Research Of Distribution Network Voltage Stability Control Scheme

With lots of power electronic devices put into use in the grid, a great number of harmonic will emerge in the grid. This will result in a big impact for the voltage quality in the grid. In order to improve the stability of power grid, lots of measures are adopted, such as adding various compensation devices and the load regulating transformer, and so on. However, there are also some hidden troubles in the system stability because of incorrect use these measures.This paper analyze the voltage quality in the grid in theory and some simulation study, and based on this, the factors that give rise to the instability of power grid voltage are found out. A variety of voltage quality control methods are put forward aim at existent problem in the present distribution network voltage quality, and the regulating effect are compared for the the different compensation measures.This paper firstly analyzes several important reasons that lead to voltage instability and the principle of the reasons on the voltage instability. And then these reasons are classified and compared. Based on the study of our country present stage electricity characteristics and the trend of the development of the electric power, some solutions to these problems and its theoretical basis are analyzed. At the same time, the measures taken in the foreign are introduced. In the MATLAB/SIMULINK environment, the voltage stability for power distribution network is simulationed and studied. The system voltage variation for using shunt capacitor, static var compensator (SVC) and some other measures are separately carried on the simulation. According to the characteristic of the distribution network, the effective methods are proposed to solve the distribution network voltage quality problem, such as, employing the reactive power compensation technology, changing tapping point of the transformer, and according to the frequency or voltage to cut load technology. The dispersion compensation technology along the route and series voltage compensation technology are analyzed extraordinarily. Based on the analysis of the trend of dispersion compensation and load flow calculation, the different reactive power compensation point has different influence on power loss and voltage distribution.