Sensorless control at high starting torque of a 4000 Nm traction drive with permanent magnet synchronous machine

This paper presents numerical torque simulations and sensorless control of a permanent magnet synchronous machine (PMSM). The machine was developed for a wheel-hub traction drive with a maximum torque of 4000 Nm. The Indirect Flux detection by Online Reactance Measurement (INFORM) method provides control at standstill and low speed without a rotor position sensor. A back electromotive force (EMF) model handles the operation at higher speed. The structure of the control and the load behaviour of INFORM are shown. The torque characteristic is calculated by numerical simulation and compared with recorded values. An additional curve depicts the influence of the INFORM test signals on machine torque.