Method for electroless sensorless control of electric motor of auxiliary or external power steering system of motor car, involves calculating voltages in system for computation of currents, from terminal voltages

摘要

The method involves computing currents (508, 509) in a rotor-field-oriented coordinate system. Voltages (502, 503) used in a rotor-field-oriented coordinate system for computation of the currents are calculated from motor terminal voltages (505) based on a pulse-width modulation (PWM) inverter (516). The motor terminal voltages are computed from intermediate circuit voltage of the inverter. An actual PWM period is determined at a departure of a half-bridge to ground. The PWM is determined at output of the PWM inverter.