DC heavy-current measuring device and measuring method

Abstract

The invention relates to a current measurement technology of electrotechnics and specifically to a DC heavy-current measuring device and measuring method. The device comprises a four-column iron core,an excitation winding, a compensating winding, an excitation signal producing circuit, a driver, a signal conditioning circuit, a power amplifier and a standard resistor. The measuring method comprises the steps of converting electrical current flow to magnetic flux for detection; realizing magnetic circuit splitting through cooperation of a special iron core structure and the bridge-type connected excitation winding; and after performing signal processing on the middle-point voltage difference of the bridge-type connected excitation winding, controlling the current of the compensating winding to enable the magnetic flux to recover balance. Problems such that a zero-magnetic-flux current sensor feedback detection circuit is complex, the compensating current has excitation signal ripple waves, and the transient current and harmonic current are difficult to detect.

Description

technical field [0001] The invention belongs to the technical field of current measurement in electrotechnical technology, and in particular relates to a direct current large current measuring device and a measuring method. Background technique [0002] The application of DC high current in modern industry is quite extensive, among which metallurgy and electrolytic plating are the most common. The continuous development and application of DC transmission technology also put forward requirements for the measurement of DC large current. In addition, some scientific research requires the use of particle accelerators, high-power power electronic equipment, high-power batteries, etc., all of which involve the measurement of DC large currents, and its importance is self-evident. [0003] For energy storage devices such as high-power batteries, the timely and accurate detection of their output current is an indispensable part of testing the electrical performance of the battery. ...

AI Technical Summary

Problems solved by technology

This method does not have the obvious disadvantages of the previous methods, but because the iron core is often in a saturated state, it cannot measure the harmonic components in the DC current, nor can it reflect the transient process of the current; at the same time, the harmonic components in the excitation current will also Affects the size of the compensation current and brings errors to the measurement

In order to measure the transient and harmonic components in DC current, Rogowski coils can be used together, but this will increase the complexity of the measurement, and numerous signal processing links will gradually increase the measurement error

[0010] It can be seen that in order to meet the accuracy of measuring DC large current, anti-electromagnetic interference, and anti-seismic performance, the above technologies still cannot meet the measurement requirements.

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