Transient state voltage transformer branch overcurrent simulating method

Abstract

The invention discloses a transient state voltage transformer branch overcurrent simulating method. The transient state voltage transformer branch overcurrent simulating method comprises establishinga high-frequency equivalent model corresponding an electromagnetic voltage transformer; taking into consideration the electromagnetic transient state inside the electromagnetic voltage transformer, and on the basis of the high-frequency equivalent model, dispersing the electromagnetic voltage transformer into n subdivided structures to establish a distribution parameter equivalent model; accordingto the distribution parameter equivalent model and the structural parameters of the electromagnetic voltage transformer, establishing a simulative physical model, and approximating the stray capacitance between the winding of the electromagnetic voltage transformer and a shielding layer; on the basis of a power distribution network and through the distribution parameter equivalent model, the excitation characteristics of the electromagnetic voltage transformer and the stray capacitance, establishing a simulative model in electromagnetic transient state analyzing software to simulate the branch overcurrent of the electromagnetic voltage transformer during asynchronous closing and further to determine the branch overcurrent peak of the electromagnetic voltage transformer. The transient state voltage transformer branch overcurrent simulating method can help simulate the branch overcurrent of the electromagnetic voltage transformer in a transient state, thereby being of high significanceto design and operational reliability of the electromagnetic voltage transformer.

Description

technical field [0001] The invention relates to the technical field of voltage transformers, in particular to a method for simulating branch overcurrent of a voltage transformer in a transient state. Background technique [0002] In my country's distribution network, there are often failures of high-voltage electric energy metering devices, especially on the branch of voltage transformers, where abnormal actions of high-voltage fuses occur frequently, which affects the reliability of power supply and endangers the safety of the power grid. [0003] At present, domestic research has been carried out on this fault, but the root cause of the problem has not been found. Some people have proposed that the main cause of branch faults is ferromagnetic resonance, but the voltage transformers with ferromagnetic resonance phenomenon are all in the Y-shaped connection mode. In the V-shaped connection mode, the system does not form a similar resonance circuit. Some branch faults are al...

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Problems solved by technology

[0005] Aiming at the defects of the prior art, the purpose of the present invention is to solve the technical problem that the traditional inductance model cannot simulate the overcurrent defect of the voltage transformer branch under the transient state

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