Brushless dc motor controller with speed control from zero to above base speed

摘要

A permanent magnet brushless DC motor controller, and method of operation of the controller, provide effective and smooth regulation of the speed of the motor from zero to above base speed (e.g. at least about 100% above base speed). For a three phase motor the controller comprises three Hall sensors, a power amplifier comprising a plurality of power electronic switch connected to the motor, two switches (bottom and top) for each phase, and at least an eight bit microprocessor connected to and controlling the switches, and a frequency to voltage controller. The Hall sensors are connected substantially directly to the microprocessor, and also through the frequency to voltage converter. In response to sensing by the Hall sensors, both directly and through the frequency to voltage converter, the microprocessor is used to control the electronic switches to smoothly speed regulate the motor both below and above base speed. Below base speed the microprocessor utilizes a commutation truth table, and the bottom switches provide pulse width modulation, whereas equal to and above base speed the microprocessor uses first and second jump tables, the first jump table comprising the commutation truth table forward rotated one step, and the second jump table the commutation truth table forward rotated two steps.