[关键词]
[摘要]
对于异步联网系统中网架结构比较薄弱的省网系统或者系统解列后形成的孤岛,发生故障时会引起比较大的频率波动,在此情况下对感应电动机进行建模时考虑其频率特性尤为重要。基于感应电动机一阶机械暂态模型,利用解析法分别推导出不同负载特性下稳态及动态转差率关于系统频率的表达式,并在此基础上计算吸收的有功功率和无功功率,进而分析感应电动机的功率频率特性。在MATLAB中建立感应电动机五阶电磁暂态仿真模型,仿真分析不同负载特性感应电动机的功率频率特性。仿真结果与理论推导结果吻合,验证了在简化模型下推导得到的感应电动机频率特性解析式的正确性和有效性。
[Key word]
[Abstract]
A larger frequency fluctuation will be caused when fault occurs in the power systems where the grid structure is relatively weak or isolated islands are formed after system splitting in asynchronous networking system. In this case, it is was very important to consider the frequency characteristics of the induction motor when it is modeled. Based on the first order of mechanical transient model of the induction motor, the expression of steady and dynamic state slip ratio of the system frequency under different load characteristics by analytical method was deduced. On this basis, the absorbed active power and reactive power were derived, and then the powerfrequency characteristics of the induction motor were analyzed. The fifthorder electromagnetic transient simulation model of induction motor was established in MATLAB simulation software to simulate and analyze the powerfrequency characteristics of induction motors with different load characteristics. The simulation result was consistent with the theoretical derivation, so it was correct and effective to deduce the frequency characteristics of an induction motor under the simplified model.
[中图分类号]
TM 346
[基金项目]
国家自然科学基金项目(51367009)