All-PMU (phase measurement unit)-orientated robust state estimation method

Abstract

The invention discloses an all-PMU (phase measurement unit)-orientated robust state estimation method comprising the following steps of: initializing a network topology model and network parameters of a power system, and updating a switch measurement value and a PMU measurement value; performing topological contraction and measurement matching; identifying the range of observable nodes; performing equivalent measurement transformation; and establishing a state estimation model and solving. According to the all-PMU-orientated robust state estimation method disclosed by the invention, the convergence rate, the qualification rate and the calculation frequency of a state estimation system are remarkably improved, the maintenance workload of the state estimation system is greatly reduced, and the foundation is laid for rapid sensing, comprehensive sensing and accurate sensing for a power grid. The robust state estimation method disclosed by the invention has remarkable improvement on the aspects of calculation accuracy, calculation speed and convergence rate compared with the existing methods.

Description

technical field [0001] The invention relates to the technical field of power system analysis and control, in particular to a robust state estimation method for full PMU measurement. Background technique [0002] Power system state estimation was proposed by F.C.Schweppe in the early 1970s. Its main task is to use the redundancy of the real-time measurement system, apply estimation algorithms to detect and eliminate bad data, automatically eliminate error information caused by random interference, and improve data quality. Accuracy and consistency, in order to estimate or forecast the operating status of the system, and provide credible real-time power flow data for network analysis. After decades of development, power system state estimation, as the data basis for power grid analysis and control, has become an important part of energy management systems and the core and cornerstone of advanced applications in power systems. However, the existing state estimation system cann...

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Problems solved by technology

If only phasor measurement is used, the measurement equation is a linear equation in the Cartesian coordinate system, and the corresponding state estimation model will also be simplified to a certain extent, but at this time the measurement redundancy is relatively low, and the estimation results will be overly dependent on The accuracy and stability of the measurement, but in actual operation, it is found that the phase angle measurement value is an absolute phase angle value, which fluctuates greatly, and the time synchronization error of the millisecond level may cause fluctuations in the phase angle measurement, which is equivalent to The power can reach MW level, that is to say, the accuracy and stability of phase angle measurement cannot be guaranteed. Therefore, it is necessary to add branch power measurement and node injection power measurement to the state estimation model to improve the measurement performance. Redundancy, in order to obtain high confidence estimation results

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