EPS System with PMSM - Pre-Circuit Design for Toshiba Drive

This design includes an ideal Permanent Magnet Synchronous Machine (PMSM) model, as well as a continuous D-Q controller and drive circuit. The mechanical load model includes static and kinetic friction, a steering force that varies with rack displacement, as well as various mass, inertia, damping and spring/stiffness elements of the steering system. The steering torque, applied by the vehicle's driver, is assisted by torque from the motor scaled by the gear ratio. For the control, the first gain/pole-zero block (far left) specifies the amount of "torque_assist" gain (assist torque as a multiple of the vehicle operator's torque applied to the steering wheel), as well as providing compensation to improve system stability.

Note that this is a "tunable" design. Many of these system parameters can be changed by the user. Then a new simulation can be run and the updated results can be observed in the waveform viewers.

A companion design, "EPS System with PMSM Motor and Toshiba SSM3K33R Power MOSFET", uses a sampled-data D-Q control algorithm and space-vector modulation (SVM) to control Toshiba SSM3K333R Power MOSFET switches in a switching inverter circuit. That design forcuses on the performance and temperature monitoring of those switches.

Mike Donnelly's picture



Mike Donnelly

Joined November 8, 2013
Design added Saturday, March 23, 2019 | 1:00 pm PDT