Non-Integral AC Capacitor Voltage Calculation Method for Shunt Hybrid Active Power Filter

Abstract

This paper introduces a novel non-integral method for calculating AC capacitor voltage in shunt hybrid active power filters (SHAPFs). These filters commonly use passive power filters (PPFs) that can introduce voltage containing harmonics into the AC capacitor, leading to overvoltage situations that can be dangerous. To avoid accidents due to overvoltage, it is necessary to monitor the AC capacitor voltage continuously. The proposed method enables the calculation of the voltage across the AC capacitor, using only the sensor available in the SHAPF, without requiring additional sensors. By avoiding the use of integration to calculate the voltage, the method effectively mitigates errors due to DC offset inflows. The effectiveness of the proposed method was verified through simulations and actual experiments. Results demonstrate that the proposed voltage calculation method improves the voltage calculation accuracy by approximately 1.93[%] when compared to the general voltage calculation method. The proposed non-integral AC capacitor voltage calculation method represents a significant advancement for SHAPFs, providing an effective means for reducing overvoltage risks, without requiring additional sensors or costly equipment.