Massively Parallel Implementation of AC Machine Models for FPGA-Based Real-Time Simulation of Electromagnetic Transients

This paper presents a generalized, parallel implementation methodology for real-time simulation of ac machine transients in an FPGA-based real-time simulator. The proposed method adopts nanosecond range simulation time-step and exploits the large response time of a rotating machine to: 1) eliminate the need for predictive-corrective action for the machine electrical and mechanical variables, 2) decouple the solution of the dq0 stator currents, and 3) enable the use of one-time-step delayed interface between the machine and the rest of the system which decouples the machine solution from that of the rest of the system. The proposed method simplifies the solution of the machine model without compromising accuracy or numerical stability of the simulation. This paper also presents a massively parallel, customized hardware architecture tailored to the solution of the mathematical model of ac machines. The proposed method and the developed hardware architecture are tested and verified based on the implementation of a permanent-magnet synchronous machine model and an induction machine-based ac-drive system in a field-programmable gate-array-based simulator. Real-time simulation is achieved with a computation time of 44 ns within the simulation timestep.