Establishment method of current transformer engineering model based on transient high current test technology

Abstract

The invention discloses a current transformer engineering model building method based on a transient large current testing technology. The method comprises the following steps: step (1), firstly determining a regional power grid environment of a kind of current transformers under investigation, including an operation mode, and calculating the limit residual magnetism level and the limit transient current level of the current transformers under investigation on various installation locations; step (2), preparing test objects of large current steady state and transient state tests, and building an experimental loop; step (3), performing steady state and transient state large current test; step (4), processing waveforms of the large current steady state and transient state tests; step (5), fitting a hysteresis normalized curve; and step (6), optimizing five key parameters of a J-A model through the fitted hysteresis normalized curve, and acquiring a practical J-A model, that is an engineering model of a current transformer to be established. The method provided by the invention can establish the engineering model of the current transformer which can accurately reflect the transient and large current spread characteristics.

Description

[0001] 【Technical field】 [0002] The invention relates to the technical field of current transformers, in particular to a method for establishing a transient engineering model of a current transformer. [0003] 【Background technique】 [0004] The current transformer is an important component that transmits current signals in the power system, and its reliable operation is crucial to the safety and stability of the power system. [0005] The saturation of the iron core of the current transformer has a great influence on the relay protection. A large short-circuit current will saturate the excitation current, and the secondary current cannot satisfy the linear relationship with the primary current. The current injected into the relay protection device will have waveform distortion, and the resulting error can affect the correct operation of the relay protection. At present, the short-circuit capacity in the high-voltage transmission network is increasing continuously, and the i...

AI Technical Summary

Problems solved by technology

At the same time, the field test workload of this method is relatively large, which is not conducive to the analysis of characteristics of large-scale current transformers.

In addition, this method cannot analyze the transient transmission characteristics of current transformers

[0011] To sum up, there is still a lack of current transformer engineering models that can accurately reflect the characteristics of transient state and large current propagation.

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