320F2812, and the model of the FPGA chip is EP4CE115F23C8.

In one embodiment, the size of the plug-in board is: 220mm×145mm.

In one embodiment, the number of the plug-in boards is 11, each of which is detachably fixed to a 96-pin socket on the reverse side of the motherboard through a 96-pin pin.

In one embodiment, the plug-in board includes at least one of the following: a power board, a signal conditioning board, a digital input and output board, a pulse signal input board, a PWM board and a protection board.

In one embodiment, the power supply board is used to supply power to other plug-in boards;

Each signal conditioning circuit in the signal conditioning board includes: a voltage follower circuit, an amplification circuit, a bias circuit and an RC filter circuit connected in sequence, for adjusting the analog signal transmitted by the sensor to a signal suitable for AD sampling;

The digital input circuit in the digital input and output board includes: TLP121 optocoupler isolation circuit, RC filter circuit and SN74CBTD3384DW level conversion chip connected in sequence, and the digital output circuit in the digital input and output board includes: 74LS244 chip connected in sequence And TLP127 optocoupler isolation circuit;

The pulse signal input board includes: TLP559 optocoupler isolation circuit, RC filter and 74HC14N level conversion chip connected in sequence, for identifying the level jump of the input pulse signal;

Each PWM board includes 7 output circuits and 2 input circuits, wherein, there are 6 output PWM waveforms in the 7 output circuits, 1 adopts HFBR-1522 optical fiber transmitter to output fault blocking signal, and the 2 The input circuit adopts HFBR-2522 optical fiber receiver to input external fault signal;

The protection board includes 4 circuits of over-protection circuits and 1 circuit of phase-frequency measurement circuits, wherein the over-protection circuit is used to compare the input electrical quantity with the threshold and then output a logic signal, and then perform optocoupler isolation through the 6n137 chip, so The phase-frequency measurement circuit is used to convert the input AC signal into a square wave signal, and output the square wave signal to a 6n137 optocoupler isolation circuit for optocoupler isolation.

In one embodiment, the power board includes: an AC/DC circuit board and a DC/DC circuit board, wherein the AC/DC circuit board is used to convert alternating current into direct current and input to the DC/DC In the circuit board, the DC/DC circuit board converts the direct current into a voltage required by other plug-in boards.

In one embodiment, the number of signal conditioning boards is 2n, and each signal conditioning board includes 8 channels of conditioning signals, where n is an integer greater than or equal to 2.

In the embodiment of the present invention, a wind power conversion control system is provided, in which a motherboard, a main control board and a plug-in board are provided, and the main control board and the plug-in board are inserted into the socket of the motherboard through pins to form a complete The modularized control system not only realizes the control of grid-connected wind turbines, energy storage and switching power converters, but also solves the technical problem that the wind power converter cannot be controlled in a centralized manner in the prior art. The modular design can also maximize the utilization rate of each plug-in board circuit, greatly improve the flexibility and safety of hardware configuration, reduce the difficulty of complex PCB board layout, and shorten the cycle of secondary development of products.

Description of drawings

The drawings described here are used to provide further understanding of the present invention, constitute a part of the application, and do not limit the present invention. In the attached picture:

Fig. 1 is a schematic diagram of the composition and structure of a wind power conversion control system according to an embodiment of the present invention.

Fig. 2 is a front interface diagram of the motherboard of the embodiment of the present invention.

Fig. 3 is a diagram of the interface on the back of the motherboard according to the embodiment of the present invention.

Fig. 4 is a specification diagram of the plug-in board according to the embodiment of the present invention.

FIG. 5 is a schematic diagram of signals of the power board A of the embodiment of the present invention.

FIG. 6 is a schematic diagram of signals of a power board B according to an embodiment of the present invention.

FIG. 7 is a signal schematic diagram of a signal conditioning board according to an embodiment of the present invention.

FIG. 8 is a schematic diagram of signals of a digital input and output board according to an embodiment of the present invention.

Fig. 9 is a signal schematic diagram of the pulse signal input board according to the embodiment of the present invention.

FIG. 10 is a schematic diagram of signals of a PWM board according to an embodiment of the present invention.

Fig. 11 is a schematic diagram of signals of the protection board according to the embodiment of the present invention.

Fig. 12 is a schematic diagram of the overall signal of the embodiment of the present invention.

Fig. 13 is a schematic diagram for doubly-fed wind generator control according to an embodiment of the present invention.

detailed description

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be described in further detail below in conjunction with the embodiments and accompanying drawings. Here, the exemplary embodiments and descriptions of the present invention are used to explain the present invention, but not to limit the present invention.

In this example, a wind power conversion control system is provided, as shown in Figure 1, which mainly includes:

motherboard 101;

The main control board 102 is fixed on the pin socket on the front of the motherboard through pin pins;

A plurality of plug-in boards 103 are fixed on the pin sockets on the reverse side of the motherboard through pin pins.

That is, a converter control system based on modular design is provided to carry out modular and generalized design of complex power signal processing circuits, and design each power signal processing process into a modular PCB plug-in board, thereby Improve the simplicity of circuit design, the flexibility of configuration and the versatility of use.

As shown in Figure 1, the main control board adopts the "DSP+FPGA" design method, DSP is used as the main processor and communicates with the upper PC, FPGA is used as a coprocessor, and the peripheral circuits of the main control board are called plug-in boards. In this converter control system, 11 plug-in boards can be set. In order to facilitate signal measurement, the circuit composed of sensors is designed as a measurement board. The number of measurement boards can be determined by the number of signals.

In this example, according to the overall circuit structure and signal processing functions of the converter control system, the entire hardware platform is divided into areas, mainly including the above-mentioned main control board, motherboard and multiple plug-in boards.

Among them, the main control board is a dual-core main control board with DSP and FPGA chips. The model of the DSP chip can be selected as TMS320F2812, and the model of the FPGA chip can be selected as EP4CE115F23C8. The main control board can be fixed on the On the front of the motherboard, 96 pins are distributed in 3 columns, each column has 32 pins. Motherboard specifications: 83Δ×140mm (1△=5.08mm), with two 96-pin sockets on the front and eleven 96-pin sockets on the back. The motherboard is used as a carrier for fixing the main control board and the plug-in board. Also used as a medium for signal transfer, as shown in Figure 1, each signal is input from the plug-in board, calculated and processed by the main control board, and then output from the plug-in board to external circuits such as converters. However, it is worth noting that the chip model, the number of plug-in boards, the number of pins, etc. involved in this example are all to better illustrate the present invention and do not constitute an improper limitation of the present invention. Other types of chips, or other numbers of plug-in boards, and other numbers of pins. As shown in Figure 2 is the front interface diagram of the motherboard, there are two 96-pin sockets, and the main control board is fixed on the motherboard through these two sockets. As shown in Figure 3, there are 11 sockets with 96 pins, which correspond to the fixed positions of 11 plug-in boards.

In this example, 11 plug-in boards can be set in the control system, as shown in Figure 4, the specifications of each plug-in board can be set as: 220mm×145mm, and they are inserted into the back of the motherboard through a single 96-pin pin, of which , These 11 plug-in boards can be divided into three categories: power supply, analog signal and digital signal. The three categories are described in detail below:

1) Plug-in board for power supply

As shown in Figure 1, the power plug-in boards include: power board A and power board B. Further, considering the different sizes and voltage levels of the onboard power supply modules, in this example, the power supply plug-in boards are divided into: AC/DC circuit board (power supply board A) and DC/DC circuit board (power supply board A) B), where:

1-1) Power board A plug-in board can use wide voltage input (18V ~ 36V) Weidmüller 100W AC/DC switching power supply module, use AC EMC filter to filter out harmonics, convert 220V AC into 24V DC, Power supply board B conversion;

Specifically, as shown in Figure 5 is the signal schematic diagram of the power board A, the input is 220V AC mains, the harmonics are filtered by the EMC filter first, and then the wide input Weidmüller AC/DC switching power supply, the The 220V AC power becomes 24V DC power, which is finally output to the power board B after passing through the RC filter circuit.

1-2) The plug-in board of power board B can use Jinshengyang 20W switching power supply module with wide voltage input to convert the 24V DC converted by power board A into three voltages: 5V digital power supply, ±15V analog power supply, and 24V switching power supply for other The plug-in board is powered, and magnetic beads can be used as a DC filter to filter out high-frequency interference.

Specifically, as shown in Figure 6 is the signal schematic diagram of power board B. Its input is the 24V DC output from power board A. After being filtered by the EMC filter, it enters the Jinshengyang switching power supply module with four wide inputs, and outputs 5V digital power respectively. , +15V analog power supply, -15V analog power supply and 24V switching power supply, respectively supply power for each plug-in board.

2) Plug-in boards for analog signals

As shown in Figure 1, the plug-in boards for analog signals can include: signal conditioning board A, signal conditioning board B, signal conditioning board C, and signal conditioning board D, and the designs of these four signal conditioning boards are the same, and the actual use At this time, the number of signal conditioning boards can be 6, 8, etc., as long as it is an even number greater than or equal to 4.

The analog signal plug-in board is mainly used to adjust the analog signal transmitted by the sensor to a signal suitable for AD sampling, so it is called a signal conditioning board. Among them, each signal conditioning board has 8 channels of signal conditioning circuits. Considering that in this example, the sampling channels of the control system can reach up to 32 channels, so 4 signal conditioning boards are needed. Each signal conditioning circuit is composed of a voltage follower circuit, an amplifier circuit and a bias circuit, and an RC circuit is used for filtering.

As shown in Fig. 7 is a signal schematic diagram of the signal conditioning board, each signal conditioning board has 8 signal conditioning circuits. The current measured by the current sensor and the voltage measured by the voltage sensor are used as signal input. First, the harmonics are filtered by the RC circuit, and then the signal is conditioned by the voltage follower circuit, the amplifier circuit and the bias circuit, and finally after the RC filter circuit. Input to the control system for AD sampling.

3) Plug-in boards for digital signals

As shown in Figure 1, digital signal plug-in boards can include: digital input and output boards, pulse signal input boards, PWM board A, PWM board B, and protection boards, among which:

3-1) The digital input and output board is the digital signal input and output port of the control cabinet. It mainly collects the switching value of the external relay and outputs the control value of the control switch. It is used in the control of the wind turbine grid-connected switch. In this example, the digital input and output board can be divided into two parts: the digital input circuit and the output circuit. Among them, the digital input circuit has a total of 8 channels. The signal is sent to the SN74CBTD3384DW level conversion chip, and finally the signal is sent to the control system. There are 8 digital output circuits in total. Each output signal enters the 74LS244 chip first, and then is isolated by the TLP127 optocoupler and then output to the peripheral circuit. Furthermore, the digital input and output board can also be used as an external expansion board for PWM. When the number of PWM channels in the control cabinet exceeds 12, the digital input and output board can be used to add another 8 channels.

As shown in Figure 8 is the signal schematic diagram of the digital input and output board. The signal input part has 8 signal input circuits. After processing by the level conversion chip, it is input to the control system. The signal output part also has 8 output circuits. The signal processing process is opposite to the input process. The signal to be output by the control system is first processed by the 74LS244N chip, and then output after RC filtering, optocoupler isolation and RC filtering.

3-2) The pulse signal input board is a fast digital input and output board. It can quickly identify the level jump of the input pulse signal and input it to the control system for capture. It is generally used for the input of the motor photoelectric encoder signal. The rotor speed of the motor as well as the rotor position can be calculated. Among them, the pulse signal input board has a total of 8 input ports, and each input port adopts RC filter and TLP559 optocoupler isolation. No. 5 and No. 6 are mutual backups. After jumper selection, No. 7 and No. 8 have no jumper, that is, the control system can receive up to 5 pulse signals at the same time. The pulse signal isolated by the optocoupler enters the level conversion chip 74HC14N for processing and then enters the control system.

As shown in Figure 9 is the signal schematic diagram of the pulse signal input board, where EXA and /EXA are a pair of complementary signals, which are selected by jumpers. Similarly, EXB and /EXB are a pair of complementary signals, and EXZ and /EXZ are a pair of complementary signals. pair of complementary signals. Each input circuit is the same, and the input signal passes through RC filter, optocoupler isolation and RC filter in turn, and then enters the 74HC14N chip for processing, and finally enters the control system.

3-3) PWM board, as shown in Figure 1, includes: PWM board A and PWM board B, the design of the two is the same, the main function is to output PWM waves to drive the power module, and each PWM plug-in board has 7 outputs circuit and 2 input circuits, of which, 6 of the 7 output circuits output PWM waveforms, and 1 outputs the fault blocking signal. Using the optical fiber transmitter HFBR-1522 to convert the electrical signal into an optical signal can reduce the primary system and secondary Crosstalk between secondary control systems. The input of the 2-way input circuit is an external fault signal, which is used to block the PWM output module, and the optical fiber receiver HFBR-2522 is used.

As shown in Figure 10, the signal diagram of the PWM board is shown. Each PWM board has 6 channels of PWM output circuits. The circuit signal is first isolated by the optocoupler, and then input to the optical fiber transmitter, the electrical signal is converted into an optical signal and output to the converter.

3-4) The protection board is used to protect the overvoltage and overcurrent of the entire control system, including 4 circuits of excessive protection circuits and 1 circuit of phase frequency measurement circuit, wherein the circuit for excessive protection compares the input electrical quantity with the threshold Output logic signal, and then through 6n137 chip for optocoupler isolation, input to the control system, the phase frequency measurement circuit converts the input AC signal into a square wave signal, and then input to the control system after 6n137 optocoupler isolation, for the control system to calculate the input AC signal Frequency of.

As shown in Figure 11 is the signal schematic diagram of the protection board, there are 4 circuits of excessive protection circuit and 1 circuit of phase frequency measurement circuit on the protection board, wherein, the signal input by each circuit of excessive protection circuit is three-phase voltage or three-phase current, after excessive After the protection module generates an over-protection signal, the over-protection signal is input to the control system after being isolated by the optocoupler. The input signal of the phase-frequency measurement circuit is a three-phase sinusoidal voltage. After passing through the phase-frequency measurement module, the three sinusoidal signals are processed into three pulse signals. Each pulse signal is isolated by an optocoupler and then input to the control system for capture and calculation.

Figure 12 is a schematic diagram of the entire signal processing of the wind power conversion control system. The following will take the wind power conversion control system shown in Figure 12 to control the DFIG wind turbine shown in Figure 13 as an example, including:

1) The DSP first sends the AD sampling command ADSTART to the FPGA, and the FPGA sends the command to the off-chip sampling chip AD7606, and then the voltage sensor LV25-P and the current sensor LA100-P respectively collect the voltage and current values of the machine-side converter and the network test converter The voltage and current values and the DC bus voltage value are sent to the off-chip sampling chip AD7606 on the main control board after passing through the signal conditioning board for AD conversion, and finally the converted sampling value is sent to the FPGA, and the FPGA then sends the sampling value to the DSP, thus completing AD sampling.

2) For the speed and position measurement of the DFIG rotor and the frequency measurement of the grid voltage, the frequency measurement module can be used to complete. A photoelectric code disc is installed on the motor rotor. When the rotor rotates, a square wave signal is generated. After being collected by the pulse signal input board, it is sent to the DSP through the FPGA. The DSP capture circuit is used to capture the signal, and the rotor speed and position are calculated through the program. When measuring the frequency of the grid voltage, the voltage is first converted from a sinusoidal signal to a square wave signal by the phase-frequency measurement circuit of the protection board, which is also collected by the pulse signal input board and sent to the FPGA, and then sent to the DSP for processing and calculating the frequency.

3) After the DSP obtains the AD sampling value, it is sent to the control program for processing. The control program first performs coordinate transformation on the sampling value to achieve decoupling, and then uses the PI program to perform closed-loop adjustment to generate the command voltage value, and finally uses the space vector pulse width modulation SVPWM And DSP time manager EV to generate the corresponding PWM wave. The generated PWM wave is converted and processed by PWM board A and PWM board B, and the electrical signal is converted into an optical signal to drive the network converter and the machine-side converter respectively to realize the control of the DFIG wind turbine.

4) The input signal of the protection board of the control system is the voltage, current and DC bus voltage of the grid-side converter and the machine-side converter, and whether an overvoltage or overcurrent fault occurs is determined through the protection circuit on the protection board. If a fault occurs, the protection board sends a fault blocking signal to the PWM board to block the output of the PWM, and at the same time sends a fault blocking signal to the time manager of the DSP to turn off the generation of the PWM. If this control cabinet is used to control the single-stage converter, only one PWM board is required, and the number of AD sampling channels is correspondingly reduced. For plug-in boards that do not need to be used, they can be directly pulled out from the control cabinet without affecting the entire control system. The operation is convenient and flexible.

In the above embodiments, the number of PWM channels output by the wind power conversion control system is not limited by the fixed resources of DSP, and can be expanded through FPGA, and the compatibility and flexibility of signal acquisition, protection, processing, etc. are improved as much as possible. And versatility, in addition to being used in wind power conversion experiments, the platform can also be used in power conversion control fields such as new energy power generation, energy storage, and switching power supplies. In addition, due to the separate design of each functional circuit, flexible configuration and combination can be realized, and it can also be used to connect with RTDS to form a digital-analog hybrid simulation system.

From the above description, it can be seen that the embodiments of the present invention achieve the following technical effects: a wind power conversion control system is provided, in which a motherboard, a main control board and a plug-in board are provided, and the main control board and the plug-in board are both A complete modular control system is formed by inserting the pins into the socket of the motherboard, which not only can realize the control of the grid-connected wind turbine, energy storage and switching power converter, but also solves the problem that cannot be solved in the prior art. For the technical problem of centralized control of wind power conversion, the modular design can also maximize the utilization rate of each plug-in board circuit, greatly improve the flexibility and safety of hardware configuration, and reduce the layout of complex PCB boards The problem of difficulty shortens the cycle of product secondary development.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, various modifications and changes may be made to the embodiments of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (10)

1. A wind power conversion control system, characterized in that, comprising: motherboard; The main control board is fixed on the pin socket on the front of the motherboard through pin pins; A plurality of plug-in boards are fixed on the pin sockets on the reverse side of the motherboard through pin pins. 2. The wind power converter control system according to claim 1, wherein the main control board includes a DSP chip and an FPGA chip, and the main control board is pluggable through two 96-pin pins. Secured to two 96-pin sockets on the front of the motherboard. 3. The wind power conversion control system according to claim 2, wherein the distribution of the 96 pins is 3 columns, each column has 32 pins, and the distribution of the 96 pin sockets is 3 columns , 32 pin jacks per row. 4 . The wind power conversion control system according to claim 2 , wherein the model of the DSP chip in the main control board is TMS320F2812, and the model of the FPGA chip is EP4CE115F23C8. 5. The wind power conversion control system according to any one of claims 1 to 4, wherein the size of the plug-in board is: 220mm×145mm. 6. The wind power conversion control system according to any one of claims 1 to 4, wherein the number of said plug-in boards is 11, and each of them is pluggably fixed on each of the 96-pin pins. a 96-pin socket on the reverse side of the motherboard described above. 7. The wind power conversion control system according to any one of claims 1 to 4, wherein the plug-in board includes at least one of the following: power board, signal conditioning board, digital input and output board, pulse signal input board, PWM board and protection board. 8. The wind power conversion control system according to claim 7, characterized in that: The power board is used to supply power to other plug-in boards; Each signal conditioning circuit in the signal conditioning board includes: a voltage follower circuit, an amplification circuit, a bias circuit and an RC filter circuit connected in sequence, for adjusting the analog signal transmitted by the sensor to a signal suitable for AD sampling; The digital input circuit in the digital input and output board includes: TLP121 optocoupler isolation circuit, RC filter circuit and SN74CBTD3384DW level conversion chip connected in sequence, and the digital output circuit in the digital input and output board includes: 74LS244 chip connected in sequence And TLP127 optocoupler isolation circuit; The pulse signal input board includes: TLP559 optocoupler isolation circuit, RC filter and 74HC14N level conversion chip connected in sequence, for identifying the level jump of the input pulse signal; Each PWM board includes 7 output circuits and 2 input circuits, wherein, there are 6 output PWM waveforms in the 7 output circuits, 1 adopts HFBR-1522 optical fiber transmitter to output fault blocking signal, and the 2 The input circuit adopts HFBR-2522 optical fiber receiver to input external fault signal; The protection board includes 4 circuits of over-protection circuits and 1 circuit of phase-frequency measurement circuits, wherein the over-protection circuit is used to compare the input electrical quantity with the threshold and then output a logic signal, and then perform optocoupler isolation through the 6n137 chip, so The phase-frequency measurement circuit is used to convert the input AC signal into a square wave signal, and output the square wave signal to a 6n137 optocoupler isolation circuit for optocoupler isolation. 9. The wind power conversion control system according to claim 7, wherein the power board comprises: an AC/DC circuit board and a DC/DC circuit board, wherein the AC/DC circuit board is used for The alternating current is converted into direct current and input into the DC/DC circuit board, and the DC/DC circuit board converts the direct current into the voltage required by other plug-in boards. 10. The wind power conversion control system according to claim 7, wherein the number of the signal conditioning boards is 2n, and each signal conditioning board includes 8 conditioning signals, wherein n is greater than or equal to 2 integer.