Transient voltage stable on-line assessment method based on WAMS and EMS

Abstract

The invention relates to a transient voltage stable on-line assessment method based on a WAMS (Wide Area Measurement System) and an EMS, comprising: obtaining WAMS real-time power grid measurement information to determine whether a power grid is disturbed; obtaining the topological structure, parameters and power flow operation information of a current power grid from an EMS when the power grid is disturbed so as to calculate a full admittance matrix concerning load equivalent admittance; according to the WAMS measurement information, running statistics on nodes having a voltage dip exceeding a preset threshold value, obtaining Thevenin equivalent parameters of statistic nodes based on full admittance matrix inversion to be used as an initial value to track Thevenin equivalent parameter identification of the WAMS measurement information and static state voltage stable margin index calculation, and calculating a transient voltage dip acceptability area index; and running statistics on nodes having a power grid node voltage dip exceeding a preset threshold value and having a dip duration greater than a preset threshold value, and determining the occupancy of power grid disturbance transient voltage instability nodes. The method can rapidly and effectively realize the stable and rapid assessment of a transient voltage.

Description

Technical field: [0001] The invention relates to a method for evaluating the operating state of a power grid, and more particularly to an online evaluation method for transient voltage stability of a receiving power grid based on WAMS and EMS. Background technique: [0002] With the rapid development of society, economy and power industry, the power grid has gradually developed into a large-scale, long-distance, UHV AC-DC interconnection and an increased proportion of new energy access, which increases the uncertainty of power grid operation. The receiving-end power grid is mainly centered on the load-concentrated area, and is connected to the long-distance generalized originating power supply through the surrounding tie-lines, so as to achieve the balance between supply and demand of electric energy. Due to the mismatch between the distribution of energy and the load center area, as well as the consideration of factors such as the environment, the internal power supply supp...

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Problems solved by technology

However, there are few studies on transient voltage stability assessment based on WAMS measurement information, and the empirical binary table method of acceptable time for voltage dips is often used. The binary table method cannot give a clear evaluation of the transient voltage stability margin. information

In addition, the existing WAMS system often only realizes the measurement status information of the independent power grid components installed at the PMU site, lacks information such as the topology of the entire network, and due to the limited number of PMU installations, a WAMS and EMS-based On-line evaluation method of transient voltage stability of receiving end power grid to overcome the above shortcomings

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