计及状态估计与可观性的电力系统可靠性评估

Power System Reliability Assessment Considering State Estimation and Observability

当前"泛在电力物联网"的建设加速推进,电力系统在多个层面上展现出电力-信息互联互通、状态全面感知的趋势,给电力系统可靠性评估的建模和分析带来了新的挑战。结合感知终端层的测量信息对电网感知能力的支撑作用,提出一种全面的电力系统可靠性模型,深入研究了广域测量系统、状态估计与电网调度之间的电力-信息交互机理。在电网调度模型中,定量考虑广域测量系统不同程度故障下实际量测信息的变化对可观性的影响;引入状态估计补充缺损量测信息,以改善调度决策、提升电力系统可靠性。在此基础上,提出了一种计及状态估计和可观性影响的电力系统可靠性评估方法。算例验证表明,所提模型和方法可以准确刻画可观性变化及状态估计对电力系统可靠性评估的影响;结合典型故障场景,进一步分析了状态估计对于可靠性提升的有效性和实用性。

With comprehensive cyber-power integration and state awareness shown on various levels, the concept of "ubiquitous power internet of things" emerges and brings new challenges to power system reliability assessment. This paper studies the cyber-power integration mechanism incorporating wide-area measurement systems, state estimation and power dispatching. The impact of measurements and observability are quantitatively considered with wide-area measurement system in dispatching model, and state estimation is employed as the supplement to lost measurements, improving power system dispatching decision and reliability. On this basis, a reliability model considering state estimation and observability are proposed. Case study shows that the proposed model and algorithm can accurately describe the impact of observability and state estimation on reliability. Validity and practicability of state estimation for reliability improvement is further analyzed based on typical fault scenarios.