REDUCTION SYSTEM FOR DC SIDE HARMONIC DISTURBED CURRENT AT SINGLE-PHASE INVERTER

摘要

PURPOSE:To eliminate the disturbance to a signal frequency by generating equally divided pulses higher than two pulses at every positive and negative half cycle of outputs in an inverter for a railway train, thereby enhancing the frequency of the ripple current contained in an input current. CONSTITUTION:A single-phase inverter carried on a railway train is formed by connecting in bridge four switching valves S1-S4, the input terminals are connected through a filter of a reactor L and a condenser C between a pantograph P and rails R, and a load RL such as room heating heater or the like is connected to the output terminal. The valves S1-S4 are controlled to generate equally divided pulses more than two pulses in the respective positive and negative half cycle of output current wavefosms. Accordingly, the fundamental wave frequency of the ripple current contained in the input current of the inverter can be enhanced, thereby eliminating the disturbance to the frequency of other current flowing through the rails R.