电力系统的无功功率和电压调整（Reactive power and voltage regulation of power system）.doc

电力系统的无功功率和电压调整（Reactive power and voltage regulation of power system） Reactive power and voltage regulation of power system First, reactive power load and reactive power loss Reactive power load: most of them are asynchronous motors Reactive power loss: 1. transformer; 2. transmission line. Reactive power loss in transformer is divided into two parts, that is excitation branch loss and winding leakage resistance loss. Among them, the 100 percent value of the excitation branch loss is basically equal to the hundred percent of the no-load current. The loss of the winding reactance is about 100 percent of the short-circuit voltage when the transformer is loaded. Therefore, for a transformer or a transformer network, the reactive power loss in the transformer is not large, when the load is about 10 percent of its rated capacity. But for multilevel voltage networks, reactive power losses in transformers are considerable. Reactive power loss in power line is also divided into two parts, that is, reactive power loss in shunt admittance and series reactance. In parallel, this loss is called charging power, which is proportional to the square of the line voltage and capacitive. The loss in series reactance is proportional to the square of the load current and is sensible. Therefore, the line as a component of the power system, the consumption of capacitive or inductive reactive power can not be sure. However, it can be roughly estimated that when the active power delivered through the line is greater than the natural power (the so-called natural power is the power consumed by the load when the impedance is the impedance of the wave) When the active power delivered by the line is less than the natural power, the line will consume capacitive reactive power. Two 、 reactive power supply in power grid 1. generator Synchronous generator is not only the active power supply, but also the basic reactive power supply. 2. capacitors and tuning cameras Shunt capacitors can only supply i