Research And Design Of Intelligent Capacitor In Low Voltage Reactive Power Compensation System

Reactive power is an indispensable part of the power grid. However, with the increasing of the power load, especially the use of high power inductive load, resulting in that the reactive power shortage becomes more and more obvious, so we need to compensate reactive power for the power grid. In the low voltage reactive power compensation system of our country, often exists the reactive power compensation technology is backward, the compensation precision is low, the response speed is slow and so on, which directly lead to the big loss of power supply system, the poor economic performance. Therefore, the development of intelligent, high stability and reliability of the reactive power compensation devices, plays an important part to the low-voltage distribution network.We introduce the significance of reactive power and reactive power compensation in detail firstly, and combine the research situation and development trend of reactive power compensation device at home and abroa, then analyze the function and technical index of the device which is suitable for low voltage reactive power compensation. Aiming at the impact current of capacitor in the switching process, as well as the "switching oscillation" problem in the control process, we design an intelligent capacitor which uses the composite switch to cut or input and adopts the integrated control strategy.In the specific implementation process of intelligent capacitor, in accordance with the idea of modular design, we analyze and design the concrete characteristics of each function module. The design of hardware circuit mainly includes that:signal acquisition and processing circuit, composite switch circuit, composite switch driving circuit and so on; the software design mainly includes thatrMain program design, capacitor switching control program, communication subroutine, etc.Finally, we test and analyze of the whole function of intelligent capacitor. A large number of experimental data show that this intelligent capacitor can accurately compensate reactive power in the system, with high compensation accuracy, stable and reliable operation and so on.