级联H桥分布式潮流控制器的电压、阻抗和功率等值建模

Equivalence analysis of voltage,impedance and power relationships of distributed power flow controller based on cascaded H-bridge converter

级联H桥分布式潮流控制器(Distributed Power Flow Controller,DPFC)无需使用升压变压器,可以直接串联进高压交流输电线路对线路有功功率进行控制。本文深入分析了分布式潮流控制器的电压和电流相量关系,建立了感性工况和容性工况通用的级联H桥分布式潮流控制器稳态数学模型,提出了分布式潮流控制器的电压、阻抗和功率的等值变换模型,其中阻抗等值模型可以将分布式潮流控制器输出电压与其等值电抗进行等值变换,功率等值模型可以将分布式潮流控制器输出电压与其串联线路首端或末端输送功率进行等值变换,用于对分布式潮流控制器的运行潮流、参数选型等进行计算分析。电磁暂态仿真结果验证了分布式潮流控制器等值模型的准确性,当分布式潮流控制器输出电压增大时,其等值电抗也将增大,线路输送有功功率将减小。

Distributed power flow controller(DPFC)based on cascaded H-bridge converter is connected in series with the high-voltage transmission lines to control the delivered active power without using step-up transformer.The voltage and current phasors in DPFC system are analyzed in depth,and a steady-state DPFC model for both induc-tive and capacitive operation conditions is established.The impedance and power equivalent models of the DPFC system are proposed.The relationship between the DPFC voltage and its equivalent reactance is described by the impedance equivalent model,while the relationship between the DPFC voltage and the transmission line power is given by the power equivalent model.The simulation studies are performed on the detailed electromagnetic transient simulation model of the DPFC system,by which the equivalent models are validated.With the increase in the DPFC output voltage,the equivalent reactance is increased and the transmission line power is decreased according-ly.