Operating Strategies of Switched Reluctance Machines for Exhaust Gas Energy Recovery Systems

This paper presents an operating strategy for high-speed switched reluctance (SR) generators employed in exhaust gas energy recovery systems. The machine is operated in “single pulse” mode, and a parametric study of the control angles is performed to analyze the machine operation. It is shown that, for given speed and power, optimum sets of control angles exist, which achieve maximum machine efficiency and minimum thermal stress. This study is undertaken using a coupled nonlinear modeling approach, combining magnetostatic finite-element analysis with time-domain circuit simulation. The results are compared with measurements performed on an SR generator designed for a prototype exhaust gas energy recovery system, showing overall good agreement.