Realization of Electromechanical Transient and Electromagnetic Transient Real Time Hybrid Simulation in Power System

This paper presents a new interface approach in electromechanical transient and electromagnetic transient real time hybrid simulation in power system. The approach includes a parallel interface time sequence adaptable for real time hybrid simulation and an interface circuit adaptable for the parallel interface sequence. It also presents a new method to solve matrix asymmetry problem in electromagnetic transient simulation part caused by the connection of electromechanical network in hybrid simulation. Two cases are studied, modified IEEE 14 nodes system, and Dongbei-Huabei-Huazhong-Chuanyu interconnection system, an actual China power grid. The simulation results show that the hybrid simulation interface approach presented in the paper is valid and effective, and real time hybrid simulation for a 5000 nodes level electromechanical transient network and an electromagnetic transient network including 5 generators and more than 20 transmission lines is realized.

I. Introduction

Power Electromechanical transient procedure and electromagnetic transient procedure occur in power system when a fault or an operation happens. Usually we approximately analyze the two procedures individually, because uniform analysis is very complex and impractical. We use electromechanical transient simulation to analyze electromechanical transient procedure and electromagnetic transient simulation to analyze electromagnetic transient procedure. Electromechanical transient procedure varies much slowly compared with electromagnetic transient procedure, therefore the integration time step of electromechanical transient simulation is much larger than that of electromagnetic transient simulation. Usually the integration time step of electromechanical transient simulation is 10 milliseconds while that of electromagnetic transient simulation is about microseconds.