基于CPU-FPGA异构平台的虚拟同步并网逆变器实时仿真算法设计

Real-time simulation algorithm design of a virtual synchronous grid-connected inverter system based on a CPU-FPGA heterogeneous platform

随着电力系统中电力电子器件的广泛应用,对于小步长(≤2μs)电磁暂态实时仿真的需求逐渐增加。此时,单独依靠CPU已难以满足其要求,转而结合现场可编程门阵列(Field Programmable Gate Array,FPGA)来实现是一大趋势。搭建了适用于虚拟同步并网逆变器系统实时仿真的CPU-FPGA异构计算平台。其中,FPGA电路部分采用优化EMTP(Electro-Magnetic Transient Program)流程实现,综合利用恒导纳开关建模、支路拆分并行处理及矩阵化流程计算来优化仿真实时性能。CPU控制部分采用虚拟同步控制,并设计了与FPGA异步通信的数据交互接口。最后,针对该并网逆变器系统进行小步长实时仿真,与Simulink离线仿真结果相对比,同时分析平台实时性能与FPGA上资源消耗,验证了基于所提平台实现虚拟同步并网逆变器系统实时仿真的准确性与有效性。

With the wide application of power electronic devices in power systems,the demand for small time-step(≤2μs)electromagnetic transient real-time simulation increases.While a CPU is unable to meet the demand alone,there is a trend to complement it with a Field Programmable Gate Array(FPGA).A CPU-FPGA heterogeneous computing platform available for real-time simulation of virtual synchronous grid-connected inverter system is built.Within it,the circuit part on the FPGA is implemented with an optimized Electro-Magnetic Transient Program(EMTP)algorithm.Constant admittance switch modeling,branch division with parallel processing and high efficiency matrix operation are used to improve real-time performance.The control part on the CPU adopts virtual synchronization control and designs a data interaction interface for asynchronous communication with the FPGA.A small step real-time simulation of the grid-connected inverter system is conducted and compared with the results of a Simulink offline simulation.At the same time,the real-time performance of the platform and resource consumption on FPGA is analyzed.All results above can verify the accuracy and effectiveness of a real-time simulation of the virtual synchronous grid-connected inverter system based on the proposed platform.