本文基于我国广域监控系统的实际需要，针对同步相量测量技术的研究现状及问题，从时钟源的持续可靠性、相量测量的精确性、功能的完备性和装置的易扩展性等方面进行了系统深入的研究并提出了解决方法，为电力系统的广域监测、分析与控制提供技术基础。针对作为同步相量测量基本保障的同步时钟源的可靠性和可依赖性问题，研究了我国自主的“北斗一号”卫星导航系统在同步相量测量领域的可用性，并与现阶段广泛应用的GPS同步时钟源进行了对比测试。进而，提出了北斗与GPS互备授时算法，设计并实现了互备授时单元，能够提供持续可靠的高精度同步时钟，弥补了长久以来使用GPS作为唯一同步时钟源而存在的风险性和不可依赖性。深入探讨了频偏对相量测量精度的影响以及广域测量对时标再同步的要求，分析了频率自适应采样方法在广域测量领域应用的局限性。在此基础上，研究并提出了基于定间隔采样的相量校正算法，它既可消除存在频偏时DFT的频谱泄漏误差，又易于满足时标再同步的要求。工程实用结果验证了算法的实用性。阐明了绝对内电势角的概念，在分析现有功角测量方法不足的基础上，提出一种绝对内电势角直接测量的光电感应方法，可避免传统直接法固有的机端电压过零整形误差。该方法不受电气量变化的影响，在稳态和暂态过程中都能获得高精度的测量结果。针对系统中仍有不少发电机尚无转子位置传感器的实际情况，提出一种改善暂态过程内电势角估算精度的电气测量方法。以派克方程模型为基础，通过对次暂态过程的合理简化，并利用转速差积分补偿扰动初期及次暂态过程中的计算误差，能够提高扰动过程中内电势角的估算精度。设计并实现了基于北斗与GPS互备授时的分布式PMU。分布式体系结构增强了装置配置的灵活性、可扩展能力和容错性。
Based on the practical requirements of wide-area measurement systems (WAMS) in China, systematic studies are conducted in this thesis regarding the key problems of reliability of synchronization clock, accuracy of phasor measurement and expansibility of phasor measurement unit (PMU). The corresponding solutions are presented, which establish the foundations for the synchronous supervision, analysis and control in wide area power system.In order to enhance the dependability of synchronization clock, the basic elements for synchronized phasor measurement (SPM), the feasibility of applying Beidou navigation satellite system to SPM for native power system is studied and the performances of synchronization clock between Beidou and GPS are compared. Subsequently, a more accurate and reliable algorithm employing both Beidou and GPS to generate integrated synchronization clock is proposed. It minimizes the risk and undependability of using GPS as the only source of synchronization clock.This thesis investigates the influences of frequency offset upon the recursive DFT and the requirements of data resynchronization for time tags. The limitation of applying the adaptive sampling interval technique to wide area measurement is analyzed. Then an improved phasor computation method is proposed, which is based on the fixed sampling interval technique. This method not only easily satisfies the demands of time tags of data resynchronization, but also succeeds in correcting the errors caused by DFT in the presence of frequency offset. Its advantages are well demonstrated by the results from field applications.The concept of absolute internal voltage angle is presented, based on which, the drawbacks of traditional methods of measuring power angle is analyzed and a direct method using rotor position sensor is proposed. This method overcomes the errors of the traditional methods arising in detecting the level crossing of terminal voltage and is independent of electric parameters. With the method, the accurate measurement in both steady and transient conditions can be achieved.A novel approach, which is suitable for generators without rotor position sensor, is proposed to estimate the absolute internal voltage angle. Based on Park equations of generators, with reasonable simplifications of model in subtransient state and correcting estimation errors in disturbance by integration of rotor speed deviation, the proposed approach can improve the measuring accuracy in transient conditions.With all the researches and experiments being carried out, a distributed PMU based on backup synchronization clock from both Beidou and GPS is designed and implemented. With the distributed architecture, the PMU is more flexible, expansible and robust.
