Harmonic current detection based on general theory
of instantaneous reactive power
YANG Huairen, CHEN Longdao, LAI Xiaohan
(College of Electrical Engineering, Zhejiang University, Hangzhou 310027, China)
Abstract: Aiming at the limit of traditional harmonic detection only detecting total quantity of harmonic currents in power system, a new algorithm based on general theory of instantaneous reactive power was investigated. By the ipiq generalized coordinate transform, the detected harmonic current becomes a DC component and can be filtered by a low pass filter. Then the specific harmonic current can be obtained by inverse coordinate transform. At last, it is proved the detection result is not influenced by phase deviation under asymmetrical threephase voltages. The experimental results indicate that this method is highly flexible as positive and negative sequence component of random harmonic current can be detected respectively by only modifying the switch matrix. Simulation result shows this method is available.
Key words: threephase asymmetrical system; random harmonic current; instantaneous reactive power; Matlab