DEVICE FOR ELIMINATING VOLTAGE HARMONICS IN POWER SYSTEM

摘要

A device for eliminating voltage harmonics in a power system, comprising a harmonic voltage source detection device (1, 2), a fundamental wave filter comprising of a first reactor (3), a second reactor (4) and a capacitor (5) in series, a high-frequency transformer (6), an alternating current power supply (7), a power unit (8), a rectifier unit (9), a filter unit and a controller (10). The harmonic voltage source detection device (1, 2) collects and obtains the real-time harmonic voltage of the system, and inputs a harmonic voltage signal into the controller (10); the controller (10) calculates and obtains a voltage with equal magnitude but opposite direction as the harmonic voltage, the voltage is outputted by the power unit (8) and inputted via the high-frequency transformer (6) into an LC branch comprising the second reactor (4) and the capacitor (5) in series; the voltage overlays the harmonic voltage so that the harmonic output voltage is zero, thereby achieving the function of filtering the harmonic voltage in a power grid; the controller (10) is connected to the alternating current power supply (7), the rectifier unit (9) and the power unit (8) respectively. Based on the superposition principle, the device can eliminate the impact of the higher order harmonic voltage source on the power supply side to the load through the serial harmonic voltage source and with fast response.