Reactive Power Compensation Switching Methods

1.Delayed Switching Method, also known as "static" compensation. This switching method relies on the operation of dedicated contactors, which can suppress the inrush current of capacitors. The purpose of delayed switching is to prevent the contactors from operating too frequently, which could damage the capacitors. More importantly, it aims to avoid oscillations in the power supply system caused by continuous switching of capacitors, as this poses significant risks.

2.Instantaneous Switching Method, also known as "dynamic" compensation, essentially functions as a "fast follow-up system." The controller typically completes sampling and calculations within half to one cycle and issues control signals by the time the second cycle arrives. By using pulse signals to trigger thyristors, the switching of capacitor banks is completed in approximately 20–30 milliseconds for the entire process. This control method is something mechanical contactors cannot achieve. As a new generation of compensation devices, dynamic compensation has broad application prospects.

3.Hybrid Switching Method, which essentially combines "static" and "dynamic" compensation. In this approach, one part of the capacitor banks is switched using contactors, while another part uses power semiconductor devices. This method allows for complementary advantages to some extent, broadening the application scope compared to single switching methods and achieving better energy-saving effects. By selecting non-equal capacity capacitor banks for the compensation device, the compensation effect becomes more refined and ideal. Additionally, a phase-separated compensation method can be adopted to address losses caused by three-phase imbalances in the line.