Reactive Power optimization of Distribution Network with Large-scale Underground Cables Considering Power Factor Constraints

At present, capacitive reactive power surplus is becoming increasingly prominent at light load operation in large urban power grid, which hazards the safety and stability of grid. Based on this background, the reactive power optimization method of distribution network with large-scale underground cables is studied. Firstly, an integrated reactive power optimization model with reactor and capacitor is established, taken into consideration power factor constraints. The objective function of the model is to minimize the real power loss. The new constraints include power factor constraints of buses and size constraints of reactors. Then, an improved genetic algorithm is proposed to solve the model. The real power loss sensitivity with respect to reactive power compensation is applied to improve the mutation process. By coordinating the operating and values of capacitors and reactors, the optimized scheme can avoid reactive power reversal and power factor exceeding the limit in the distribution network with large-scale cables access. Finally, a typical high voltage distribution network is used as an example to verify the effectiveness of the model and algorithm.