Research on a non-impact transient reactive power compensation device based on anti-parallel IGCT valve group and passive device combination

Dynamic reactive power support is needed during system voltage sag or sag to increase the amplitude of residual voltage, speed up the recovery of system voltage and reduce the risk of voltage collapse. In this paper, a non-impact transient reactive power compensation device based on the combination of anti-parallel IGCT valve group and passive devices is proposed, which has the functions of reactive power compensation and harmonic absorption during the normal operation of the power grid, provides dynamic reactive power support quickly during the voltage sag or sag of the system, improves the amplitude of residual voltage and accelerates the recovery speed of the system voltage. The device adopts non-impact switching logic, and the dynamic reactive power compensation function is put into operation when the peak current of the main capacitor and the corresponding voltage are zero, so as to ensure that there is no impact inrush when the reactive power compensation device is put into operation and avoid the secondary impact on the power grid when the device is put into operation; When the current of the main capacitor is at the peak and the corresponding voltage is zero, the dynamic reactive power compensation function is exited, which ensures that the capacitor has no residual voltage and DC component, and reduces the voltage stress requirements of the auxiliary capacitor and IGCT valve group. This device has a broad application prospect in the field of high voltage dynamic/transient reactive power compensation, and it will play an important role in improving the transient stability of the system, increasing the dynamic reactive power reserve and ensuring the safe and stable operation of the power grid and high-speed rail locomotives.