This paper focuses on a shunt active filter based on the detection of harmonic voltages at the point of installation. The objective of the active filter is to attenuate harmonic propagation resulting from series/parallel resonance between capacitors for power factor correction and line inductors in a power distribution line. The active filter acts as a low resistor to the external circuit for harmonic frequencies, and it is installed on the end bus of the power distribution line, just like a 50 O terminator installed on the end terminal of a signal transmission line. Therefore, the function of the active filter is referred to as harmonic termination in this paper. Experimental results obtained from a laboratory system rated at 200 V and 20 kW verify that the active filter for the purpose of harmonic termination has the capability of harmonic damping throughout the power distribution line
NONLINEAR loads such as high-power diode/thyristor rectifiers, cycloconverters, and arc furnaces draw nonsinusoidal currents from utility grids. A single low-power diode rectifier used as a utility interface in an electric appliance produces a negligible amount of harmonic current. However, multiple low-power diode rectifiers can inject a large amount of current harmonics into power distribution systems. These harmonic-producing loads contribute to the degradation of power quality in transmission/distribution systems.
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