Patent ID: 8570774
Filing Date: 2013-10-29
Classification: H02M

Abstract:
1. An electrical power system for providing direct current (DC) power to an electrical load, comprising: an alternating current (AC) power source configured to output an AC signal; a single phase pulse-width modulated (PWM) rectifier coupled to said AC power source and to said electrical load, said PWM rectifier being configured to receive said AC signal from said AC power source and to rectify said AC signal into a DC signal configured to operate said electrical load, wherein said DC signal includes a ripple component having a ripple energy; a DC link capacitor coupled in parallel to said load and said PWM rectifier; and an active ripple energy storage circuit having a first terminal, a second terminal and a third terminal, said active ripple energy storage circuit being coupled in parallel to said electrical load, said PWM rectifier and said DC link capacitor via said first terminal and said second terminal, said third terminal being coupled to said second terminal, said active ripple energy storage circuit being structured to selectively absorb and discharge at least part of said ripple energy, wherein said active ripple energy storage circuit includes an auxiliary storage system configured to store said at least part of said ripple energy; wherein said auxiliary storage system operates over a wider voltage range than the DC link capacitor; and wherein the active ripple energy storage circuit is configured to allow a reduced size of the DC link capacitor relative to a system not having the active ripple energy storage circuit.