Patent ID: 7157807
Filing Date: 2007-01-02
Classification: H02M

Abstract:
1. A rectifier circuit for powering three power conversion modules using a three phase AC input without a neutral connection, said rectifier circuit comprising: a first bridge rectifier that is connected to a first phase of said three phase AC input, that has a first DC output that produces a first rectified waveform; a second bridge rectifier that is connected to a second phase of said three phase AC input, that has a second DC output that produces a second rectified waveform; a third bridge rectifier that is connected to a third phase of said three phase AC input, that has a third DC output that produces a third rectified waveform; a connection between said first, second, and third bridge rectifiers that forms a virtual neutral; and a first protection circuit that is connected to at least one of said first, second and third DC outputs, the first protection circuit further having a transistor having a gate and an emitter; a silicon controlled rectifier (SCR) having a gate, a first end connected to said gate of said transistor, and a second end connected said emitter; and a zener diode having a first end and a second end, said first end being in communication with said rectified waveform of said at least one of said first, second and third DC outputs and said second end being connected to said gate of said silicon controlled rectifier, wherein said transistor selectively opens its respective DC output to prevent overvoltage when at least one of said first, second and third DC outputs is shorted.