Switch mode converter based high performance power-hardware-in-the-loop grid emulator

This paper presents a power-hardware-in-the-loop (PHiL) grid emulator (GE) which is based on switch-mode voltage source inverters (VSI) with the magnetic coupling. The grid emulator is controlled to reproduce the typical grid fault behaviors (under-voltage, interruption, frequency variation, fault-ride-through etc.) for the equipment under test (EUT). In past several different commercial grid emulators were coming out one after the other, and recently the switching mode voltage source inverter is getting more and more attention as an alternative PHiL grid emulator. Most of commercial GEs have a satisfied performance of the typical grid steady and transient emulation. However, these products mainly have a very limited bandwidth and lower dynamic response. Therefore, this project investigates a new topology of the VSI inverters by using the magnetic coupling. And the final PHiL system performs high power capability and high dynamic response at same time. A down-scaled 5kVA prototype of proposed grid emulator was implemented. A RL-load bank and a rectifier-load are used to represent the two different types of EUT. The obtained experimental results shows the feasibility of the PHiL grid emulator.