FAULT DETECTION METHOD FOR DETECTING LEAKAGE PATHS BETWEEN POWER SOURCES AND CHASSIS
First Claim
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;
a 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.
1 Assignment
0 Petitions
Accused Products
Abstract
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.
-
Citations
20 Claims
-
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; a 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. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. An electrical fault detection apparatus for an electrically powered vehicle or a hybrid-electrically powered vehicle wherein the vehicle comprises a direct current power system and an inherent capacitance between the direct current power system and the vehicle'"'"'s chassis, the apparatus comprising:
a fault detection module adapted for connection between a chassis ground of the vehicle and a first switch, the first switch connected to a positive node of the direct current power system, the fault detection module further adapted for connection between the chassis ground and a second switch, the second switch connected to a negative node of the direct current power system, the fault detection module comprising; a switch output driver control that provides switching signals for receipt by the first and second switches, the switching signals instruct the first switch and the second switch to sequentially open and close and thereby charge and discharge the inherent capacitance at predetermined intervals; a current sensor that senses a first current as the inherent capacitance is charged and a second current as the inherent capacitance is discharged; a controller connected to the switch output driver control, the controller provides a switch output driver control signal to the switch output driver control; a non-volatile memory connected to the controller, the non-volatile memory adapted for storing a plurality of instructions, wherein the plurality of instruction are configured to cause the controller to determine whether a fault condition exists based on digital measurement data output from the current sensor; and a communication interface connected to the controller that outputs a signal for a vehicle controller in response to a fault condition signal from the controller. - View Dependent Claims (11, 12, 13, 14, 15, 16)
-
17. A method of detecting a fault condition in a direct current power system of an electric or hybrid-electric vehicle, the direct current power system having an inherent capacitance between metal components of the direct current power system and the vehicle'"'"'s metal chassis, the method comprising:
-
sequentially opening and closing, using a digital controller, a first switch connected between a positive node of the direct current power system and a chassis ground and a second switch connected between a negative node of direct current power system and the chassis ground to charge and discharge the inherent capacitance at predetermined intervals; measuring a value of a first current as the inherent capacitance is charged and a value of a second current as the inherent capacitance is discharged; and calculating, using the digital controller, whether a ground fault condition exists in the vehicle using the measured values of the first current and second current. - View Dependent Claims (18, 19, 20)
-
Specification