Regenerative Inverter System for Railway with DC Line Voltage Simulator

직류가선전압 모의장치를 적용한 지하철용 회생인버터 시스템

In this paper, a unified regenerative inverter system for railway with DC line voltage simulator is proposed. In order to determine the operation characteristics of the regenerative inverter, the DC line voltage simulator is proposed. The DC line voltage simulator, which is based on the AC-DC PWM converter, varies the DC voltage according to the fluctuating voltage which is measured in the actual DC line. The suitable operating point of the regenerative inverter can be estimated from the simulation result. The regenerative inverter operates two modes. When the DC line voltage exceed the operating point, already set up, it works as regenerative inverter to return the excessive power of DC line to the grid. When the DC line voltage is under the operating point, it works as active power filter to compensate harmonic currents. In this paper, the control algorithm of the DC line voltage simulator and that of the regenerative inverter is proposed.