Non-linear Load Harmonics And Research On Harmonic Suppression Technology

Due to the increasing development of power electronic technology and the growing use of non-linear loads, the problem of harmonic distortion becomes ever more and more important. Harmonics provoke voltage and current waveforms in the electrical distribution systems which are not sinusoidal. So the importance of harmonic analysis and suppress has been well recognized around the world.A general description of development of harmonic around the world is given in this thesis at first. It simply introduces the main mode of suppressing harmonic, the development of passive filter and active power filter, and the trends in APF. The basic concepts of electric harmonic as well as non-linear loads harmonic source production and influence are presented, and analyzed several non-linear loads harmonic source. Afterward mathematical model to the non-linear loads harmonic source is constructed, and drawn the conclusion by the mathematical formula. The simulation model of non-linear loads harmonic source power is giver in SIMULINK environment of MATLAB7.1 software. Simulation research proved the non-linear loads user influence the linear loads user.At the moment, in harmonic suppress aspect, it has had practical and mature passive filter technique, but it has many disadvantages. Therefore, these years much research turns to the active power filter for its prior function of compensating harmonics dynamically. This thesis put forward an improved harmonic detecting based on instantaneous reactive power theory considering that the power system is often under imbalance in our country, and this method only withdraws harmonic current but not withdraws fundamental negative...