Reactive Power Optimization Dispatch Strategy in Distribution Network with Distributed Generators

In allusion to the current scenario on distribution networks containing distributed generation (DG), the coordinated dispatching of the compensating capacity of capacitors with reactive output of DG is not taken into account, a new optimisation and dispatching strategy of dynamic reactive power in distribution network with DG is researched in this study. This strategy takes into account the number of adjustment times for the capacitor banks. First, the Haar wavelet transform is used to segment and aggregate the payload power prediction curve of the distribution network. Second, the action sequence of the capacitor banks in the day is obtained. Finally, after the determination of the compensating capacity of capacitor banks, the day‐ahead scheduling of DG is drafted. A two‐objective optimisation function is made up of the voltage stability index of the weakest point of the system and the operation network loss. Then a dynamic reactive power optimisation scheduling model of the distribution network considering the voltage stability index is constructed. A modified particle swarm optimisation algorithm is used to analyse the simulation results in the modified IEEE 33‐bus distribution system. Compared with the present methods, the results show that the strategy can effectively improve the voltage stability of the distribution network in most of the day and limit the number of times of the capacitor banks to a given range in spite of the cost of slight increase of the network loss. Hence it is more practical to solve the problem of time–space coupling in dynamic reactive power optimisation.