Methods and apparatus for controlling brushless motors

摘要

A method or apparatus for controlling a brushless motor having an inverter. The inverter comprises a first and a second plurality of switching elements at a first and second phase sides, respectively, and a drive control device. The drive control device switches either a state of the first or the second plurality of switching elements. A first transient voltage is generated in each second switching element when the state of the second plurality of switching elements is switched. The second transient voltage is generated in each first switching element when the state of the first plurality of switching element is switched. Timing of switching the state of the first plurality of switching elements by the PWM control is altered, such that a combined voltage of the first and the second transient voltage is less than a maximum allowable voltage of the first plurality of switching element or of the second plurality of switching elements.