Voltage Amplitude Control of DC Power Regenerating Inverters with $\alpha$-Conduction Mode

$\alpha$도통모드에 의한 직류전력회생용 인버터 출력전압의 크기 제어

This paper deals with the voltage amplitude control in inverter systems which can regenerate the excessive DC power from DC bus line to AC supply in substations for traction systems. To maintain the magnitude of output fundamental voltage constant in spite of the variation of input DC voltage inverters are operated in symmetrical $\alpha$-conduction mode with the range of $120^{\circ}$<$\alpha$<$180^{\circ}$ To match the output voltage of the inverter systems with AC supply voltage harmonic reduction techniques are also investigated. Computer simulations are carried out to verify the validity of the proposed systems.