次同步谐振的机—电联合仿真方法

Electro-mechanical Co-simulation of Sub-synchronous Resonance

为了克服传统次同步谐振机电耦合仿真中仅采用简化的集中质块轴系模型而不能获取机组轴系细节扭矩动态的缺陷,设计了基于PSCAD和ANSYS软件的机—电联合仿真方法,建立了新的耦合机制,通过数据通信实现了两个软件间转速和转矩等接口信息的交换,从而可用复杂的连续质块模型替代原有的简化质块模型,使机电耦合动态分析更加完整和严谨,进而为深入的疲劳分析提供了基础数据。对印度某电厂机组出现的次同步谐振问题进行了实例分析,获得了轴系特定轴段的动态扭矩响应,验证了方法的可行性和有效性。

The critical defect of the simplified lumped mass-spring shaft model in sub-synchronous resonance(SSR)simulation study lies in that no detailed torque dynamics of the shaft can be obtained for the purpose of accurate fatigue analysis.To remedy such a situation,a co-simulation method by combining PSCAD and ANSYS is proposed and implemented.The simple shaft model with several masses in PSCAD is replaced with a complicated shaft model with several hundred masses in ANSYS,which makes the SSR study more complete and rigorous.Therefore,sufficiently detailed data are available for further fatigue analysis.Rotation speed and torque are used as the interfacing data between the two software.The data communication mechanism has been elegantly designed and implemented in order to fulfil co-simulation.With the SSR problem in an India power plant as an example,the detailed torque dynamics of specified shaft segments has been obtained and compared with the average torque provided with the simple model in PSCAD,which fully demonstrates the feasibility and effectiveness of our proposed method.