For the realization of real-time simulation of power system with distributed generations

this paper studies a multi-rate real-time simulation method based on the real-time digital system(RTDS)and field programmable gate array(FPGA)co-simulation platform. The power network is divided by the partial latency insertion method

and multi-rate interaction of interface electric parameters is implemented by the fitting method and the extrapolation method. In order to reduce the influence of communication delay on simulation accuracy

a method of asynchronous interaction of interface electric parameters which enables FPGA's data to be transmitted prior to RTDS's data is proposed. An IEEE-5 power system containing two photovoltaic generations is simulated in real-time on the RTDS and FPGA co-simulation platform with a 50 μs/1 μs hybrid simulation step

the result of which is compared with the simulation data of PSCAD platform

and the feasibility of the proposed co-simulation platform and accuracy of the real-time simulation method are verified. This work is supported by National Natural Science Foundation of China(No. 51477114)and Science and Technology Planning Project of Tianjin(No. 13TXSYJC40400).