Optimal PWM method for electric and electro-hydraulic power steering applications

This paper presents a methodology for choosing the optimal PWM method for the 3-phase automotive drives applications for electric and electro-hydraulic power steering. It shows how some of the automotive specific requirements transpose to PWM requirements. A system overview with motor and control principles has been presented, followed by the method of power loss calculations based on datasheet parameters and, after that, an overview of the PWM Methods is given. These Methods are compared based on: power loss minimisation, usage of the battery voltage, quality of output current and noise emission minimisation.