Method And Experiment Research On Extraction And Recovery Of Harmonic Energy In Distribution Network

With the development and expansion of electric power system, the nonlinear load in power system is gradually increasing, so is the harmonic pollution. Harmonic can not only shorten the life of electrical equipment, cause different kinds of fault, but also increase the network loss of power grid, reduce the power factor of power grid and efficiency of the production, transmission and utilization of electricity,then increasing the loss of electric power supply department. So studying the harmonic power loss, harmonic suppression and the method for extraction and recovery of harmonic electric energy has important significance on electric system. This paper aimed at the problem that the distribution network harmonic caused energy loss while conventional methods caused waste of energy and then put forward the methods of harmonic energy extraction from the low impedance path. This paper analyzed the calculation method of harmonic loss, and on this basis put forward the method of harmonic energy extraction and constructed the structure of the system, and then this paper analyzed and designed the low impedance path together with the harmonic energy extraction coil. Finally, library tests were conducted according the methods. The main researches are as follows:â‘ This paper analyzed the harmonic loss in the distribution network, then deduced the calculation formula of harmonic loss considering the skin effect, proximity effect and eddy effect. Through the analysis and calculation, the relationship between harmonic loss rate and harmonic distortion rate together with the scale of harmonic loss in the total loss are confirmed.â‘¡Aim at the problem that the conventional method may cause waste of energy, this paper put forward the harmonic energy extraction method and constructed the system. And then designed the single harmonic tuning circuit for a particular harmonic load, proposed an improved method and realized the propose of improving power quality and reducing harmonic loss.â‘¢On the basis of single-tuned filter circuit, this paper put forward the scheme for extraction of harmonic energy, extracted energy through the primary coil of mutual inductance coil and output, and finally achieved the extraction and recovery of harmonic energy. The paper analyzed the operating characteristics, the influence of core material, turns and other parameters and determined the parameters. The paper got the characteristics closer to the actual results through Saber simulation software and verified that the harmonic energy extraction coil can output power when in the primary coil reach certain current.â‘£The paper conducted the experiments of low impedance path and harmonic energy extraction. The results prove that the single-tuned filter circuit can effectively reduce the harmonic current flowing into the grid and enhance the power quality, especially when the reactor is connected in series to the line. And the experiments of mutual inductance coil working with load or not verified that the mutual coil is capable of transmitting energy and that inducting harmonic wave current in the primary side of mutual inductance coil can achieve extraction of harmonic energy.