High-Voltage Interlock Circuit Fault Detection Using Alternating Current Signals

The patent applies periodic action by using alternating current signals instead of direct current for detection. The detection signal alternates between positive and negative half-cycles, which helps distinguish genuine fault conditions from external interference. The controller generates periodic detection signals that flow through the high-voltage interlock circuit, and any deviation from the expected periodic pattern indicates a actual fault rather than interference.

The patent introduces an intermediary approach by using a current generator and detector as mediation components between the control devices and the high-voltage interlock circuit. These intermediary components generate standardized detection signals and process the responses, isolating the control logic from direct exposure to electrical interference while maintaining accurate fault detection capability.

The patent applies universality by designing the current generator and detector to serve multiple functions. The current generator not only generates detection signals but also adapts its output based on the detected impedance characteristics of the circuit. The detector simultaneously measures current flow and determines fault conditions. This multi-functionality reduces the need for separate specialized components for each function.

The detection system applies self-service by using the existing high-voltage interlock circuit itself as part of the detection path. The same circuit that needs to be monitored is used to carry the detection signals, eliminating the need for separate dedicated test circuits. The system monitors its own operational status through the normal current flow paths without requiring external test equipment.