LINE-TO-GROUND FAULT DETECTOR, CHARGER FOR ELECTRIC VEHICLES, AND METHOD OF DETECTING LINE-TO-GROUND FAULT

摘要

PPROBLEM TO BE SOLVED: To provide a charger for an electric vehicle that quickly detects a line-to-ground fault and besides is more reliable. PSOLUTION: The line-to-ground fault detector 102 of a charger 100 for electric vehicles has a series circuit 1021 composed of two resistors 1021A and 1021B with equal resistance values which are connected to lines 103A and 103B for charge on the sides of a positive electrode and a negative electrode, a grounding wire 1023 which connects a grounding connection point 1021C of wiring for connecting the resistors 1021A and 1021B with each other to an earth (the ground) 400, a current detector 1022 which outputs the measured values of a DC current flowing in the grounding wire 1023 successively, and a controller 1024 into which the measured values of the current detector 1022 are input. In quick charge of the on-board battery 202 of an electric vehicle 200, the current detector 1022 measures the DC currents flowing in the grounding wire 1023 successively, and the controller 1024 detects the line-to-ground fault by comparison between the actually measured current values output successively by the current detector 1022 and a threshold. PCOPYRIGHT: (C)2011,JPO&INPIT