DESIGN AND PERFORMANCE ANALYSIS OF THE PERMANENT MAGNET LINEAR REGENERATIVE SHOCK ABSORBER WITH FRACTIONAL-SLOT WINDING

This paper designs the permanent magnet linear regenerative shock absorber for a hub motor-driven micro electric vehicle.Considering the principle of minimizing cogging force and the influence of the slot structure on the magnetic field characteristics of the regenerative shock absorber, a 12-slot/14-pole fractional-slot winding was designed.The Carter factor was introduced to establish a mathematical model of the shock absorber, then to get the mathematical expressions for the induced electromotive force and electromagnetic damping force.Moreover, sinusoidal excitation was adopted to simulate road-induced vibration frequencies, amplitudes, and initial positions on the energy recovery characteristics.According to the simulation result analysis, higher induced electromotive force and recovered power output correspond with increasing vibration amplitude and frequency, and the initial phase of the shock absorber hardly affects the induced electromotive force and recovered power output.Finally, through tests on a dedicated dynamometer for the shock absorber by measuring induced electromotive force and electromagnetic damping force under different excitation speeds, the energy recovery potential of the designed shock absorber was verified and the electromagnetic damping force exhibits fluctuations.