A Versatile Power-Hardware-in-the-Loop-Based Emulator for Rapid Testing of Transportation Electric Drives

A power-hardware-in-the-loop (PHIL)-based mac- hine emulator system, which is essentially the power converters controlled to mimic machine behavior, can be used to test the traction drive inverter and drive controller prior to the development of an electric motor prototype. In this paper, a PHIL-based machine emulation system, which uses machine models based on lookup table data, generated from finite element analysis tools, is proposed. Using such machine models allows for the emulation of the machine’s magnetic (e.g., saturation) and geometric (e.g., cogging-torque) characteristics, greatly improving the emulation accuracy and utility. The proposed machine emulator system uses an inductive filter to interface the emulator and the driving inverter and a current control for the machine emulator. This allows for a simple practical realization of the machine emulator system. A detailed analysis of the machine emulator control to accurately emulate the machine model behavior is also presented here followed by the real-time simulation results validating the same. Experimental results are then obtained from the proposed emulator system and from a surface-mounted permanent magnet synchronous motor coupled to a dc dynamometer. These results are compared for various transient conditions, such as machine startup, speed reversal, and load change to validate the emulation accuracy.