Wind turbine full closed loop simulator and method based on field programmable gate array

Abstract

The application belongs to the technical field of wind turbine simulation, and provides a wind turbine full-closed loop simulator and method based on a field programmable gate array, which comprises a field programmable gate array chip, an ARM chip and a digital-analog interface connected with the field programmable gate array chip; the application adopts the field programmable gate array chip, and realizes transient real-time simulation of the electromagnetic system of the wind turbine by means of the powerful parallel computing capability of the field programmable gate array chip; compared with the prior art, the application can quickly verify the effect of the control strategy by using the built-in controller, and can access the actual wind turbine controller through the digital-analog interface to perform hardware-in-the-loop simulation and test the control effect; meanwhile, the ARM chip is used as a real-time operation carrier of the wind turbine controller algorithm, and the field programmable gate array chip and the ARM chip interact with real-time data through a digital-analog channel to realize a wind turbine closed loop real-time simulation platform.

Description

Technical Field

[0001] This invention belongs to the field of wind turbine simulation technology, and particularly relates to a wind turbine full closed-loop simulator and method based on field programmable gate array. Background Technology

[0002] Wind power has become one of the world's largest renewable energy sources, playing a crucial role in future electricity supply. With the development of related technologies, the capacity and size of wind turbine units are gradually increasing, significantly increasing the difficulty of wind turbine design and testing. Therefore, there is an urgent need to deeply study wind turbine simulation technology to optimize and improve the design process and testing accuracy of large-scale wind turbines. Based on real-time simulation technology, hardware-in-the-loop simulation of wind turbines can improve testing accuracy and the safety of the testing process, while reducing testing costs. For example, using real-time electromagnetic transient simulation of the turbine for hardware-in-the-loop testing of the grid-connected controller can improve simulation confidence and increase testing efficiency. Furthermore, building a real-time computing platform for wind turbine controllers can greatly facilitate the testing of control strategies.

[0003] The electromagnetic system of a wind turbine includes various components with transient time scales on the microsecond level, such as generators, converters, transformers, and circuit breakers. The switching frequency of wind turbine converters is typically in the kilohertz range; these high-frequency switching state changes pose a significant challenge to the calculation of electromagnetic transient models. In general, the characteristics and difficulties of real-time electromagnetic transient simulation of wind turbines lie in the short model time scale and the large computational load. Meanwhile, the calculation of the turbine controller is characterized by logical complexity but relatively low computational load.

[0004] The inventors discovered that, to address the issue of real-time simulation of wind turbines, existing inventions have mentioned using FPGAs for real-time simulation of wind turbine models. However, this approach lacks a method for constructing the turbine controller, relying solely on an external controller to achieve closed-loop simulation, resulting in a cumbersome and inconvenient testing process. Other inventions have proposed methods for building turbine controllers based on DSP platforms, combining them with wind turbine-to-tow experimental platforms to create a closed-loop real-time simulation platform. However, due to the high development difficulty of DSPs, this approach is not conducive to the development of novel control algorithms. None of the above solutions facilitate convenient closed-loop real-time simulation of wind turbines. Existing literature proposes using FPGAs for real-time simulation of the electromagnetic system of wind turbines, but changes to circuit parameters in existing solutions require recompiling the FPGA program, which is extremely time-consuming, averaging up to 24 hours, significantly limiting the flexibility of the simulation. Furthermore, while mature commercial simulation platforms like RTDS and RT-Lab can perform closed-loop real-time simulation of wind turbines, their hardware and software costs are very high. Summary of the Invention

[0005] To address the aforementioned problems, this invention proposes a wind turbine full closed-loop simulator and method based on a field-programmable gate array (FPGA). This simulator can be used for rapid verification of wind turbine control algorithm strategies and hardware-in-the-loop simulation verification of actual controllers. It solves the problems of inconvenient testing of wind turbine control algorithms and complex hardware-in-the-loop simulation processes in existing technologies. The equipment involved in this invention has low cost and high economic efficiency.

[0006] To achieve the above objectives, in a first aspect, the present invention provides a wind turbine generator full closed-loop simulator based on a field-programmable gate array (FPGA), employing the following technical solution:

[0007] A wind turbine generator full closed-loop simulator based on field-programmable gate array (FPGA) includes an FPGA chip, an ARM chip and a digital-to-analog interface connected to the FPGA chip;

[0008] The field-programmable gate array chip is used for transient real-time simulation of the electromagnetic system of wind turbine generators.

[0009] The ARM chip is used for real-time computation of the wind turbine controller algorithm; the ARM chip and the field-programmable gate array chip exchange real-time data through a digital-to-analog channel;

[0010] The digital-to-analog interface is used to connect to an external actual wind turbine controller.

[0011] Furthermore, the programmable gate array chip includes a state controller for identifying the current state of the simulator, an electromagnetic transient simulation algorithm for real-time calculation of electromagnetic transient processes, and a real-time simulation controller for timing.

[0012] Furthermore, when the programmable gate array chip receives instructions from the host computer, it switches between four states: waiting, running, stopping, and outputting results. When an abnormality occurs inside the simulator that does not affect the simulation, the state controller is placed in the abnormal state, but the simulation still proceeds. When an abnormality occurs inside the simulator that affects the simulation, the state controller is placed in the error state and the simulation stops.

[0013] Furthermore, the electromagnetic transient simulation algorithm is based on the multi-zone Thevenin equivalent method, which divides the electromagnetic system of the wind turbine into multiple subsystems. There is no data dependency between the multiple subsystems, thereby realizing the parallel computation of the electromagnetic system of the wind turbine.

[0014] Furthermore, the programmable gate array chip is connected to an ETH1 network interface; the inverse matrix of the admittance matrix and the simulation parameters are pre-calculated in the host computer for all switching states, and the host computer software sends the data to the simulator through the ETH1 network interface, and the programmable gate array chip stores the inverse of the admittance matrix and the simulation parameters.

[0015] Furthermore, once the timing of the real-time simulation controller reaches the simulation step size, the control electromagnetic transient simulation algorithm begins to calculate.

[0016] Furthermore, the programmable gate array (PGA) chip is connected to a memory; after receiving an initialization command from the host computer, the PGA chip retrieves predefined simulation parameters from the memory and stores them in the PGA chip.

[0017] Furthermore, after each simulation step cycle, the programmable gate array chip calculates the index value of the inverse matrix of the admittance matrix based on the current switching state of the switching element, and retrieves the corresponding admittance matrix from the memory for simulation calculation.

[0018] Furthermore, when connected to an external actual wind turbine controller, the programmable gate array chip automatically shields the data transmission path of the ARM chip and automatically switches to the data transmission path with the digital-to-analog interface.

[0019] To achieve the above objectives, in a second aspect, the present invention also provides a fully closed-loop simulation method for wind turbine generators based on field-programmable gate arrays, employing the following technical solution:

[0020] A closed-loop simulation method for wind turbines based on field-programmable gate arrays is provided, which employs the closed-loop simulator for wind turbines based on field-programmable gate arrays as described in the first aspect.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] 1. This invention employs a field-programmable gate array (FPGA) chip. Leveraging the powerful parallel computing capabilities of the FPGA chip, it achieves transient real-time simulation of the electromagnetic system of a wind turbine. Compared to existing technologies, it can quickly verify the effectiveness of control strategies using a built-in controller. Furthermore, it can connect to an actual wind turbine controller via a digital-to-analog interface for hardware-in-the-loop simulation to test its control performance. Simultaneously, an ARM chip serves as the real-time computation carrier for the wind turbine controller algorithm, exchanging real-time data with the FPGA chip through a digital-to-analog channel, thus realizing a closed-loop real-time simulation platform for wind turbines.

[0023] 2. This invention designs a closed-loop real-time wind turbine simulator based on an FPGA-ARM heterogeneous computing platform, simultaneously considering wind turbine simulation and controller implementation. Compared to existing technologies, this simulator can quickly verify the effectiveness of control strategies using a built-in controller, and can also connect to actual wind turbine controllers for hardware-in-the-loop simulation to test their control effects. Leveraging the powerful parallel computing capabilities of the FPGA, this simulator achieves transient real-time simulation of the wind turbine's electromagnetic system. It implements a reconfigurable function that allows modification of simulation parameters without recompiling the FPGA program, greatly improving the simulator's ease of use. Simultaneously, the simulator incorporates an ARM-based controller unit as the real-time computation carrier for the wind turbine controller algorithm. Real-time data exchange between the FPGA and the ARM platform via a digital-to-analog channel realizes a closed-loop real-time simulation platform for wind turbines. The simulator also incorporates a multi-channel digital-to-analog converter interface, enabling real-time data interaction between the simulator and external devices. Attached Figure Description

[0024] The accompanying drawings, which form part of this embodiment, are used to provide a further understanding of this embodiment. The illustrative embodiments and their descriptions are used to explain this embodiment and do not constitute an improper limitation of this embodiment.

[0025] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present invention. Detailed Implementation

[0026] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0027] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0028] FPGA: Field Programmable Gate Array, a type of computing hardware that is more efficient than a CPU but more complex to program; ARM: A type of computing hardware.

[0029] Example 1:

[0030] like Figure 1 As shown, this embodiment provides a wind turbine fully closed-loop simulator based on a field-programmable gate array (FPGA), including a PCB main circuit board, an FPGA chip, an ARM chip, a 4Gb SDRAM memory, a network interface, an SPWM modulation chip, and a digital-to-analog converter module. The PCB main circuit board is used to implement hard-wiring between the various hardware components. The simulator system is described below in three parts: the functions and implementation of the FPGA chip, the functions and implementation of the ARM chip, and the data interaction and interconnection interfaces between the various hardware components.

[0031] FPGA chip functions and their implementation:

[0032] The FPGA chip implements a state controller to identify the current state of the simulator, which is divided into six states: waiting, running, stopped, result output, exception, and error. When the FPGA chip receives an instruction from the host computer, it transitions between the four states of waiting, running, stopped, and result output. When an exception occurs within the simulator that does not affect the simulation, the state controller is placed in the exception state and a yellow LED is lit, but the simulation continues. When an exception occurs within the simulator that affects the simulation, the state controller is placed in the error state, a red LED is lit, and the simulation stops.

[0033] The FPGA chip can be embedded with an electromagnetic transient simulation algorithm for real-time calculation of electromagnetic transient processes in 10-microsecond steps. This algorithm is used to solve electromagnetic transient models of components in a wind turbine, such as generators, converters, transformers, circuit breakers, filters, crowbars, and infinite power supplies. The electromagnetic transient models can be modeled based on typical EMT methods.

[0034] To maximize the advantages of FPGA parallel computing, the electromagnetic transient simulation algorithm is based on the multi-zone Thevenin equivalent method, dividing the unit's electromagnetic system into multiple subsystems with no data dependency between them, thus achieving parallel computation of the electromagnetic system. Furthermore, in other embodiments, leveraging the fine-grained parallel hardware features of FPGA, the algorithm for each subsystem is optimized for parallelization, achieving efficient operation of each subsystem.

[0035] In the electromagnetic transient algorithm, the converter modeling can traditionally employ the Ron / Roff high-precision modeling method. However, this modeling method causes the circuit admittance matrix to change over time during simulation, making it impossible for the FPGA chip to perform real-time calculations. Therefore, in this embodiment, the inverse matrix of the admittance matrix and the simulation parameters are pre-calculated in the host computer for all switching states. The host computer software sends the data to the simulator via the ETH1 network interface, and the parameter pre-storage module in the FPGA chip stores the inverse admittance matrix and the simulation parameters in the SDRAM memory.

[0036] The FPGA chip implements a DDR4-based SDRAM memory control unit to control the process of retrieving data from the SDRAM and writing simulation results into the SDRAM. The FPGA chip also implements a UDP-based network controller to control the ETH1 network interface.

[0037] The FPGA chip implements a real-time simulation controller for high-precision microsecond-level timing. Specifically, once the timing reaches the simulation step size, the electromagnetic transient simulation algorithm begins calculation; this is the key module for achieving real-time electromagnetic transient simulation.

[0038] After receiving the initialization command from the host computer, the FPGA chip retrieves predefined simulation parameters from the SDRAM memory via the DDR4 controller and stores them in predefined registers within the FPGA. This implementation ensures the FPGA's reconfigurability. Upon receiving the start calculation command from the host computer, the FPGA chip automatically begins real-time simulation. At the end of each simulation step, the FPGA chip calculates the index value of the inverse admittance matrix based on the current switching state of the switching element, retrieves the corresponding admittance matrix from the SDRAM, and passes it to the electromagnetic transient algorithm unit for simulation calculation.

[0039] The FPGA chip implements an SPI bus communication controller module, which is used to control the SPI bus communication between the FPGA chip and the ARM chip.

[0040] The FPGA chip implements a simulation result storage module, which stores the calculation results of each step of the electromagnetic transient simulation algorithm in SDRAM memory. After the simulation is completed, the corresponding simulation results are retrieved from SDRAM memory via DDR4 controller and sent back to the host computer via network controller.

[0041] The FPGA chip is connected to the SDRAM memory, ETH1 network interface, ARM chip, SPWM modulation chip, and AD / DA conversion chip via onboard hardwired connections. All onboard hardwired connections are low-voltage signal lines, and the number of hardwired lines is determined by the number of pins of the interconnected chips.

[0042] ARM chip functions and implementation:

[0043] The ARM chip is used to implement real-time calculation of wind turbine control algorithms. In some embodiments, a driver program and a code conversion program are set up for the ARM chip to support the development of graphical control algorithms based on Matlab / Simulink and the development of control algorithms based on C language. This enables the function of building a controller model in Simulink and compiling and downloading it to the ARM chip with one click.

[0044] The ARM chip implements an SPI controller to implement the SPI bus protocol for data interaction with the FPGA.

[0045] The ARM chip implements a network controller, which controls the ETH2 network interface to establish a connection between the ARM chip and the host computer. The host computer builds the corresponding control strategy algorithm, converts and compiles it, and then sends it to the ARM chip via the network interface. The algorithm container then performs real-time calculations of the control strategy. Simultaneously, during the simulation phase, the network controller can also receive active and reactive power reference values ​​from the wind turbine generators from the field-level controller.

[0046] Data interaction and interconnection interfaces between various hardware components:

[0047] The FPGA chip and the ARM chip communicate bidirectionally via an SPI bus. The electromagnetic transient simulation algorithm in the FPGA chip transmits control measurements to the ARM chip in real time via the SPI bus. These control measurements may include generator stator three-phase voltage, generator stator three-phase current, generator rotor three-phase current, generator speed, generator rotor mechanical angle, grid-side converter three-phase current, grid-side converter three-phase voltage, DC bus voltage, and machine-side converter three-phase voltage. The control strategy in the ARM chip calculates the current grid-side / machine-side converter three-phase voltage reference value, crowbar control quantity, and DC chopper control quantity based on these control measurements. Simultaneously, the control strategy in the ARM chip calculates the circuit breaker's switching state. The converter's three-phase voltage reference value calculated by the ARM chip is transmitted via onboard hardwiring to the SPWM modulation chip to modulate a PWM switching signal, and then transmitted to the FPGA chip via onboard hardwiring. The crowbar control quantity, DC chopper control quantity, and circuit breaker switching state calculated by the ARM chip are sent back to the FPGA chip via the SPI bus.

[0048] When the simulator is connected to an external controller, the FPGA chip automatically shields the data transmission path of the ARM chip and automatically switches to the data transmission path with the AD / DA signal conversion chip. The FPGA chip and the external controller achieve bidirectional communication via a digital-to-analog interface. The FPGA chip transmits the aforementioned control measurement values ​​to the DA signal conversion chip via onboard hardwiring. The DA signal conversion chip converts these values ​​into analog signals and responds in the digital-to-analog interface. The external controller samples the control measurement values ​​by measuring data at the digital-to-analog interface and calculates the control signals. The external controller transmits the PWM switching signal, crowbar control quantity, DC chopper control quantity, and circuit breaker switch status to the AD chip via the digital-to-analog interface, and further transmits them to the FPGA chip via onboard hardwiring. This achieves hardware-in-the-loop simulation of the controller using this simulator.

[0049] Example 2:

[0050] This embodiment provides a wind turbine full closed-loop simulation method based on field-programmable gate arrays, which adopts the wind turbine full closed-loop simulator based on field-programmable gate arrays as described in Embodiment 1.

[0051] The above description is merely a preferred embodiment of this practice and is not intended to limit the scope of this practice. Various modifications and variations can be made to this practice by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this practice should be included within the protection scope of this practice.

Claims

1. A field programmable gate array based full closed loop wind turbine simulator, characterized in that, The programmable gate array chip comprises a state controller for identifying a current simulator state, an electromagnetic transient simulation algorithm for calculating an electromagnetic transient process in real time, and a real-time simulation controller for timing. The programmable gate array chip is used for transient real-time simulation of an electromagnetic system of a wind turbine generator. The electromagnetic transient simulation algorithm divides the electromagnetic system of the wind turbine generator into multiple subsystems based on a multi-region Thevenin equivalent method, and realizes parallel computation of the electromagnetic system of the wind turbine generator without data dependency between the multiple subsystems. The ARM chip is used for real-time operation of a wind turbine generator controller algorithm. The programmable gate array chip automatically shields a data transmission path of the ARM chip and automatically switches to a data transmission path of the digital-analog interface. The digital-analog interface is used for connecting an external actual wind turbine generator controller.

2. The field programmable gate array based full closed loop wind turbine simulator of claim 1, wherein, When the programmable gate array chip receives a host computer instruction, it is switched among four states of waiting, running, stopping and result output.

3. The field programmable gate array based full closed loop wind turbine simulator of claim 1, wherein, When an abnormality occurs in the simulator without affecting simulation, the state controller is placed in an abnormal state, but the simulation is still performed.

4. The field programmable gate array based full closed loop wind turbine simulator of claim 1, wherein, When an abnormality occurs in the simulator affecting the simulation, the state controller is placed in an error state and the simulation is stopped.

5. The field programmable gate array based full closed loop wind turbine simulator of claim 1, wherein, The programmable gate array chip is connected with an ETH1 network interface.

6. The field programmable gate array based full closed loop wind turbine simulator of claim 5, wherein, The host computer software downloads data to the simulator through the ETH1 network interface, and the programmable gate array chip stores the inverse of the admittance matrix and the simulation required parameters.

7. A field programmable gate array based full closed loop simulation method for wind turbine generators characterized in that, When the timing of the real-time simulation controller reaches the simulation step, the electromagnetic transient simulation algorithm starts to calculate. The programmable gate array chip is connected with a memory. After the programmable gate array chip receives the initialization instruction issued by the host computer, it takes the predefined simulation parameters from the memory and stores them in the programmable gate array chip. After each simulation step period arrives, the programmable gate array chip calculates the index value of the inverse of the admittance matrix according to the switching state of the current switching element, takes the corresponding admittance matrix from the memory for simulation calculation. The wind turbine generator full closed loop simulator based on the field programmable gate array is adopted.

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