Method for optimizing protection action time of distribution line switch

The invention discloses a method for optimizing distribution line switch protection action time, which comprises the following steps of: 1, determining switch action time level difference on a distribution network line according to over-current protection action time of a transformer substation outlet circuit breaker, and sequencing switches in sequence according to a direction from a transformer substation to a load and a principle of first trunk line and then branch line; 2, constructing a distribution line switch protection action time optimization model according to the switch action time difference, the number of users between adjacent circuit breakers on the distribution network line and the length of the line between the adjacent circuit breakers by taking the minimum number of users influenced by power failure caused by a fault as a target; and 3, analyzing the established switch protection action time optimization model, converting the model into a linear model, and solving the linear model to obtain