基于FPGA实时仿真的光储独立直流微电网协调控制策略

Cooperative Control Strategy Based on FPGA Real-time Simulation for PV-ESS Independent DC Microgrid

现场可编程门阵列(field-programmable gate array, FPGA)具有数据并行度高、运行频率高等优点,可以满足电力系统微秒级步长的精细化仿真需求,在微电网实时仿真中展现出巨大潜力。为了深入研究光储微网中光伏和储能系统的动态特性,基于FPGA设计了光储独立低压直流微电网实时仿真系统。首先搭建了低压直流微电网实时仿真框架,设计了一系列电气系统典型模块。其次考虑到实时仿真的不同动态需求,搭建了涵盖多种控制策略的光储控制系统模型。然后在此基础上提出了基于直流母线信号(DC bus signaling, DBS)的分层协调控制策略,通过协调光储变换器的控制策略平衡系统能量流动。最后将FPGA实时仿真结果和Simulink软件作对比,一方面验证了FPGA实时仿真器的精确性和可靠性,另一方面也验证了分层协调控制策略可平滑切换工作层区,自主平衡系统功率流动,有效维持直流母线电压稳定。

Field programmable gate array(FPGA)has the advantages of high data parallelism and high operating frequency,which can meet the needs of micro-second step precision simulation of power system,and shows great potential in the real-time simulation of the microgrid.For the further study of dynamic characteristics of photovoltaic(PV)and energy storage system(ESS)in the microgrid,the real-time simulation system of independent PV-ESS low-voltage DC microgrid is designed based on FPGA.Firstly,the real-time simulation framework of the DC microgrid is built,and a series of typical modules of the electrical system is designed.Secondly,considering the different dynamic requirements of real-time simulation,the PV-ESS control system model covering a variety of control strategies is built.Then,a hierarchical coordinated control strategy based on DC bus Signaling(DBS)is proposed,which balances the energy flow of the system by coordinating the control strategy of the PV-ESS converter.Finally,the FPGA real-time simulation results are compared with Simulink software.On the one hand,the accuracy and reliability of the FPGA real-time simulator are verified.On the other hand,it is also verified that the hierarchical coordination control strategy can smoothly switch the working layer,balance the power flow of the system,and effectively maintain the voltage stability of the DC bus.