Consideration on self-commutated converter characteristics for DC power supply

A new DC power supply system is proposed based on the advanced current source type self-commutated convertor (ACSC). The ACSC is a network-friendly convertor and expected to achieve the high accuracy of 10^-5 to 10^-6 range of the DC current and required in the accelerator electromagnet application. The ACSC system performance is studied through digital simulation with the EMTDC (Electro Magnetic Transients program for Direct Currents transmission) and two control methods are discussed. A system consisting of the voltage source self-commutated convertor (VSC) and the choppers is also evaluated. Furthermore, characteristics of power conversion systems are discussed especially on the coordination between the convertor and the AC network. It is indicated that the convertor selection needs careful consideration on both the DC power quality requirements and the AC network conditions