A Real-Time Simulation Model With Constant Admittance Matrix for Multiple Grid-Connected Converters System

Real-time simulation (RTS) is indispensable for validating multiple grid-connected converter systems that form the backbone of renewable energy stations. In this article, an RTS model for multiple grid-connected converters system is proposed by utilizing a half-step prediction-correction method. This model ensures a constant admittance matrix and facilitates delay-free decoupling of the converters. Furthermore, a hardware solution engine and implementation method using the field programmable gate array (FPGA) are developed for multiple converters system. Finally, the high accuracy and validity of the proposed model (PM) are validated through offline simulation, a physical prototype, and an FPGA-based RTS platform. The FPGA-based simulation results demonstrate that the PM can achieve RTS with 500-ns (minimum up to 80-ns) time-step for a radial multiconverter system comprising 130 converters (780 switching devices). For a trunk multiconverter system consisting of 11 converters (66 switching devices), the model can also achieve 500-ns (50 clock cycles) RTS. Compared with RT-LAB simulator, existing methods, and nodal analysis method, it exhibits certain advantages in terms of simulation scale, hardware resource usage and time-step.