Power grid purifier

A power capacitor is widely used for reactive power compensation because of simplicity and low reactive power loss, and has the defects of discontinuity of compensation capacity, poor dynamic characteristics and easy generation of resonance. At present, the most representative static var generator SVG injects reactive compensation current into a power grid through the output voltage of an inverter, and the cost is too high. According to the power grid purifier disclosed in the invention, the defects of the above two reactive power compensation methods are overcome, an electronic switch circuitis used, a power grid live wire is connected with a power capacitor, and the current of the power capacitor is controlled in real time by changing the pulse width duty ratio, and a phase angle of thecurrent is also controlled. Due to the fact that only connection is adopted, a low-voltage large-current MOS tube can be adopted, the MOS tubes can be directly connected in parallel for capacity expansion, and the performance