Abstract: Switching losses are distributed equally between multiple switching devices in a rectifier bridge (50) in which the rectifier bridge comprises at least a first pair of serially connected switching devices (56A, 56B) connected between positive and negative DC output buses (52, 54) and a second pair of serially connected switching devices (58A, 58B) connected in parallel with the first pair of switching devices. Only one of the switching devices in each pair of switching devices is pulse width modulated at any time at a frequency substantially higher than a frequency of the AC power applied to the rectifier bridge while another of the switching devices in each pair of switching devices is operated in synchronism with the waveform of the AC power applied to the bridge. Operation further involves periodically alternating the PWM operation of the switching devices between switching devices in each pair of switching devices so as to distribute the losses.
Type:
Grant
Filed:
April 21, 1997
Date of Patent:
June 13, 2000
Assignee:
General Electric Company
Inventors:
Ajith Kuttannair Kumar, Allen Barr Plunkett