Real-time simulation of finite-element analysis permanent magnet synchronous machine drives on a FPGA card

Abstract

This paper presents a real-time simulator of a permanent magnet synchronous motor (PMSM) drive based on a finite- element analysis (FEA) method and implemented on an FPGA card for HIL testing of motor drive controllers. The proposed PMSM model is a phase domain model with inductances and flux profiles computed from the JMAG-RT finite element analysis software. A 3-phase IGBT inverter drives the PMSM machine. Both models are implemented on an FPGA chip, with no VHDL coding, using the RT-LAB real-time simulation platform from Opal-RT and a Simulink blockset called Xilinx System Generator (XSG). The PMSM drive, along with an open-loop test source for the pulse width modulation, is coded for an FPGA card. The PMSM drive is completed with various encoder models (quadrature, Hall effects and resolver). The overall model compilation and simulation is entirely automated by RT-LAB. The drive is designed to run in a closed loop with a HIL-interfaced controller connected to the I/O of the real-time simulator. The PMSM drive model runs with an equivalent 10 nanosecond time step (100 MHz FPGA card) and has a latency of 300 ns (PMSM machine and inverter) with the exception of the FEA-computed inductance matrix routines which are updated in parallel on a CPU of the real-time simulator at a 40 us rate. The motor drive is directly connected to digital inputs and analog outputs with 1 microsecond settling time on the FPGA card and has a resulting total hardware-in-the-loop latency of 1.3 microseconds.