Power system state estimation method based on phasor measurement

Abstract

The invention relates to a power system state estimation method based on phasor measurement, and belongs to the technical field of power system operation and control. The method comprises the steps that a complex number measurement equation based on full PMU measurement is set up in a complex number field, a measurement quantity and a state quantity in the measurement equation are in a linear relation, meanwhile, an optimized objective function is directly set up for an overdetermination measurement equation in the complex number field, the measurement equation is solved through a complex number relative least-square method, and therefore state estimation and computation based on the full PMU measurement are directly completed in the complex number field. According to the method, power system state estimation is expanded to the complex number field from a real number field, and the state estimation result can be directly obtained through one-time computation. Due to the fact that the complex number method is adopted, high robustness is achieved on phase angle errors, algorithm efficiency is high, meanwhile, the self-weighting effect of the least square method is considered, and therefore the accuracy of power system state estimation is improved.

Description

technical field [0001] The invention relates to a method for estimating the state of a power system based on phasor measurement, and belongs to the technical field of power system operation and control. Background technique [0002] In recent years, with the rapid deployment of phasor measurement units (Phasor Measurement Unit, hereinafter referred to as PMU) in the power grid, a large number of phasor measurements provide new data for power system analysis and calculation. However, compared with active power measurement, the accuracy of PMU phase angle measurement is not enough, and due to network communication interruption, measurement equipment failure, etc., there may be bad data in PMU measurement. At the same time, the PMU installed in the power grid at this stage , and its measurement accuracy is not very satisfactory. Therefore, the PMU measurement data cannot be used directly, and the state estimation based on the full PMU measurement is necessary. [0003] At pre...

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Problems solved by technology

However, this method introduces conversion errors when converting the phasor into real and imaginary parts; and ignores the correlation between the real and imaginary parts of the same phasor; in addition, after the phasor is converted into real and imaginary parts, the coefficient matrix The scale increases, which increases the amount of calculation; at the same time, the method is not robust to phase angle errors

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