DC link capacitance measurement for electric vehicle drivetrain
US9470739B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 12, 2013 |
| Grant date | Oct 18, 2016 |
| Priority date | — |
| Expiry date | Mar 3, 2035 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/7072
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
In order to detect deterioration of a DC link capacitor between a DC source and an inverter load in an electric propulsion vehicle, capacitance of the link capacitor must be accurately measured during in-service use. A charge is established on the link capacitor. The capacitor is isolated from the source and the inverter load. A constant current circuit is activated to discharge the capacitor. A first voltage is measured across the capacitor at a first time during the discharging. A second voltage is measured across the capacitor at a second time during the discharging. A discharge current flowing from the capacitor is measured during the discharging. The capacitance is calculated in response to the discharge current multiplied by a ratio of a difference between the second and first times to a difference between the first and second voltages. The calculated capacitance is monitored for a decline indicative of a failure.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.