Research on adaptive protection based on integrated protection

Generally, the three-stage current protection and the instantaneous under voltage protection with current supervision are set to protect the low-voltage distribution system. The protection range of adaptive current instantaneous protection, irrelevant to the fault type of the power system, will be affected by the different operating mode of the system. When the parameters of power system satisfy certain relations, the minimum protection range will be less than 20% of the line length. The adaptive current instantaneous protection can not to be used in this case. This paper presents an approach to solve this problem by combining the adaptive current instantaneous protection with adaptive voltage instantaneous protection.