The Algorithm Research Of Voltage/reactive Power Optimization For High-medium Voltage Distribution Networks

How to utilize and distribute reactive power resources rationally and scientifically, reduce and operating losses, improve power supply quality, is being paid more and more attention. Voltage/reactive power optimization in distribution network can solve the above-mentioned problems. Now, the researches of voltage/reactive power optimization in distribution network are local optimization. So that to the distribution network especially many voltage grade voltage, carrying on deep research about voltage/reactive power optimization problem in distribution network have many practical meanings.The focal point of the work of this paper is in the three following respects: First of all, forward/backward sweep method is improved on some aspects to calculate power flow of distribution network; Secondly, model and algorithm about voltage/reactive power optimization is proposed based on linear programming interior-point; Last, genetical algorithms is applied in distribution network voltage/reactive power optimization.Aiming for the disadvantages of the forward/backward sweep method in dealing with meshed distribution networks and PV nodes, an improved power flow algorithm based on the superposition principle for meshed distribution networks through revising power flow of the unlinked point continuously and correcting the reactive power of the PV nodes are proposed in this paper. Moreover, a bus-labeling method based on the adjacent nodes table is presented.Considering the characteristics of the high-medium voltage level distribution networks, the voltage/reactive power optimization (VRPO) is divided into two sub-problems: switching capacitors and adjusting tap ratios of transformers. The final result of the VRPO is gotten by alternatively solving the two sub-problems together. The algorithm is fastened by simplifying the constraints of node-voltages. Capacitor switching is formulated with the successive linear primal-dual interior-point programming algorithm which is improved in some aspects: transforming the model equivalently, solution the initial interior-point and integer problem etc. While taps adjusting is processed through the step-adjusting strategy to control the voltage and to reduce the tap-changing times.