DC bus boost method and system for regenerative brake

A system, comprising:

• a controller configured to control an electric motor;
• a rectifier comprising a positive solid state switch and a negative solid state switch for each of three input phases of alternating current power, the rectifier configured to convert three input phases of alternating current power to direct current power applied to a direct current bus;
• and,
• a detector configured to detect the voltage of the direct current bus, and the voltage of each input phase;
• wherein the controller is configured to perform the steps of:
• (a) using the detector to detect the voltage of the direct current bus, and the voltage of each phase of input power;
• (b) identifying the input phase having the highest voltage, and cycling the positive and negative solid state switches of the rectifier at the identified phase;
• and
• (c) placing a solid state switch of the rectifier for the two other phases in a conducting state based upon which other phase exhibits the greater voltage difference from the identified phase.

A method for controlling an electric motor via a controller and a rectifier comprising a positive and a negative solid state switch for each of three phases of power, the rectifier converting three input phases of alternating current power to direct current power applied to a direct current bus, the method comprising:

• (a) detecting the voltage of the direct current bus, and the voltage of each input phase of input power;
• (b) identifying the phase of input power having the highest voltage, and cycling the positive and negative solid state switches of an identified phase;
• and
• (c) placing a solid state switch for the two other phases in a conducting state based upon which other phase exhibits the greater voltage difference from the identified phase;
• (d) determining a duty cycle for cycling the positive and negative solid state switches of the identified phase based on electric power requirements, and wherein the positive and negative solid state switches of the identified phase are cycled at the determined duty cycle.