Research On The Control Of The Overall Harmonic Attenuation In Radial Distribution Network Based On The Location Of DFAGTAF

With the development of national economy,electric energy plays an increasingly important role in the whole society. High quality electric energy is able to not only accelerate the development of economy,but also affect people’s living level.The power factor correction capacitances in radial distribution network and the inductances of system occur serious resonance phenomenon,and the harmonic will be grossly enlarged by resonance in the distribution network system, which lead to low quality of electric energy,thus speeding up the aging of lines and the lifetime of the electric equipments.Firstly,based on the transmission line theory,this paper establishes the 9km ray type of uniform transmission line and the parameter changing transmission line.Given that the formula of the fifth harmonic and the seventh harmonic resonance mechanism are derived.And as well the resonance peak points of the 5 harmonic and the 7 harmonic are obtained.Secondly,by installating Discrete Frequency Automatic Gain Tuning Active Filter in the terminal of the ray type distribution network, it is concluded that the active filter can only suppress the harmonic amplification phenomenon at the end of the line,however,while it cannot achieve the harmonic attenuation for the whole line,which is caused by the conclusion of the resonant voltage.Therefore, this paper puts forward the harmonic decay program of the discrete frequency automatic gain tuning active filter(Discrete Frequency Automatic Gain Tuning Active Filter, DFAGTAF) optimal installation positions, drawing the conclusion that the harmonic source peak which close to the harmonic source is optimal installation position of DFAGTAF.The program can not only achieve harmonic attenuation effectively but also can achieve good harmonic attenuation effect on the other line buses. Meanwhile,the program has strong robustness when the distribution line parameters change and nonlinear loads switch. Subsequently, the APF’s standardization is carried out, which lead to the conclusion thar when the APF is in the optimal installation position, the APF’s per unit value is the smallest.In the process of the experiment,the simulation 9km ray type of transmission line andsingle phase APF experimental platform are built to control the chip of TMS320F2812 in the single-phase APF. The experimental waveforms are obtained at the situation that the APF was respectively arranged in the transmission line of each buses.Based on that,the author carries on the contrast analysis respectively.Simulation analysis and experimental results verify the correctness and effectiveness of the program.