Parallel interaction protocol for electromagnetic and electromechanical hybrid simulation

A new hybrid simulator is presented, which comprises a transient stability (TS) simulator interfaced with an electromagnetic transients (EMT) simulator. It can simulate very large networks with TS simulator-like speed, while delivering EMT simulator-like accuracy on key components, while running in real time or in accelerated time modes. In the accelerated time mode, the simulator can be used as a system operation tool, offering extended contingency lists (such as mal-operation of power electronic devices) for dynamic security assessment. In real-time operation, the simulator can be interfaced with real control system hardware for detailed study, including the effects of waveform distortion and mal-operation of switching devices. Much of the development work in this area has been based on a serial communication protocol whereby each of the two different simulators runs in turn. However, a serial-protocol-based hybrid simulator cannot meet the real-time requirement of continuous operation of the EMT simulator. A parallel protocol is proposed, whereby both simulators run continuously, such that real-time operation is feasible. The feasibility of the proposed hybrid simulator is demonstrated by case studies, which show very good comparison between the parallel and series protocols, as well as with an EMTP benchmark.