Abstract:

Aiming at the problem that the non-convexity introduced by the step voltage regulator model causes the distributed algorithm to fail to converge, a distributed voltage control strategy for photovoltaic high-penetration distribution network combining alternating direction multiplier method and branch and bound algorithm is proposed. Firstly, the distribution network is divided into multiple clusters according to the position of the step voltage regulators. Each cluster aims to optimize the economy to eliminate the internal voltage violation and obtain a local optimal scheduling scheme. Secondly, adjacent clusters exchange boundary information, the alternating direction multiplier method is used to coordinate and optimize the clusters, and the scheduling scheme that meets the global constraints is obtained through continuous iterations. Thirdly, the nonlinear integer equality constraints introduced by the step voltage regulators is slack to linear inequality constraints based on the branch and bound method to obtain the optimal gear of the step voltage regulators. Finally, the improved IEEE 33 node distribution network is used to verify that the proposed voltage control strategy can give full play to the advantages of step voltage regulator, effectively solve the problem of distribution network voltage over-limit and promote distributed photovoltaic consumption.

Key words: Distribution network, step voltage regulator, distributed voltage control, alternating direction multiplier method, branch and bound method