Title:
DIRECT CURRENT ISLANDING DETECTION METHOD BASED ON POSITIVE FEEDBACK OF BUS VOLTAGE HAVING SPECIFIC FREQUENCY
Document Type and Number:
WIPO Patent Application WO/2021/000682
Kind Code:
A1
Abstract:
A direct current (DC) islanding detection method based on positive feedback of a bus voltage having a specific frequency, which is mainly composed of three parts, comprising: a bus voltage specific frequency component extraction link, a specific frequency amount of disturbance injection link, and a DC islanding determination link. The bus voltage specific frequency component extraction link and the specific frequency amount of disturbance injection link constitute a positive feedback mechanism in a control loop of a power management unit; in a grid-connected mode of a DC grid, the positive feedback mechanism is rendered ineffective due to the control effect of the power management unit on a bus, and the bus voltage is maintained to be stable; in an islanding mode of the DC grid, the power management unit enables the bus voltage to self-oscillate at a specific frequency under the action of the positive feedback mechanism; and the DC islanding determination link determines whether a system is in islanding mode according to the trend of change and magnitude of a bus voltage component at the specific frequency. The present method may quickly detect the occurrence of DC islanding, and may eliminate blind spots of detection in a passive islanding method.
Inventors:
LI WUHUA (CN)
HUANG QINGHUI (CN)
LI CHUSHAN (CN)
YANG HEYA (CN)
GU XIAOWEI (CN)
CHEN MIN (CN)
YANG HUAN (CN)
HE XIANGNING (CN)
HUANG QINGHUI (CN)
LI CHUSHAN (CN)
YANG HEYA (CN)
GU XIAOWEI (CN)
CHEN MIN (CN)
YANG HUAN (CN)
HE XIANGNING (CN)
Application Number:
PCT/CN2020/093795
Publication Date:
January 07, 2021
Filing Date:
June 01, 2020
Export Citation:
Assignee:
UNIV ZHEJIANG (CN)
International Classes:
G01R31/08
Foreign References:
| CN110376483A | 2019-10-25 | |||
| KR20110070023A | 2011-06-24 | |||
| CN102262182A | 2011-11-30 | |||
| CN105467237A | 2016-04-06 | |||
| CN104569685A | 2015-04-29 | |||
| CN102830312A | 2012-12-19 |
Attorney, Agent or Firm:
HANGZHOU TIANHAO PATENT AGENCY CO., LTD. (CN)
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