Insulation fault detection systems and methods for insulation fault location for a redundant diode coupled DC power supply system

摘要

The invention relates to isolation fault detection systems and methods for insulation fault location for an ungrounded DC power supply system which is redundantly fed from a first diode coupled DC power source and a second diode coupled DC power source and to which a load is redundantly connected. Due to the diode coupling and the associated unbalanced current division of the load current arise in such a power supply system non-compensating partial currents in the leads and thus detectable by measuring current transformer differential current components that can interfere with the insulation fault finding a valid test current. To eliminate the interfering difference current components, primary-side compensation measures and indirect secondary-side compensation measures in an insulation fault location device are proposed in the measuring current transformers.