含风电场的多直流送出电网电磁暂态仿真建模

摘要

为准确分析含风电场的多直流送出的新型电网继电保护和谐波特性问题，针对宁夏电网宁东-浙江特高压直流输电投运后的2016年冬大运行方式，给出了基于PSCAD/EMTDC建立其电磁暂态仿真模型的方法。根据宁夏电网的特点，将仿真模型进行模块划分和接口定义，将整个电网划分为交流电网、风力发电和直流输电三大独立模块，定义了各模块之间的接口。分别对三大模块进行详细建模，给出了交流电网建模的分层分块原则。通过模块之间的接口将模块连接，构成宁夏电网全网的电磁暂态仿真模型。将仿真模型的稳态运行以及短路电流仿真结果与PSASP的计算结果比较，验证了模型的正确性。仿真结果表明，电磁暂态仿真模型能详细分析风电场和多回直流输电系统的暂态响应特性，能准确反映含风电场的多直流送出电网运行特性和故障特性，对研究该类型新型电网的继电保护和谐波传递问题具有重要意义。%In order to analyze the problems of protections and harmonics in the multi-send HVDC system with wind plants, which is a novel power grid, an approach to establish the electromagnetic transient simulation model by PSCAD/EMTDC is presented. After the ±800 kV Ningdong-Zhejiang UHVDC is put into operation, Ningxia grid will be this novel power grid. The winter peak operation mode of Ningxia grid in 2016 is studied. The simulation model is divided into three modules: AC grid, HVDC systems and wind plants. The interfaces between modules are defined. The simulation models of three modules can be established independently. The principle to divide the AC grid into different levels and modules is presented. With interfaces defined, the whole Ningxia grid is connected with the modules. The simulation results of the static performances and fault currents are compared with PSASP, and the validness of the simulation model is testified. The simulation results show that the transient performance of the wind power plants and HVDC/UHVDC can be analyzed in detail. The electromagnetic transient simulation model of the grid is very important to study the problems of protections and harmonics in such grid.