Development of a new coupling method for analog-digital hybrid real-time power system simulator

This paper proposes a FPGA-based hybrid real-time simulator (HRTS) utilizing a new coupling method for an analog-digital interface. The proposed method is called “current-current coupling method”. By means of the proposed method, current flows in the digital simulator are represented with a current source in the analog simulator, and current flows in the analog simulator are represented with a virtual current source in the digital simulator. The current-current coupling method is effective to reduce the influence of the delay time of the analog-digital interface. In order to verify the effectiveness of our proposed method, the digital model of a synchronous generator is configured into a Field-Programmable Gate Array (FPGA) and is connected to the simply simulated power system in the analog simulator. The stability of the proposed coupling method and the accuracy of the transient simulation of the synchronous generator can be demonstrated.