提出了一种具有特殊接线方案的改进型感应滤波高压直流输电系统,其2个换流变压器的公共绕组并联后接1套全调谐感应滤波器组,且滤波器组中不含有5、7次滤波器,仅为11、13次双调谐滤波器,大幅减少了滤波器和开关等设备的投入。分析了改进型感应滤波高压直流输电系统的谐波传递特性,分析结果表明此系统同样能够有效地将谐波电流屏蔽于换流变压器的阀侧绕组,减小网侧绕组的谐波电流。最后对一背靠背的12脉波改进型感应滤波直流输电系统试验平台进行试验测试,测试结果验证了理论分析的正确性,说明了改进型感应滤波直流输电系统的可行性。
An IHVDC-IF(Improved High Voltage Direct Current transmission system based on Inductive Filtering) with special wiring pattern is presented,which connects a set of fully-tuned inductive filters,containing only the 11 / 13 double-tuned filter and without the 5 / 7 double-tuned filter,to the common winding of two parallel converter transformers to greatly reduce the investment of equipments,such as filter,switchgear,etc. The harmonic transfer characteristics of IHVDC-IF are analyzed and the analytic results show that,the presented IHVDC-IF is also able to effectively shield the harmonic currents in the valve-side windings of converter transformer and reduce the harmonic currents of grid-side windings. A test platform of back-to-back 12-pluse IHVDC-IF is used to verify the correctness of theoretical analysis and the test results illustrate its feasibility.