Patent ID: 6552598
Filing Date: 2003-04-22
Classification: H03K

Abstract:
A semiconductor high voltage electrical energy transmission switching system including a multiple stack of free floating power semiconductor thyristor circuit sections having separate input and output terminals respectively with each of said circuit sections being isolated from ground potential and arranged in tandem with the output terminals of one circuit section connected to the input terminals of an adjacent circuit section for distributing auxiliary electrical power sequentially through each of said circuit sections, with each section in the stack comprising: a plurality of SCR switching thyristors connected in series between the input and output terminals of the respective circuit section, with each SCR having a gate terminal, and further comprising gating means connected to the gate terminal of each SCR, isolation means including a transformer having a first and second winding for interconnecting the input and output terminals of one circuit section to the respective output and input terminals in each adjacent circuit section of the multiple stack such that the voltage difference between said first and second transformer winding is equal to no more than the maximum voltage across said circuit section, a power supply connected to said isolation means and a gate drive circuit for controlling the firing of said SCR switching thyristors in said circuit section through said gating means wherein the gate drive circuit is tied to an intermediate voltage point within said circuit section in common with said gating means and said power supply.