Difference Between Reactor And Capacitor

Difference Between Reactor and Capacitor

1. Different structures

The reactor is the inductor, the structure of the inductor is similar to that of the transformer, but there is only one excitation coil;

A capacitor is two conductors that are close to each other, with a layer of non-conductive insulating medium in between.

2. Different effects

The series reactor is mainly used to limit the short-circuit current and maintain the bus voltage;

The shunt reactor is used to compensate the capacitive current of the ultra-high voltage long-distance transmission line, prevent the voltage rise of the light load line terminal, maintain the voltage stability of the transmission system; improve the voltage distribution along the line and the reactive power distribution in the light load line, reduce the line loss, and reduce the potential Supply current, accelerate the extinguishment of the submerged arc, and improve the success rate of automatic reclosing of the line;

Appropriately matching the reactor with the frequency converter can effectively prevent the impact of the overvoltage and surge current caused by the operation of the incoming line switch on it, and can also reduce the pollution of the harmonics generated by the frequency converter to the power grid. It can improve the power factor of the inverter.

Capacitors are capacitive loads and are mainly used for reactive power compensation and energy storage.

3. Different characteristics

Inductance has the function of "blocking AC and passing DC", that is, using the characteristics of inductive reactance in AC circuits to "pass low-frequency DC and block high-frequency AC". Capacitors have the function of "communicating and blocking DC", that is, in AC circuits, the frequency characteristics of capacitive reactance are used to "pass high-frequency AC and block low-frequency DC".

 The origin of reactors and capacitors：

Because reactance includes inductive reactance and capacitive reactance, a more scientific classification should be that reactors include inductors (inductors) and capacitive reactances (capacitors). But since there were inductors first in the past, and they were called reactors, what people call capacitors is capacitive reactors, and reactors refer to inductors. Whether it is accurate or not, it has become a habit, a bit preconceived.