Title:
METHOD FOR DETECTING AN ISOLATION FAULT
Document Type and Number:
WIPO Patent Application WO/2020/029901
Kind Code:
A1
Abstract:
The present disclosure relates to a method for detecting an isolation fault in an isolation resistance (17, 18) between a positive and negative high-voltage bus rail (5, 6) and a vehicle chassis (12) on a high-voltage propulsion side (3) of a high-voltage system of an electric or hybrid-electric vehicle. The high-voltage system is split into a high-voltage battery side (1) and the high-voltage propulsion side (3) by means of first and second high-voltage contactors (7, 8) located in the positive and negative high-voltage bus rails (5, 6), respectively. The high-voltage propulsion side (3) comprises first and second capacitors (9, 10) connected in series across the positive and negative high-voltage bus rails (5, 6), wherein a common junction (11) of the first and second capacitors (9, 10) is connected to the chassis (12). The method comprises: ensuring that first and second high-voltage contactors (7, 8) are set in an open state; operating an isolated DC/DC converter (13) for converting a supplied high-voltage (14) from a high-voltage battery (2) of the high-voltage battery side (1) to a low-voltage output (15) on the high-voltage propulsion side (3); supplying the low-voltage output (15) to the positive and negative high-voltage bus rails (5, 6) for simultaneous charging of the first and second capacitors (9, 10); registering a charging current, voltage level or energy level of the first and second capacitors (9, 10); and determining, based in the registered charging current, voltage level or energy level of the first and second capacitors (9, 10), whether an isolation fault between the positive and/or negative high-voltage bus rail (5, 6) and the vehicle chassis (12) on the high-voltage propulsion side (3) of the high-voltage system is present. The present disclosure also relates to a corresponding high-voltage circuit of an electric or hybrid-electric vehicle.
Inventors:
ISAKSSON BJÖRN (SE)
Application Number:
PCT/CN2019/099193
Publication Date:
February 13, 2020
Filing Date:
August 05, 2019
Export Citation:
Assignee:
NINGBO GEELY AUTOMOBILE RES & DEVELOPMENT CO LTD (CN)
International Classes:
G01R31/02
Foreign References:
| US20150022217A1 | 2015-01-22 | |||
| CN104423377A | 2015-03-18 | |||
| CN102193066A | 2011-09-21 | |||
| US9263948B1 | 2016-02-16 | |||
| US20110175619A1 | 2011-07-21 | |||
| EP2869075A1 | 2015-05-06 |
Attorney, Agent or Firm:
KING & WOOD MALLESONS (CN)
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