Power hardware-in-the-loop (PHIL) based machine emulation is increasingly being recognized as an effective approach for simplifying the testing of electric drive systems. In machine emulation, a power electronic converter emulates the behavior of an electric machine. Since the motor is being emulated, several motor types/ratings, and its corresponding impact on the driving inverter and drive inverter controller can be studied before the actual motor is prototyped (developed). Furthermore, since the machine behavior is emulated, a dynamometer is not required to load the machine and operate it at it's required torque/speed. These two factors, reduce the time to market of the complete drive system significantly, when machine emulation is used. In addition, a machine emulator can also be used to study the response of the driving inverter and it's controller for several transient conditions which are typically avoided when testing on a physical machine, due to fear of equipment damage.

A PHIL based machine emulation is relatively a new technology and therefore there are several open research problems to address. Emulation accuracy is significantly dependent on the details of the machine model used for emulation. Another important research concern is the control strategy for the machine emulator and its interaction with the driving inverter controller.  It is necessary to ensure that the machine model detail is not compromised while developing a control strategy for the machine emulator. Validating the developed emulator system for a wide variety of transient drive behavior such as faults, emulation of different machine topologies, etc. is also another important research problem to address.

This PhD research work develops a PHIL based machine emulator system, which uses machine models based on look-up table data, generated from finite element analysis (FEA) tools. The usage of these machine models allows for the emulation of the machine`s magnetic (eg. saturation) and geometric (eg. cogging-torque) characteristics, thus greatly improving the emulation accuracy and utility. This PhD research work also develops a control strategy for the machine emulator. The interaction of the emulator control strategy in relation with the driving inverter control strategy is studied and considerations to ensure stable and accurate emulation are proposed. The proposed control strategy developed for the emulator also takes into account the electric drive system transient behavior during the event of driving inverter faults. Experimental setups of the developed emulator systems are used to emulate the behavior of a permanent magnet synchronous machine (PMSM), a variable-flux machine (VFM), an open-winding PM machine. The results obtained from the emulator system are compared with that obtained from a driving inverter feeding a prototype machine to validate the utility and accuracy of the developed emulator systems.