Study Of A Three-Phase Current Source Converter For Active Superconducting DC Fault Current Limiter

Active Superconducting DC Fault Current Limiter(DC-SFCL)makes use of power electronics technology and superconductive technology. It has been widely applied in DC power system, and it can be used to improve the security and stability of DC power system. Power electronics converter or so called power conditioning system(PCS)is the bridge between the superconducting transformer and the AC power network, it is a key parts of the active DC-SFCL. Comparing with the voltage source converter, current source converter has advantages on technology and economy.Excellent CSC is important for active DC-SFCL to play satisfactory limiting performance, agility and reliability. This thesis is devoted to a development of Current Source Converter(CSC)for the active DC-SFCL. The content of the thesis follows:The thesis introduces the basic theory of the active DC-SFCL and the structure of CSC, a method of Sinusoid Pulse Width Modulation for CSC and Space Vector Pulse Width Modulation are given in the thesis.At three phase stationary frame based model, a two phase stationary frame based model and a synchronously rotated frame based model for CSC are established at first. The switch function models based on three reference frame for CSC are given in the theses.A power control scheme is proposed in the thesis. The thesis contains the detecting of instantaneous power, the relation of between M,αand power, and the design of PI adjustor.The design and the implementation of the CSC experimental setup are presented in details. The selection of switch transistor, the design of inductance and capacitance and the design of driving circuit are discussed in the thesis. The control card and programme design are introduced in the thesis.