Device and method for measuring longitudinal equivalent capacitance of transformer coil

Abstract

The invention provides a transformer coil longitudinal equivalent capacitance measuring device and method.The device comprises an oscilloscope, a pulse signal generator, an adjustable capacitance box and an isolation power source which are installed in a box body, the pulse signal generator is connected with the adjustable capacitance box, and the oscilloscope is connected with the adjustable capacitance box; the isolation power supply supplies power to the oscilloscope and the pulse signal generator. The pulse signal generator outputs a voltage with a certain waveform to the coil to be tested and the adjustable capacitance box, the capacitance of the adjustable capacitance box is adjusted, so that the voltage value of the capacitance of the adjustable capacitance box is equal to the voltage value of the coil to be tested, and the capacitance of the capacitance box is equal to the longitudinal equivalent capacitance of the coil to be tested at the moment. According to the scheme provided by the invention, the longitudinal equivalent capacitance of the transformer coil is measured in a very simple manner, and the problem that the energy equivalent method cannot be used for calculation under steep waves is solved; by connecting the device with the transformer coil, the problem of temporarily establishing a test loop is avoided, and the measurement work flow is simplified.

Description

technical field [0001] The invention belongs to the technical field of transformer testing, and in particular relates to a device and method for measuring the longitudinal equivalent capacitance of a transformer coil. Background technique [0002] The current transformer in operation will encounter lightning overvoltage. Under the action of lightning overvoltage, voltage distribution is carried out in the transformer coil. The most relevant voltage distribution is the capacitance distribution of the transformer coil. The capacitance distribution can be simulated by design. By comparing the measured actual value with the design value, the measured value is used to improve the initial coil voltage distribution under the action of the steep wave impulse voltage. In the existing calculation methods, the energy equivalent method is generally used for calculation, but when the wave front time of the invading lightning wave is short, the magnetizing current cannot be established be...

AI Technical Summary

Problems solved by technology

In the existing calculation methods, the energy equivalent method is generally used for calculation, but when the intruding lightning wave front time is short, the magnetizing current cannot be established within the wave front time, and this method cannot be used for calculation, etc. Therefore, it is necessary to carry out a research on the measurement method of the longitudinal equivalent capacitance of the transformer coil

At present, there is no mature special test device for this kind of measurement research, so it is necessary to design and develop a set of special test device and measurement method

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