【摘要】 针对目前应用于直流配电网领域的DC/DC换流器造价高、控制复杂以及不具备直流短路故障穿越能力的缺点，为了实现不同电压等级直流分布式负荷有效接入直流配电网，提出了一种混合DC/DC换流器拓扑，采用电流源换流器(current source converter, CSC)连接直流电网，电压源换流器(voltage source converter, VSC)连接直流分布式负荷。提出的换流器拓扑具有结构简单、控制方式灵活以及具备直流短路故障穿越能力的优点。在分析换流器数学模型和运行约束条件的基础上，给出了换流器的参数设计方法，提出了一种CSC侧功率闭环控制，VSC侧交流电压幅值闭环控制的DC/DC换流器闭环控制策略。最后，在RTDS半实物仿真平台上搭建了1 MW/2 000 V/750 V混合DC/DC换流器试验模型，开展了额定运行工况、功率变化工况和直流短路工况试验。额定运行工况试验结果表明提出的拓扑可以实现1 MW额定功率的运行，功率变化工况试验结果表明提出的拓扑可以实现功率由1 MW到-1 MW的平滑反转，直流短路工况试验结果表明换流器能够平稳穿越直流短路故障。更多还原

【Abstract】 Aiming at the defects of DC/DC converter in the field of DC power distribution network, i.e. high cost, complicated control strategy and no DC short-circuit fault ride-through capability, a hybrid DC/DC converter topology is proposed herein for realizing the effective connection of DC distributed loads with different voltage levels to DC distribution network, for which current source converter(CSC) is used to connect to DC network and voltage source converter(VSC) is used to connect to DC distributed loads. The proposed converter topology has the merits of simple structure, flexible control mode and DC short-circuit fault ride-through capability. On the basis of analyzing the mathematical model and operation constraints of the converter, a parameter design method for the converter is given out, and then a closed loop control strategy of DC/DC converter with both the CSC side power closed loop control and the VSC side closed loop control of AC voltage amplitude is proposed as well. Finally, an experimental model of 1 MW/2000 V/750 V hybrid DC/DC converter is built up on a hardware-in-the-loop simulation platform for carrying out the experiments of the rated operation condition, power change condition and DC short circuit condition. The rated power experimental results verify that the proposed converter can realize 1 MW rated power transmission. The power change experimental results verify that the proposed converter can realize the transmitted power changing from 1 MW to-1 MW smoothly. The DC fault experimental results verify that the proposed converter can ride through the dc short fault steadily.更多还原