电网换相换流器整体化电磁暂态仿真模型及算法

Integrated Electromagnetic Transient Simulation Model and Algorithm of Line Commutated Converter

现有的电磁暂态仿真算法能够准确刻画基于电网换相换流器的高压直流(LCC-HVDC)输电系统的运行特性,但计算量较大。为了提高LCC-HVDC输电系统的仿真效率,对现有常用的电网换相换流器电磁暂态仿真模型进行了简化,提出电网换相换流器整体化电磁暂态仿真模型与求解算法。整体化模型包含换流变压器与换流阀,换流变压器采用简化模型,换流阀采用理想开关模型,能够对换流器的电气网络结构进行简化。该算法将换流器电气网络拓扑结构分割为主网络与副网络,首先对主网络求解,然后根据得到的结果对副网络求解,最后更新当前仿真步长各换流阀的电流和电压。在PSModel仿真软件中对整体化电磁暂态仿真模型及算法进行了编程实现,并与PSCAD/EMTDC仿真结果进行对比,验证了其高效性与准确性。

The existing electromagnetic transient simulation algorithm can accurately reflect the operation characteristics of line commutated converter based high voltage direct current(LCC-HVDC)transmission systems,but the amount of computation is large.In order to improve the simulation efficiency of LCC-HVDC transmission systems,the existing electromagnetic transient simulation model of LCC-HVDC transmission systems is simplified,and the integrated electromagnetic transient simulation model and solution algorithm of LCC-HVDC transmission systems are proposed.The integrated model includes the converter transformers and the converter valves.The converter transformer adopts the simplified model and the converter valve adopts the ideal switch model,which can simplify the electrical network structure of the converter.In this algorithm,the electrical network topology of converters is divided into the main network and the sub-network.First,the main network is solved,and then the subnetwork is solved according to the obtained results.Finally,the current and voltage of each converter valve in the current simulation step size are updated.The integrated electromagnetic transient simulation model and algorithm are programmed in the PSModel simulation software,and its efficiency and accuracy are verified by comparing with the PSCAD/EMTDC simulation results.