Hardware-in-the-Loop testing allows the development and performance evaluation of a controller for a physical system in a realistic environment where the system under test is emulated in an accurate real-time simulation. The paper proposes the use of a computationally efficient, yet accurate approach for a real-time modeling of permanent magnet synchronous machines drive system. The proposed method is based on a synchronous reference frame approach where higher harmonics of the stator winding distribution and rotor magnet flux are fully represented up to a specified order. A procedure for extracting parameter from a set of Finite Element calculations is also reported. The real-time model is coded on a commercially available FPGA based platform. The proposed approach is verified on an interior permanent magnet synchronous motor designed for traction applications. Comparison of real-time implementation and experimental measurements on the actual motor are used to validate the proposed modeling.

This paper presents a methodology for analysing ac winding loss effects which can be significant when considering high-power density, high-efficiency and high-speed machine designs. A combination of finite element analysis (FEA) and experimental measurement has been employed to evaluate the components that contribute to the overall winding power loss. A number of conductor profiles and conductor arrangements have been investigated to give a more general insight into the ac winding phenomena. An experimental approach based on a partially wound stator is employed to allow different winding and conductor arrangements to be evaluated in a timely and accurate manner, as compared with numerical analysis or hardware tests on the complete machine assembly. The outcomes identify the temperature variation of ac winding loss, which can reduce with increasing temperature, and proposes an effective modelling and test method through which the effects can be quantified and experimentally verified.

An accuracy and robustness comparison is made between three high-frequency carrier-based sensorless control techniques. The high-frequency carrier signal may be injected on an arbitrary stationary three-phase axis or the estimated, synchronously rotating d or q-axis. Nonlinear distortion effects introduced by the pulse-width modulation switching process lead to distortion of the high-frequency carrier signal which causes a degradation of position detection accuracy. It is shown that all three signal injection techniques suffer loss of accuracy but the distortion is least when the carrier is injected on the torque producing q-axis. This leads to a tradeoff between the undesirable production of high-frequency torque ripple and the radiation of audible noise, and robustness to nonlinear distortion effects. To overcome this tradeoff a new compensation model is proposed. An experimental implementation of the new compensator is applied to the three signal injection techniques used to estimate the rotor angle of a permanent magnet ac machine. Experimental results confirm that the new compensator minimises the distortion of the high-frequency injection signal irrespective of its axis of injection which leads to an improvement in position estimation accuracy and robustness.

A new 'extended turn-off time' compensation parameter is introduced to overcome the low-current nonlinear voltage distortion effect in IGBT inverters. The compensation technique uses datasheet parameters in conjunction with an analytical approach to model the low-current switching characteristics of an IGBT. As a result, output voltage amplitude is accurately controlled and low-order voltage harmonics are reduced resulting in reduced current distortion, reduced power loss and, in motor drive applications, reduced torque ripple. The compensation technique can be easily integrated into a conventional 'average value' type compensator without the need for significant modification and without the need for experimentally intensive lookup tables.