The Mechanical Characteristics Of Vacuum Circuit Breaker Switching Capacitor Bank Performance And Improvement

Vacuum breaker is widely applied in the reactive power compensation as the switch of shunt capacitor banks, which will cause reignition and over-voltage after the switching performance gets deteriorated.Firstly, the contributing factors leading to reignition and over-voltage are briefly discussed. Then, with the aid the systematic simplified model and circuit equation, the thesis analyzes in detail the types and range of over-voltage of the capacitor banks under different circuit and switching conditions. The damage and the expected control level are identified. By means of systematic analysis of the mechanism of reignition and over-voltage, the thesis points out that the improper mechanical characteristics of the vacuum breaker is the major factor leading to reignition and over-voltage, and further investigate deeply into the relationship among them ending with a comprehensive conclusion. Based on this, the thesis studys the control and improvement principle of the key mechanical characteristics of the vacuum breaker qualitatively and quantificationally, and attempts to develop a universal and maneuverable technical scheme. The aim is to reduce the reignition rate and over-voltage damage from the perspective of the mechanical characteristics of the vacuum breaker switching shunt capacitor banks.With the consideration that 10kV vacuum breaker is the most widely used in this field, the thesis takes the ZN28-10 vacuum breaker as a representative type and mainly analyzes the calculation and evaluation approach of this type on the respect of parameter. And at the end improvement measures has been proposed for the type with the capacity of 630A-20kA, and valuable results are obtained.