초록 ▼

A method of detecting a ground fault condition between a direct current power system and the chassis ground of an electric or hybrid-electric vehicle is provided. The method includes sequentially opening and closing a first switch connected between a positive node of the direct current power system

A method of detecting a ground fault condition between a direct current power system and the chassis ground of an electric or hybrid-electric vehicle is provided. The method includes sequentially opening and closing a first switch connected between a positive node of the direct current power system and the chassis ground of the vehicle and a second switch connected between a negative node of direct current power system and the chassis ground. The sequential opening and closing of the first and second switches charges and discharges an inherent capacitance present between the metal components of the direct current power system and the chassis. First and second currents are created as the inherent capacitance is charged and discharged. Measurements of the created first and second currents are then used to determine whether a ground fault condition exists between the direct current power system and the vehicle chassis ground.

대표청구항 ▼

What is claimed is: 1. An apparatus for monitoring a direct current system for ground faults in a device having an inherent capacitance between the direct current system and a chassis ground, the apparatus comprising:a fault detection module;a first switch connected between a positive node of the di

What is claimed is: 1. An apparatus for monitoring a direct current system for ground faults in a device having an inherent capacitance between the direct current system and a chassis ground, the apparatus comprising:a fault detection module;a first switch connected between a positive node of the direct current system and the fault detection module;a second switch connected between a negative node of the direct current system the fault detection module;a switch driver that sequentially opens and closes the first switch and the second switch such that the inherent capacitance is charged and discharged;wherein the fault detection module is connected between the chassis ground and the first and second switches, the fault detection module comprising:a controller for controlling the switch driver;a current sensor connected to the controller, the current sensor senses a first current when the first switch is closed and a second current when the second switch is closed, the current sensor provides current measurements, wherein the current measurements are signals indicative of the amperage of each of the first current and the second current; the current sensor comprises a programmable gain amplifier and an analog to digital signal converter, the programmable gain amplifier is adapted to transmit a signal to the analog to digital signal converter, and the analog to digital signal converter is adapted to transmit a current measurement to the controller; anda data interface connected to the controller, the data interface outputs a signal in response to a result provided from a controller calculation, wherein the controller calculation comprises current measurements.