大规模风电并网对送端系统功角稳定的影响研究

随着我国风电能源的不断发展，大规模风电集中接入电网对送端系统暂态功角稳定的影响问题仍然不容忽视。以双馈型风电集中接入受端大系统为分析对象建立等效模型，并基于双馈风机的功角特性和暂态特性展开分析。首先，采用单端送电系统同步机的电磁功率解析表达式，通过分析风电等出力置换火电出力接入系统对电磁功率方程的影响推断出风电接入对同步机初始功角的影响。其次，通过负负荷接入与风电接入两种接入方式的对比分析了双馈风机在故障发生后有功功率和无功功率特性对同步机电磁功率方程的影响，并基于等面积定则(EAC)分析了双馈风机接入对系统暂态功角稳定性的影响。研究结果表明，风电等出力置换火电出力时同步机初始功角减小，暂态稳定性升高；双馈风机的有功功率和无功功率特性对系统暂态功角稳定性具有正向作用。最后，通过仿真验证了理论的正确性，并在实际电网中得到了验证。

Influence of large-scale wind power grid connection on the power angle stability of the sending end system

With the continuous increase of the scale of wind power in China, it is important to look at the mechanism of the influence of large-scale wind power centralized access to the power grid on the transient power angle stability of the transmission system. An equivalent model is established as the research object for the centralized connection of the doubly-fed wind power to the large receiving end system. The analysis is carried out based on the transient characteristics and low voltage ride-through characteristics of the doubly-fed wind turbine. First, we adopt the electromagnetic power analysis expression of the synchronous machine of the single-ended power transmission system, and infer the influence of wind power connection on the initial power angle of the synchronous machine by analyzing the influence of wind power equivalent output replacement thermal power access system on the electromagnetic power equation. Secondly, through the comparison of the two access methods of negative load and wind power access, the influence of the active power and reactive power characteristics of the doubly-fed wind turbine on the electromagnetic power equation of the synchronous machine after the fault occurs is analyzed. Based on the equal area rule (EAC), the influence of the doubly-fed fan connection on the system transient power angle stability is analyzed. The results show that when wind power is equivalent to replacing thermal power output, the initial power angle of the synchronous machine decreases, and the transient stability increases; the active power and reactive power characteristics of the doubly-fed fan have a positive effect on the transient power angle stability of the system. Finally, the correctness of the theory is verified by simulation, and it is verified in the actual power grid. This work is supported by the Science and Technology Project of the Headquarters of State Grid Corporation of China (No. 5100-202116005A-0-0-00).