基于广域测量技术的电力系统稳定控制研究

发布时间：2018-05-17 01:10

本文选题：电力系统稳定 + 低频振荡　；参考：《浙江大学》2014年博士论文

【摘要】：随着社会的进步和时代的发展,电力行业正向着智能化阶段高速发展,系统规模日益扩大,各种新技术层出不穷。在此背景下,很多传统的控制技术已经不能满足新形势下的系统要求,因此,对传统控制理论进行完善,寻找适用于大系统并且可靠、稳定的新控制方法,促进新兴技术与传统电网融合,已经成为了电力工作者研究的几个重点问题。基于此背景,本文将以电力系统中的低频振荡和低频减载问题作为切入点,从三个主要方面进行研究：第一,本文提出了一种基于同伦算法的电力系统稳定器(PSS)参数整定方法。该方法根据控制目标不同,可以分为标准极点配置法和最小方差极点配置法两种形式,其中标准极点配置法算法效率较高,但是适用性较窄；最小方差极点配置法可以完成绝大多数的极点配置工作,但是由于涉及特征值的二阶导数,运算过程稍微复杂。本文还介绍了几种可以提高算法表现的应用技巧,如特征值追踪、控制变量重新标度、在广域PSS中的应用等。最后结合十个典型系统(其中,包含一个3296节点的华东实际系统算例),对所提出的设计思路和应用技巧进行了一一说明,验证了该方法的有效性。第二,本文提出了一种基于特征根实部表达式的PSS广义相位补偿原理。结合电力系统模型特性和此表达式,可以从新的角度解释单机无穷大系统中的负阻尼现象和PSS抑制振荡的机理。另外该式可推广至多机系统,提出了适用于多机系统的稳定判据,此判据同时可用于PSS选址和稳定器相位补偿参数设计。然后,稳定器增益整定问题被转化为一个只包含少数变量和约束条件的多项式优化问题,并介绍了基于行列式和基于特征值表达式的两种求解方法。最后,将此方法推广至广域PSS设计,对广域PSS选址和信号选择进行了分析。通过五个不同规模算例系统的分析,证明了此方法的正确性和可行性。第三,本文提出了一种基于电力系统广域测量系统(WAMS)的低频减载方案设计方法。该方法以频率响应(SFR)模型为基础,结合WAMS提供的系统状态信息,可对事故后的系统动态预测,从而在考虑系统频率动态的基本约束后,得出低频减载的优化方案。同时,本方法还考虑了发电机的输出饱和问题,在兼顾算法精度和算法效率的原则下,引入了一种“变步长隐式枚举法”作为优化算法。在与华东主网联系较弱的舟山电力系统的仿真结果表明,此方法在严重故障下具有更高的鲁棒性,并可优化一般故障下的减载量。
[Abstract]:With the progress of the society and the development of the times, the electric power industry is developing at a high speed, the scale of the system is expanding day by day, and a variety of new technologies emerge endlessly. In this context, many traditional control techniques can not meet the system requirements under the new situation. Therefore, the traditional control theory is improved to find a new control method suitable for large systems and reliable and stable. To promote the integration of emerging technologies and traditional power grids has become a few key issues for power workers. Based on this background, this paper will take the low-frequency oscillation and low-frequency load reduction in power system as the breakthrough point, and study from three main aspects: First, a homotopy algorithm is proposed for parameter tuning of power system stabilizer (PSS). This method can be divided into two forms: standard pole collocation method and minimum variance pole assignment method according to different control objectives. The standard pole assignment algorithm is more efficient, but its applicability is narrow. The minimum variance pole assignment method can accomplish most of the pole assignment work, but because of the second derivative of the eigenvalue, the operation process is a little complicated. This paper also introduces several techniques to improve the performance of the algorithm, such as eigenvalue tracking, control variable rescaling, wide area PSS applications, etc. Finally, with ten typical systems (including a 3296 node practical system in East China), the proposed design ideas and application techniques are illustrated one by one, and the effectiveness of the proposed method is verified. Secondly, this paper presents a PSS generalized phase compensation principle based on the real expression of the feature root. Combined with the characteristics of the power system model and this expression, the negative damping phenomenon in a single machine infinite bus system and the mechanism of PSS suppressing oscillation can be explained from a new point of view. In addition, the formula can be extended to the maximum machine system, and a stability criterion suitable for multi-machine systems is proposed, which can be used in the design of PSS site selection and phase compensation parameters of stabilizer at the same time. Then, the stabilizer gain tuning problem is transformed into a polynomial optimization problem with only a few variables and constraints, and two solutions based on determinant and eigenvalue expression are introduced. Finally, this method is extended to wide area PSS design, and the location and signal selection of wide area PSS are analyzed. The correctness and feasibility of this method are proved by the analysis of five different scale examples. Thirdly, this paper presents a design method of low frequency load reduction scheme based on wide area measurement system (WAMS) of power system. Based on the frequency response model and the system state information provided by WAMS, this method can predict the system dynamics after the accident, and then, after considering the basic constraints of the frequency dynamics of the system, the optimization scheme of the low frequency load reduction can be obtained. At the same time, the problem of generator output saturation is considered, and a variable step implicit enumeration method is introduced as the optimization algorithm under the principle of taking into account the accuracy and efficiency of the algorithm. The simulation results of Zhoushan power system with weak connection with the East China main network show that the proposed method is more robust and can optimize the load reduction under general faults.
【学位授予单位】：浙江大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TM712

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