Operating strategies for Switched Reluctance generators in exhaust gas energy recovery systems

The 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 analyse 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, non-linear modeling approach, combining magneto-static finite element analysis with time-domain circuit simulation. The results are compared with measurements performed on a SR generator designed for a prototype exhaust gas energy recovery system showing overall good agreement.