Transformer parameter online calculation method

Abstract

The invention provides a transformer parameter online calculation method which is characterized by specifically comprising the following steps: 1) establishing a T-shaped equivalent circuit model according to a transformer circuit structure; 2) constructing a target function J which includes a voltage loop equation, an active loss equation, an input impedance equation, a no-load current equation and a no-load loss equation and is used for solving the high-voltage side resistance R1, the high-voltage side leakage reactance X1, the low-voltage side resistance reduction value R2 ', the low-voltage side leakage reactance reduction value X2', the excitation resistance Rm and the excitation reactance Xm, 3) taking the above formula J as a target function, and selecting an optimization algorithmfor optimization calculation to obtain an optimal solution of R1, X1, R2 ', X2', Rm and X3. According to the transformer parameter online calculation method, electrical measurement data during steady-state operation of the transformer are utilized, transformer equivalent circuit parameters such as winding resistance, leakage reactance and equivalent excitation branch impedance can be calculated and identified online, and the transformer parameter online calculation method has the advantages of small identification error and high precision.

Description

technical field [0001] The invention belongs to the technical field of transformer operation monitoring, and in particular relates to an online calculation method for transformer parameters. Background technique [0002] The operation status of the transformer directly affects the safety and stability of the power equipment and even the entire power grid. The existing transformer equivalent circuit parameter identification method mainly establishes the parameter identification model based on the voltage loop equation, and uses the least square method to complete the parameter identification. For example, Chinese patent CN201610050892.5 discloses a method for measuring leakage inductance and DC resistance of a transformer, which can simultaneously measure the leakage inductance and DC resistance of one side of the transformer. [0003] However, there are large errors in the parameter identification results of the above methods. The main reason is: in the process of paramete...

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Problems solved by technology

The main reason is: in the process of parameter identification, the excitation current is ignored, which is inconsistent with the actual situation, resulting in a large difference between the identification value and the actual value; the method of artificially setting the resistance, when the given value is different from the actual resistance or the resistance changes In the case of , it will bring a large identification error to other parameters; for the method of determining parameters through two identification processes, each parameter is not obtained in the same state, and the state of the transformer corresponding to the two identifications may be different, which will also lead to Large parameter identification error

Moreover, after the current method obtains the voltage loop equation, the induced potential is eliminated, so the identification model does not include the excitation branch, and the parameters of the branch cannot be identified

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