Study and early warning of comprehensive distribution box state based on maximum likelihood parameter estimation of Weibull distribution

With the expansion of the power grid scale and the improvement of distribution box automation, the structure of the distribution network has become more complex, and the maintenance task is heavy. The traditional post-maintenance and regular maintenance modes could not satisfy the requirements of distribution network equipment operation reliability. Firstly, according to the maintenance mode, the failure rate curve is proposed based on Weibull distribution. The service age reduction factor and the current failure rate of the equipment are mapped in this paper to the failure rate curve based on Weibull distribution. Secondarily, they are used to calculate the actual service age of equipment. The annual failure rate of equipment is used to count and determine the failure rate increment factor. Thirdly, the ant colony algorithm is applied to Weibull distribution maximum likelihood parameter estimation. Finally, an example analysis verified that the parameter accuracy of ant colony algorithm estimation is higher. Thus, the correctness of the state-based equipment failure rate estimation method is verified, which lays a foundation for the formulation of a maintenance plan.