Abstract: For the purpose of researching and testing on the fault ride through capacity of distributed power generation system, a high-power grid simulator is proposed in this paper. This simulator can provide different types of fault simulating voltage. The main circuit adopts double PWM converter topology in order to realize the bidirectional power flow. Different operation modes, such as normal mode, step mode, low voltage ride through (LVRT) mode and harmonic mode etc., are designed in the software. The desired opertaion mode can be chosen by a simple interface. Instantaneous voltage and current double loop with feedforward voltage control strategy can track the reference voltage quickly. Experimental results about the prototype of the 1MW grid simulator verify the effectiveness and validity of the design.