Real-Time FPGA-RTDS Co-Simulator for Power Systems

This paper proposes a co-simulation platform using field-programmable gate array (FPGA) and real-time digital simulator (RTDS) for the simulation of large power systems. It combines the advantages of high computational power from FPGA and better modelling flexibility from RTDS together. The FPGA therefore acts as an efficient and economical extension to RTDS especially when simulating large ac systems. One of the significant advantages of the proposed co-simulator is that it avoids the potential interface error existing in the conventional approach of interfacing transient stability program with electromagnetic transient programs. Two key aspects of the proposed co-simulator are discussed: 1) the interface design between FPGA and RTDS and 2) the hardware implementation and expandability of the platform. Two case studies are presented to verify the simulation accuracy and capability of the proposed co-simulator. The first case simulates a two-area four-machine power system with one area simulated in FPGA and the other area in RTDS. Comparisons are made with the case where the complete system is simulated in RTDS. The second case simulates a system of 141 buses in FPGA to demonstrate the simulator’s capability in simulating large power systems.