Detection And Analysis Of Power System Harmonics Based On Instantaneous Reactive Power Theory

With the rapid development of modem industry and widespread application of power electronic devices,which leads to more and more serious pollution to power network for their non—linear feature and diversity.Harmonic pollution has a serious negative impact on the power quality and the normal operation of various electrical equipments.Real-time and accurate detection of harmonic quantity on power network is very necessary for preventing the harmonic harm and protecting safe operation of power network.This paper researches on harmonic current detection methods. The main contents are as follows:Firstly, this paper discusses some instantaneous reactive power theory of knowledge.Secondly, this paper researches on the harmonic current real-time detection based on instantaneous reactive power theory, the principle of method.This paper mainly researches on p-q harmonic current operation mode and ip-iq harmonic current operation mode based on instantaneous reactive power theory and analyzes the influence of the power grid voltage distortion and asymmetry on the test.Thirdly, this paper analyzes the influence of the low-pass filter types, order number, the choice of the cut-off frequency on the detection speed and precision.Fourthly, this paper builds the harmonic detection model by MATLAB simulation software and sets up the algorithm simulation model of p-q, ip-iq and dq0 harmonic current operation modes.The theory analysis and simulation operation shows that instantaneous reactive power theory of harmonic detection has the very good accuracy and real-time.