The Best Optimization Design Of Injection-type Hybrid Active Power Filter

With rapid progress has been got in economic construction, there is more and more demand for energy supply. VAR and harmonic became serious pollution in electric power system. It results in abnormal working of various equipments in electric system. Then arouse the waste of energy sources, and there are many hidden trouble in electric power net and user. So how to improve the power quality is the one of the most pressing problem in power system. Faced to the weak structure and technology of power grid which in the low level of automation now. So to research new technology and equipment of AVR and harmonic has a very important theoretical and practical significance. At present, in our country we usually use passive filters to control power quality, and there was a small number SVC which has been invested in the power grid. But the above methods have some defects, such as low technology,not real-time compensation. So, they must be gradually replaced in the future.At first the paper introduced the background and control technology of harmonic. In this paper it choice the Three-Passive filter with less power loss which it can get rid of three characteristics of harmonic and compensation a large number reactive power. The capacitor and reactor constitutes a fundamental resonant circuit in the inject slip, As far as possible, the active filter output current is injected into the power grid in order to control harmonic. Active power filter use PWM inverter voltage to adjust the amplitude and phase of the output in real time, so the value of the harmonic and the stack offset system harmonics. The use of isolation transformers is to electrically isolate the passive filter and active filter. On other hand it can make active power filter and power grids to meet the voltage to match. In this device the detection system based on detection for reactive and harmonics currents of unbalanced three-phase systems based on synchronous reference frame transformation, and it take note of the dead-time compensation when the active filter produced the PWM pulse by the control of IGBT switches. At last the simulation in this paper is based on the MATLAB/Simulink software platform, and the 10Kv bus wire harmonic filter and reactive power compensation of a smelter simulated by this software to verify the feasibility of the operation of filter device. By analyzing the simulation results analysis, to determine the type of filter a good filter performance and function of reactive power compensation.