An auxiliary power supply equipment for a high voltage installation includes a power source at ground potential, a load circuit at high potential, and a transmission link for coupling the power source to the load circuit. The power source includes a high frequency voltage generator, and the transmission link comprises a first and a second current path. Each path is closed by capacitive coupling to provide insulation between the ground potential and the high potential, and each current path has a reactive compensation means for series compensation of reactive power generated by the capacitive coupling.