【作者】 蒋正威；

【导师】 曹一家；

【作者基本信息】 浙江大学 ， 电气工程， 2008， 硕士

【摘要】 基于同步相量测量技术的广域测量系统在电力系统动态监测、系统建模、模型校核、广域保护和控制方面有着重要的应用价值,也吸引着越来越多人的兴趣。显然,在全网所有母线配置PMU就能进行线性状态估计而不需要迭代,因此计算速度快且无收敛问题。然而考虑到PMU量测的特点及安装费用的约束:在测量电压相量的同时还能测量关联线路的电流相量,因此只需在全网1/5到1/3的母线上配置PMU即可实现全网完全可观测并进行线性状态估计。故在满足特定约束条件下如何以最少数目的PMU实现全网完全可观测,成为了广域测量技术的一个研究重点。本文首先介绍了WAMS系统的架构、应用、基于PMU量测的线性状态估计,然后回顾了现有的满足全网可观测和满足特定应用约束条件的PMU配置方法。分析表明这些方法并不能完全满足实际工程的需求。为解决这一问题,本文提出了PMU配置论域的概念。利用这个概念,可以简化PMU的配置复杂性以及增强配置方法的灵活性。通过改变论域还能使配置结果具有一定的抵御高风险连锁故障的能力。随后,本文提出了基于0-1线性整数规划的能灵活满足多种约束条件的通用PMU配置方法。在此基础上首先针对高压电网中不存在零注入节点的实际情况,提出了一种能够考虑线路N-1和PMU装置N-1的PMU最优配置方法。其次考虑到一般电网中存在的零注入节点会导致模型的高度非线性并且会显著增加PMU配置的复杂度。该方法通过将零注入节点转化为潮流已知线路巧妙地解决了这个问题。最后针对实际工程中分阶段配置PMU的需求,定义了不可观测深度的概念并结合此概念提出了一种能够考虑分阶段配置PMU的最优配置方法。利用该方法,很容易制定实施计划。上述配置模型具有统一的形式,即0-1线性整数规划模型,并且能够处理诸如通信限制、已安装PMU、某些设备需要直接监视之类的约束。通过在IEEE系统、新英格系统、浙江实际电网的仿真计算,表明上述方法灵活而高效。更多还原

【Abstract】 Wide Area Measurement System (WAMS) based on synchronized phasor measurement technology has been gaining increasingly interests due to its great value in power system dynamic monitoring, potential applications in system modeling and validation and system wide protection and control. The wide installation of PMU at every bus will lead to a simplified linear state estimation which provides faster calculation speed and higher numerical stability. But due to the cost limitation and the fact that each PMU can measure not only the bus voltage but also the currents along all the lines incident to the bus, only 1/5 to 1/3 buses in the grid need to be equipped with PMUs to make the entire system observable. Hence, how to make the entire system observable with minimal numbers of PMUs while fulfilling certain constraints becomes a hotspot in the field of WAMS.Firstly the architecture and applications of WAMS and linear state estimation based on PMUs measurement are introduced. And then the current status of optimal PMU placement methods considering the observability of the entire system or some other constraints is reviewed. Analysis and comparison shows that current optimal PMU placement methods are not fully satisfied with the practical needs. This paper presents the notion of PMU placement domain. Using the idea of domain, the PMU placement problem can be simplified and become more flexible. The placement scheme has the ability to resist high risk cascading failure in power grid by varying the domain. And then a flexible optimal PMU placement algorithm based on 0-1 linear integer problem is proposed. Considering the fact that zero injection node is not existed in high voltage power grid, an optimal PMU placement method accounting for cases of any line tripped or loss of a single PMU is provided firstly. Taking the zero injection node into consideration greatly increase the complexity and nonlinearity of PMU placement. This method overcomes this problem by converting the zero injection nodes into branches with known power flow. Finally, the conception of depth of unobservability is defined and an optimal PMU placement algorithm accounting for multi-stage installation is proposed. Using this method, installation scheduling can easily be made.All of the PMU placement methods mentioned above are modeled with 0-1 linear integer program and can account for multi-constraints, such as the restriction of communication conditions, the installed PMUs, the requirement of direct monitoring some critical infrastructures and so on. These methods are validated by IEEE system, New England system and Zhejiang power grid. The effectiveness and flexibility of the proposed algorithms are justified by the simulation results.更多还原