Variable frequency drive system apparatus and method for reduced ground leakage current and transistor protection

Abstract From the Canadian patent

As applications of variable frequency drives (VFD) (50) continue to grow so do challenges to provide VFD(50) systems meeting application specific requirements . For multiple reasons to include safety standards and electromagnetic interference, reduced ground leakage current is desireable. Building high ouput voltage VFDs (50) using transitors rated at voltages lower than the VFD ouput votlage is desireable for economic resons. The apparatus and method described herein meet these challenges and others in part by , placing an electrically insulating plaste (cpl76) having high thermal conductivity , a low dielectric constant and high dielectric strenght between , the heat sink plate of …