Ground fault detector

摘要

A ground fault detector which does not need complicated circuitry and can detect a ground fault with high accuracy in conformity to a capacitance of a common mode capacitor is presented. Upon judging the ground fault on the basis of a threshold for a high-tension power supply system which is electrically isolated and mounted in a vehicle, a controller in a ground fault detector alters the threshold in conformity to a capacitance of a common mode capacitor of which value is different between a first state that a system main relay is ON and a second state that the system main relay is OFF, thereby judges the ground fault on the basis of the altered threshold. Thus the ground fault detector can adequately detect the ground fault in conformity to the capacitance of the common mode capacitor. Thus the detector can detect the ground fault with accuracy without complicated circuitry.

主权项

1. A ground fault detection system for judging a ground fault, on the basis of a threshold for judging a ground fault, for a high-tension power supply system which is mounted in a vehicle in an electrically insulated state, the ground fault detection system including:
a judging means to alter the threshold on the basis of a state of the vehicle and judge the ground fault on the basis of the altered threshold; and a plurality of vehicle equipment which are connected to the high tension power supply system, wherein: each of the plurality of vehicle equipment and the judging means is mutually connected so as to communicate; each of the plurality of vehicle equipment is configured to store a value of capacitance of its common mode capacitor as the state of the vehicle and to transmit the value of capacitance of its common mode capacitor to the judging means; and the judging means alters the threshold in conformity to the value of the capacitance of the common mode capacitor received from each of the plurality of vehicle equipment.