Real-time co-simulation for voltage source converter closed-loop control

In order to solve the problems of the conflict between computational efficiency and simulation precision, as well as a large amount of calculation in real-time simulation of voltage source converter closed-loop control, we put forward a co-simulation design scheme for the power electronic real-time based on FPGA+DSP+PC architecture. The design scheme provides a multi-rate simulation platform for power electronic system. In the platform, we adopt a continuous-discontinuous model separation method to segment VSC model and extract the parameters, combine switching-function approach with state-space approach to design the float point solver, and use a system rapid prototyping method to build a simulation system model. A three-phase two-level closed-loop control system case is selected for real-time multi-rate simulation test. The FPGA calculates inverter with 500 ns simulation step and the DSP simulates closed-loop control part with 2 μs. The results show that the real-time co-simulation is 233 times faster than the multi-rate off-line simulation, 991 times faster than the single rate off-line simulation, and the Euclidean norm is 1%, significantly improving the simulation precision and calculation efficiency. And the system rapid prototyping method using automatic code generation technology can obviously shorten the development cycle.