基于二维一阶伴随系统的电网暂态稳定在线分析与控制

发布时间：2018-01-04 13:34

  本文关键词：基于二维一阶伴随系统的电网暂态稳定在线分析与控制　出处：《天津大学》2014年博士论文　论文类型：学位论文

  更多相关文章： 电力系统 广域测量系统 暂态稳定 功角稳定 暂态能量函数 紧急控制

【摘要】：随着我国大规模交直流混联电力系统的不断建设和发展,依靠离线数据或者SCADA/EMS数据实现暂态稳定分析与控制的方法,已经难以满足实际电网的运行需求。而广域测量系统(WAMS)的投入使用,为暂态稳定分析和控制带来了新技术手段。本文提出了将二维一阶伴随系统理论与WAMS实时数据相结合,实现暂态稳定分析与紧急控制的新思路。论文首先系统地介绍了二维一阶伴随系统的理论基础,并分析了其基于WAMS系统实现稳定性分析的适用性。在此基础上,提出了基于数值微分求导方法的二维一阶伴随系统的在线计算方法,以及在线暂态稳定分析与紧急控制的实现架构,为后文工作提供了理论依据和计算方法。提出了将二维一阶伴随系统和WAMS系统相结合的暂态稳定在线识别方法。该方法定义考虑多摆稳定的最小投影动能,并提出对应的暂态稳定判据。为了给紧急控制系统预留更多的时间,提出利用最小二乘拟合技术预测系统轨迹并进行稳定性预判。所提方法不受系统模型参数和网络拓扑影响,无需识别临界机群和计算故障后系统稳定平衡点,仅需采集发电机运行数据即可进行稳定性判别。建立了伴随凹轨道系统的数学模型,并利用该系统提出了暂态稳定性在线识别的新方法。基于微分几何学的曲率概念实现在线监测系统运行点和预测稳定边界,在此基础上提出了失稳预测判据。该系统与二维一阶伴随系统互为映射,因此,具备其在稳定性分析中的诸多优点。此外,该方法在预测边界时能避免因回摆点附近强非线性而导致预测失效的问题,并且无需调节观测和预测窗口。提出了一种电力系统暂态稳定性在线分析的分区-合成方法,并设计了利用WAMS数据实现大电网分层分区在线监控的系统框架。利用所提分区-合成理论,各区域系统仅需传递二维一阶伴随系统的特征量即可实现快速、准确判断全系统的暂态稳定性。因此,所提方法能够有效提高实际系统稳定分析数据的传输效率并降低系统数据的存储空间。提出了基于伴随凹轨道系统的电力系统实时闭环紧急控制方法。该方法利用发电机组失稳排序指标选取失稳机组,基于凹轨道失稳裕度来估计紧急控制切机量。所提方法能够在不依赖离线故障策略表的条件下实现在线紧急控制,此外,该方法将失稳机群识别和稳定性判别过程相解耦,提高了实时紧急控制策略在实际电力系统中的计算效率和实用性。
[Abstract]:With the continuous construction and development of large-scale AC / DC hybrid power systems in China, transient stability analysis and control methods depend on off-line data or SCADA/EMS data. It has been difficult to meet the operational requirements of the actual power grid, and WAMS (wide area Measurement system) has been put into use. This paper presents a new technique for transient stability analysis and control. In this paper, the theory of two-dimensional first-order adjoint system is combined with WAMS real-time data. A new approach to transient stability analysis and emergency control is presented. Firstly, the theoretical basis of two-dimensional first-order adjoint system is systematically introduced. The applicability of stability analysis based on WAMS system is analyzed. Based on this, an on-line calculation method of two-dimensional first-order adjoint system based on numerical differential derivation method is proposed. And the implementation framework of on-line transient stability analysis and emergency control. This paper provides the theoretical basis and calculation method for the later work. A method of on-line transient stability identification is proposed, which combines two-dimensional first-order adjoint system with WAMS system. This method defines the minimum projective kinetic energy considering multi-pendulum stability. . The corresponding transient stability criterion is proposed to reserve more time for the emergency control system. The least square fitting technique is used to predict the trajectory of the system and to predict the stability of the system. The proposed method is independent of the system model parameters and network topology, and does not need to identify critical cluster and calculate the stable equilibrium point of the system after failure. Only the generator operation data can be collected to judge the stability, and the mathematical model of the system with concave track is established. Based on the curvature concept of differential geometry, the on-line monitoring system running point and predicting stability boundary are realized. On this basis, the instability prediction criterion is proposed. The system is mapped to two-dimensional first-order adjoint system, so it has many advantages in stability analysis. This method can avoid the problem of prediction failure caused by strong nonlinearity near the return pendulum point when predicting the boundary. Without adjusting the observation and prediction window, a zone-composition method for on-line analysis of power system transient stability is proposed. And design the system frame of using the WAMS data to realize the on-line monitoring and control of the large power network, and use the theory of zonation and composition mentioned above. Each region system only needs to transfer the characteristic quantity of 2-D first-order adjoint system to realize fast and accurately judge the transient stability of the whole system. The proposed method can effectively improve the transmission efficiency of system stability analysis data and reduce the storage space of system data. A real-time closed-loop emergency control method for power system based on concave track system is proposed. The unstable unit is selected by using the unsteady ranking index of the generator set. The proposed method can realize the on-line emergency control without relying on the off-line fault policy table based on the stability margin of the concave track. The method decouples the identification of unstable cluster and the stability identification process, and improves the calculation efficiency and practicability of real-time emergency control strategy in practical power system.
【学位授予单位】：天津大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TM712
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本文编号：1378752