电力系统容性无功及补偿

Capacitive Reactive Power and Compensation in Power System

电力系统供电网络中的输电线路及电缆,在运行中要产生容性无功。由于城网改造配电网络主要由高压电缆组成,高压电缆产生的容性无功严重影响配网的安全经济运行。为解决电力系统容性无功过补问题,我们从电力系统容性无功的产生机理进行分析,找出电力系统容性无功产生的特点及解决办法。结果表明电力系统容性无功功率取决于电网中输电线路及电缆的结构及长度,电网结构确定以后,它的容量相对固定,变化不大。因此对电力系统容性无功的补偿应相对固定并采用分散补偿和集中补偿相结合的原则进行配置。同时针对1 0 kV及35 kV小电流接地系统因接地电容电流增大引起的消弧线圈容量增大,运行可靠性降低问题,研制出了既有感性补偿又能减少接地电容电流的装置Y接电抗器灭弧装置,对它的原理构造,性能进行了介绍。

Capacitive reactive power is generated in the transmission line and cable in power supply network during operation. Since the distribution network of urban network modification is mainly composed of high voltage cables, in which the capacitive reactive power generated has a serious impact on the safe and economic operation of distribution network. For solving the over compensation issue of capacitive reactive power of power system, the analysis is made from the generation mechanism of the capacitive reactive power in the power system, the features of such reactive power of power sys- tem and solution are found. It is shown by the result that the capacitive reactive power in the power system is determined by the structure and length of transmission line and cable of the power network. Once the network structure is determined, its capacity is relatively fixed with less variation. There- fore, the compensation to capacitive reactive power of power system shall be relatively fixed and such principle as spread and concentrated compensation is adopted for disposition. As for reduction of op- eration reliability due to capacity increase of arc supersession coil because of the increase of earthed capacitive current in the small current earthing system at 10 kV and 35 kV, the extinction device named Y connection with both functions of inductive compensation and reduction of earthed capaci-tive current is developed its principle and performance are introduced.