P.H. Mellor

An automated calorimetric method of loss measurement in electrical machines

Abstract Traditionally the losses dissipated in an electrical machine have been determined from the difference between the measured input and output powers. However, the achievable accuracy is limited by the uncertainty of measurement errors, particularly if the machine is supplied with distorted voltage and current waveforms. Therefore, a more appropriate approach is to employ a calorimetric method in which the losses are determined by direct measurement of the dissipated heat. This paper describes the control and instrumentation of such an automated calorimetric system which has been commissioned to accomodate machines of up to 75 kW rating, and in which losses can be measured to an accuracy better than 10 W.

Comparison of control methods for electric vehicle antilock braking / traction control systems

The alleviation of environmental problems associated with personal, public and commercial transport in urban areas has become an important issue for both policy makers and the automotive industry. Future legislation in Europe and the USA is expected to introduce strict limits in vehicle emissions, and both electric and hybrid vehicles are considered to be strong contenders for meeting low / zero emissions targets. As a result, research into electrically driven powertrains, which have similar performance attributes as ICE (Internal Combustion Engine) vehicles, has led to the development of electrically actuated wheel technologies, with increasing attention being focused on research into novel antilock braking / traction control (ABS / TCS) strategies.

Effect of high frequency flux ripple on iron loss in induction machines

Abstract The effect of the load on the iron loss in induction machines is usually neglected. However, the component of loss associated with high frequency flux ripples caused by stator and rotor slotting and mmf harmonics varies significantly with load, and can account for a substantial portion of the total iron loss. This is confirmed by theoretical and experimental studies on a 37 kW, 4-pole machine.