State Grid Corporation of China

Xj Group Corporation

Xj Electric Co., Ltd

Xuchang Xj Software Technologies Ltd

Jiangsu Electric Power Company Research Institute

Junhong Qiu

Meng Li

Huawei Jia

Xing Liu

Lei Gao

Xintao Dong

Ruizhi Jiang

Lunshan Zhang

Yongjian Tao

Juan Ji

Bao Zhao

Jingwan Liang

Feng Li

Yake Xi

Xinling Li

Qiang Niu

Yongxin Liu

Shuai Jiang

Leitao Wang

Zhen Li

Lintao Ma

The invention relates to a method of differential protection in the power distribution networks based on phase difference principles. The method comprises the following steps: collecting the current and voltage signals of each loading switch; calculating phase difference between the corresponding currents at two adjacent loading switches, wherein at least one of the two adjacent loading switches accords with &#x394;I&#x3e;n&#xb7;&#x394;I+&#x394;I; tripping the two adjacent loading switches if the phase difference corresponding to the two adjacent loading switches being greater than a threshold then a section between the two adjacent loading switches being determined as a fault section. The method only needs to calculate the phase difference between the corresponding currents at the two adjacent loading switches, and achieves the fault determination according to the phase difference being greater than the threshold. The method has low data synchronizing requirements, and processes the fault determination according to the collected signals. The time required for the entirely determining process is short, and a fast protecting response is achieved, thus the problem of slowly protecting response in the existing relay-protection method for the power distribution networks is solved.

Method of differential protection in the power distribution networks based on phase difference principles

The present invention relates to a method of preventing misoperation about a relay protection device in a smart substation. Reversely operating CPU operation results of two operation records about the relay protection device, in order to form corresponding disassembler codes. According to disassembler codes, calculating similarity of the CPU operation results of the two operation records about the relay protection device by a structured method. Judging whether the similarity is greater than a set threshold or not. If the similarity is greater than the set threshold, the CPU operation results of the two operation records about the relay protection device to be the same, otherwise, the CPU operation results of the two operation records about the relay protection device are judged to be different. The present invention avoids the misoperations of the relay protection device on operation.

Method of preventing misoperations about a relay protection device in a smart substation

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Xuchang, China

Junhong Qiu