STRUCTURE OF HYBRID POWER FILTER FOR REACTIVE POWER AND HARMONIC CURRENTS IN TRACTION SUBSTATION

To compensate the harmonic current and reactive power of the traction substations, according to the specific property of traction supply system a novel structure of hybrid power filter is proposed. The hybrid power filter is composed of passive power filter, active power filter and switchable reactive power compensation device. The hybrid power filter has two features, it is a stationary harmonic filtering channel and has less initial investment. The working principle of the switchable reactive power compensation device is analyzed, the detecting method for harmonic current and reactive current is proposed and the control strategy of the hybrid power filter is given. A simulation model for a certain traction substation is established on the Simulink flat in MATLAB. The simulation results show that the performance in the compensation of harmonic current and reactive power of the proposed hybrid power filter is satisfactory.