FPGA-based Ultra-Low Latency HIL Fault Testing of a Permanent Magnet Motor Drive using RT-LAB-XSG

Abstract

Presented is a real-time simulator of a permanent magnet synchronous motor (PMSM) drive implemented on an FPGA card. Real-time simulation of PMSM drives enables thorough testing of control strategies and software protection routines and therefore allows rapid deployment of vehicular or industrial applications. The proposed PMSM model is a phase domain model with sinusoidal flux induction. A 3-phase IGBT inverter drives the PMSM machine. Both models are implemented on an FPGA chip, without any VHDL coding, with the RT-LAB real-time simulation platform of Opal-RT Technologies using a Simulink blockset called Xilinx System Generator (XSG). The paper explains various aspects of the design of the motor drive models in fixed-point representation in XSG, as well as simulation validation against a standard PMSM drive model built in Simulink. The PMSM drive, along with a open-loop test source for the pulse width modulation, is coded for an FPGA card. The model has user-selectable dead time, modulation index, source angle offset, and frequency. 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 can also run in a closed loop with a controller executing on a CPU of a real-time simulator. The phase-domain PMSM drive model runs with an equivalent 10 nanosecond time step (100 MHz FPGA card) and has a latency of 300 nanoseconds (PMSM machine and inverter). 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.