【作者】 陆丹丹；

【导师】 王建全；

【作者基本信息】 浙江大学 ， 电气工程， 2012， 硕士

【摘要】 随着我国电力系统的快速发展,安全问题越来越突出,在线稳定分析也成为实现电力系统安全稳定运行与控制的重要手段之一。快速预想事故筛选作为电力系统动态安全分析的重要组成功能,是一个很有研究价值的课题。本文围绕在线动态安全分析中基于时域仿真的事故扫描展开了研究。要达到快速性和准确性的统一是基于时域仿真的暂态稳定分析研究中的难点。为提高快速性,本文提出了一种基于二阶发电机模型的显式数值积分快速时域仿真法,其采用显式二阶单步积分的发电机转子运动方程,与传统的显式欧拉法相比,截断误差更小,而速度更快,同时,根据二阶发电机模型的特点,改变了传统的交替迭代求解微分-代数方程的计算流程,使得每一时步只需求解一次微分-代数方程,从而提高了暂态稳定计算速度。然后,针对传统的角度判别准则需要的大量的数值积分时步的问题,提出了一种暂态稳定判据,其采用SIME辨识方法,实现多机系统到单机无穷大系统的映射,并以EAC法则作为电力系统是否稳定的判据,实际系统仿真表明,采用该判据的时域仿真所需的时步大大减少,从而提高了暂态稳定计算速度。最后,根据简单发电机模型下求解网络矩阵的计算量会大大降低的特点,本文提出了基于简单发电机模型的快速预想事故筛选法,即在发电机采用E’电势恒定模型的基础上,通过改变动态负荷模型中恒阻抗模型和感应电动机模型的组合比例,来拟合发电机6阶模型和静负荷模型组合下的暂态稳定计算,以及采用E’q电势恒定的发电机模型,通过改变角度法则中的角度条件进行快速预想事故筛选的方法。更多还原

【Abstract】 With the rapid developing of the power system, the security of power system is becoming more and more important, as a result, the online stability analysis has become one of the most important means for the system security operation. Contingency screening, as an important part of dynamic security analysis, has been a very valuable subject.The paper studies the contingency screening based on time-domain simulation, by which, the difficult part is that the solution needs fast computation speed and accuracy of both. For this purpose, a fast transient stability time-domain simulation applying Explicit integration algorithm method is proposed, which is based on Second order generator model. Compared with the traditional Euler explicit integration algorithm, the method presented here can reduce the computation time, and with small truncation errors. According to the characteristics of Second order generator model, the method proposed here changes the solving procedure based on Alternating iterative method, and only need to solve the differential-algebraic equations once at each step, by which,the calculation time can be reduced. Then, In order to reduce the simulation steps needed during the transient stability computation, a transient stability criterion based on SIME is researched. The method described here replaces a multi-machine power system by an one-machine system, terminates the simulation by EAC, at the meantime, identify the unstable and stable OMIB trajectories. The simulations based on the real system testify its effectiveness. At last, the paper presents a contingency screening method based on simple generator model to reduce the computation of the network equation solving. First, It combines dynamic load models and the fixed E’generator model, to simulate the transient stability calculation based on accurate generator models and static load models, by adjusting the proportions of the induction motor load and the constant impedance load in dynamic load models, second, based on the fixed E’q generator model, through setting the angle of the angle criteria to conduct fast contingency screening.更多还原