Single Phase Automatic Powerfactor Corrector with Microcontroller Based Capacitor Bank Switching

This paper presents the simple design of an automatic power factor correction (APFC) system for single phase application. The design uses modified switching of the capacitor banks in order to correct the power factor of inductive loads. mechanical relays are easy to control and are more effective for high power application. The relay switching is controlled by an microcontroller programmed with modified switching technique. CT,PT and zero crossing detector are continuously monitoring the power factor of the load that connected and the microcontroller is programmed to keep the power factor of the load close to the reference value (0.9). To speed up the power factor correction process, capacitor value is calculated directly with reactive power calculation. A liquid crystal display is also provided for the visual information. The hardware prototype of the APFC design is also developed to validate its operation.