Research Of Distributed Voltage And Reactive-power Control System Based On Global Optimization

Distribution network is an important part of power system directly facing consumers. Reactive power optimizing problem takes a super important role in protecting the secure operation of network and power supply. The electric quality is mainly reflected by the voltage; the power loss is technical and economic index of electric utility. Some research work of voltage reactive power optimization control of region network has been done in order to improve the voltage quality and decrease the power loss. Model and rule of reactive power optimization control of substations are analyzed based on the domestic and abroad status. The article proposes the idea to realize voltage and reactive power optimization control distributed. At the same time, presents voltage reactive power control based on distribution control. The research includes following contents:1. A novel concept named reactive power optimization and control method based on the controlling of voltage and reactive power to all rated buses of substation is present in this paper. Based on this concept, the host station can get the information of load and states of switches through communicating with subsystem. We can optimize the reactive power in all power networks utilizing the model of dispersed reactive power optimization and expanded interior algorithm; besides, this paper gives the computational method of the control tension of voltages and reactive power in power station .At the same time, the distributed and parallel reactive power optimization algorithm based on sub-area division of the power systems is firstly combined with the multi-agent technology according to its characteristics .A novel voltage and reactive power optimal control system based on the multi-agent technique is proposed after the control sub-area division problem are solved. The distributed and parallel reactive power optimization algorithm based on sub-area division of the power systems is firstly combined with the multi-agent technology according to its characteristics.2. EW Equivalent reactive power optimization algorithm based on sub-area division of the power systems . The merits and shortcoming of the existing optimization algorithms are summarized .According to these summarizations , optimization algorithm is required to be adaptive to the distributed and decentralized characteristics of power systems , thus leads to a fast convergence property, minimum data transfer and easy application .So the article proposes the idea to realize voltage and reactive power optimization control distributed. Then partition equivalent model is built, which can split the big power system into several subsystems, so the problem can be solved parallel, and the global optimization can be obtained through the linking nodes communication.3. This paper takes the direct nonlinear primal-dual interior point arithmetic to resolve the voltage and reactive optimization problem. The arithmetic starts at an interior point, gets the next interior point in the descending direction of object value, then from this point, gets another interior point in the descending direction of object value. A series of interior points are gotten by repeating the above steps. When the ending rule is satisfied, the optimized object value is gotten. This paper also discusses several problems in its solution, such as the choice of corrector steps and decision of obstacle gene. It also introduces the principle of advanced predictor-corrector primal-dual interior point arithmetic, that is by introducing predictor and corrector to correspond the optimization and feasibility, the convergence ability is improved.4. This paper empolders the system of voltage and reactive power controlling and optimization based on distribution control .The system has been used at Zaozhuang Power Supply Company , and abtained lots of social and economic benefit , such as dynamic reactive compensation reducing net loss; improving the quality of electric energy ; automatic and load-ratio adjust voltage transformer; advancing the passing percent of voltage.