Design of a Power Hardware-in-the-Loop Test Bench for a Traction Permanent Magnet Synchronous Machine Drive

The challenges in inverter development for traction applications are low cost, better performance, optimized design and faster time to market. A solution is to use machine emulators whose phase currents and voltages at the terminal resembles a machine connected to a mechanical load for testing. Testing of an inverter for traction applications using permanent magnet synchronous machine (PMSM) emulator is presented. The emulator test bench consists of two identical front-to-front connected 2-level voltage source converters connected via an auxiliary inductor. Verification of the emulator is carried out in MATLAB/PLECS by comparing simulated phase currents, torque and rotor speeds to an equivalent PMSM drive. A common dc-link is used between the emulator and the inverter under test resulting into circulating common- mode currents. A common-mode choke and controller is used to eliminating common- mode currents. It is shown that the emulator can effectively emulate the PMSM drive with reasonable accuracy.