【作者】 赵伟；

【导师】 曹一家； 江全元；

【作者基本信息】 浙江大学 ， 电力系统及其自动化， 2010， 硕士

【摘要】 随着我国“智能电网”战略的实施以及特高压、大电网互联格局的形成,电网的安全和稳定运行面临着新的挑战,为了遏制大面积停电事故的发生和演化,需要一种快速、准确的故障诊断和故障定位技术来为电网安全保驾护航。同时,基于同步相量测量技术的广域测量系统已经在电力系统中得到了成功应用,并为电网故障诊断提供了新的信息渠道,在这样的背景下,本文开展了基于广域测量系统的电网故障诊断方法研究。主要工作内容和研究成果如下:首先,通过比较监控与数据采集系统(SCADA)和广域测量系统(WAMS)的特性,指出了基于同步相量测量技术的广域测量系统在电力系统中的应用前景;通过综述现有故障诊断方法的优劣,提出了基于广域测量系统的电网故障诊断方法研究的可行性和必要性。其次,针对基于开关量的故障信息存在误动、拒动等不确定性以及本身开关量存在错误概率的问题,提出了基于电网潮流指纹的故障诊断方法;同时,文中还提出了利用改进整数规划模型的PMU优化配置方法。该诊断方法只需获得指纹特征点处电气量数据,信息需求量小,实时性强,避免了开关量信息不确定性对电网故障诊断的影响。再次,针对基于SCADA的故障信息具有局部性和实时性较差的问题,本文采用PMU作为故障信息源。与此同时,由于传统故障诊断方法中存在专家知识库、训练样本集等难以满足完备性的问题,本文提出了基于PMU和信息融合技术的电网故障诊断方法。该方法有效实现了基于开关量故障诊断和电气量故障诊断的决策层融合,实时性高,能够把握连锁故障本质,同时在一定程度上弥补了传统故障诊断的不足。最后,作为故障诊断领域的进一步研究,本文提出了一种仅利用线路两端电压相量实现电力传输网故障定位的方法。其中,提出了用于故障定位的电压相量平衡指标,通过遍历搜索方法实现故障定位。该方法信息需求量小;同时避免了电流互感器饱和现象和过渡电阻对故障定位精度的影响。更多还原

【Abstract】 As the development strategy of "Strong Smart Grid" is being carried out; and at the same time the Ultra High Voltage Transmission and Large-scale Interconnected Power Grid come into formation, new challenges on the integration and stability of power grid have been under concern. New technologies, such as fast and accurate fault diagnosis and location are possible to be used to prevent the occurrence and expansion of blackouts. Besides, the Phasor Measurement Units (PMUs) based Wide Area Measurement Systems (WAMS) have been successfully implemented in power systems, which also provides a measurement and communication channel for power grid fault diagnosis. Under this situation, this thesis has studied the WAMS-based methods for power grid fault diagnosis. The main work of this thesis is stated as follows.Firstly, by comparison between WAMS the conventionally applied SCADA system, the potential of WAMS to be implemented in power system has been highlighted; and the feasibility and necessity of applying WAMS into power grid fault diagnosis has been concluded by analyzing the characteristics of current fault diagnosis methods.Secondly, the key work of this thesis--the power flow fingerprint based fault diagnosis method is proposed in order to overcome the current problems in fault diagnosis algorithms, for example, the uncertain mis-operation and loss-operation caused by the inaccurate fault information of switching signals, and the existing probability for switching signals to have errors. This diagnosis method only needs the electrical data of finger-print nodes, which decreases the requirement of information, and at the same time increases the real time characteristic and avoids much of the influence of the uncertainty of switching information to the results of fault diagnosis. Meanwhile, the thesis has proposed the optimal placement method by using the improved integer programming.Thirdly, PMUs are used as the measurement units to provide data from wide-area, and with high accuracy and updating rates, which is an improvement of the locally characterized faulty information from SCADA. Information Fusion Technology (IFT) is introduced to process the data from PMUs. In the decision level, by IFT the switching signals based fault diagnosis and electrical signals based diagnosis have been combined to improve the real time character and the ability to capture the identity of cascading failures.Fourthly, as the further study on fault diagnosis, in this thesis, a power grid fault location method which only needs the phasors of terminal voltages in one transmission line is proposed. A voltage phasor balancing standard is proposed as the decision criteria for fault location and the Traversal Searching method is used for searching the optimal decision of the fault location. The fault location method proposed here requires small amount of information and can at the same time avoid the impacts from current transformer saturation and Transition Resistance to the accuracy of fault location results.更多还原