Fault detection system for electric automobile traction system having floating ground
US5561380A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 8, 1995 |
| Grant date | Oct 1, 1996 |
| Priority date | — |
| Expiry date | May 8, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R31/007
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A fault detection system detects the existence of unwanted electrical paths between the high voltage traction system of an electric car and the chassis of the car. The fault detection system includes a positive sampling RC circuit connected to the positive conductor of the traction system and a negative sampling RC circuit connected to the negative conductor of the traction system. Each RC circuit generates a voltage, and the voltages are balanced, i.e., the voltages are equal and opposite, when no leakage path exists. In contrast, when a leakage path to chassis exists, the voltages are not balanced. A comparator compares the sum of the voltages to a setpoint which varies proportionately to the varying voltage of the battery of the traction system, and a fault condition is indicated when the sum of the voltages exceeds the setpoint.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.