Status estimating method for dynamic process of electrical power system

Abstract

The invention provides a method for estimating a state of dynamic process of a power system. The method takes an estimated result of the static state before the electric grid disturbance as a basic section and introduces a load model and a motor model to perform the equivalent treatment to the electric grid; in the process of the electric grid disturbance, a synchronous phasor measuring unit(PMU)is used to measure and obtain data of a motor, and according to the active power and the reactive power zero injection pseudo-measurement equations of all nodes of the original electric grid, states ofall nodes of the electric grid are estimated, and the state of dynamic process of the electric grid is acquired only by the PMU measurement of a power plant. Because the state of the electric grid be fore disturbance is taken as a basis and only the PMU distribution of the power plant is required, the method effectively resolves the problem of state monitoring under the condition of the electricgrid disturbance; on the same disturbance, for continuous PMU measurement sections, PMU measurement data can be directly put in iterative computations, thereby the continuous sections in the process of electric grid disturbance are provided for stable control and analysis; moreover, the method is fast in speed, so that the method meets the requirement for monitoring the dynamic process in real time.

Description

technical field [0001] The present invention relates to a method for state estimation using a power system synchrophasor measurement unit PMU (Phasor Measurement Unit). estimate. Background technique [0002] In most cases, the power grid is in a stable state, and the load change is a slow process. Although the measurements in the EMS are not collected at the same time, due to the slow change of the actual power grid, the error generated by the collection time is relatively large compared with the meter error. Small, so it can be considered that the collection is the same time section of the power grid. Static state estimation is calculated for a complete power grid state, which can meet the needs of monitoring and control in the normal operation mode of the power grid. [0003] Under the disturbance condition of the power grid, the power flow of the system has shifted, and the system is in the process of changing. At this time, the error caused by the asynchrony of the me...

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Problems solved by technology

[0007] The problem to be solved by the present invention is: when the power grid is disturbed, the conventional RTU measurement cannot reflect the complete operating state of the power grid within a period of time, and the power grid during the disturbance process cannot be effectively monitored due to the inability to obtain the complete state of the power grid during the disturbance process. Although PMU measurement can obtain the continuous change process of voltage, power, and phase angle during the disturbance process, there are not many PMU measurement points at present, which cannot directly meet the observability requirements of power grid state estimation

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