Studies Of The Multi-Function Balance Transformer's Filtering

Because of the fluctuating characteristic of the load in electrification railway and rectifying equipments, lots of high harmonic waves are produced and fed back to the power system. This phenomenon can affect electricity quality. The Ministry of Railway and the Ministry of Power attach importance to the problem for a long time and harmonic waves is an important scientific research task in the development of the electrification railroad. At present, several ways can depress the harmonic waves . Firstly, we can fix some filtering equipments in engines, which can filtrate harmonic waves in the course of run. Secondly, at the 27.5kV side of the draught transformer substation, we can fix parallel connection filtering equipments about LC to compensate the reactive power, but the collocate in parameter of capacitance and reactance must avoid magnifying the harmonic waves. Thirdly, the recent electric power filters which are studying don't satisfy engineering's need because of the poor technique. The two former are the passive filter mode, while the latter is the active filter mode.Combined with the scientific research task "the effect of the Multi-Function Balancing Transformer to reducing harmonics' disturbance" which I have participated in, the paper discusses the method that by the means of impedance matching tapping a 10.5W wire from the Multi-Function Balancing Transformer's secondary and connecting it with a three-phase symmetry filtering equipment, then bring forward the project about filter configuration and test it in the field engineering. At last by means of theoretic analysis and analyzing the testing data, it indicates that this filtering have the better effect in harmonic wave depression. Meanwhile, because of the voltage which the compensation equipment must endure reduces much, the amount of investment will cut down deeply.