Waveform separator apparatus and method for detecting leakage current in high voltage direct current power systems

A waveform separator system for determining DC leakage current flowing through an insulating structure in a high voltage direct current power system, wherein the DC leakage current is a composite DC current comprising one or more high magnitude momentary spikes, and having a DC component and an AC component includes: (1 ) a waveform separator configured to receive the composite DC current flowing through the insulating structure and to separate the composite DC current into corresponding direct current (DC) and alternating current (AC) components wherein the AC component has a first rate of change, and wherein the DC component has a second rate of change, and wherein the first rate of change is greater than the second rate of change; (2) at least one comparator configured to receive the AC component and produce at least one corresponding digital signal; and (3) a processor configured to: (a) receive the at least one corresponding digital signal and the DC component, (b) analyze the at least one corresponding digital signal and the DC component, and; (c) determine a resultant leakage current flowing through the insulating structure.