Voltage measuring circuit, method and equipment

Abstract

The invention relates to a voltage measuring circuit, method and equipment. A to-be-measured conductor is electrically coupled to the voltage measuring circuit by adopting a first coupling device and a second coupling device, a coupling capacitor is formed between the to-be-measured conductor and the coupling devices, and when a voltage measuring device obtains a reference signal source and independently acts on the voltage measuring circuit, the first reference voltage division value at the two ends of the voltage division capacitor bank performs analysis. If the ratio of the first reference partial voltage value to the reference voltage value of the voltage measuring device does not meet the preset ratio range, the voltage measuring range (the reference voltage value) of the voltage measuring device is not matched with the measured voltage value (the first reference partial voltage value) at the moment. At the moment, the voltage measuring device changes the size of the first reference partial voltage value by adjusting the capacitance value of the partial voltage capacitor bank so as to enable the first reference partial voltage value to be matched with the reference voltage value, and therefore the problem that in the voltage measuring process, due to the fact that the measuring range is too large or too small, the measuring result is inaccurate is solved.

Description

technical field [0001] The present application relates to the technical field of power measurement, in particular to a voltage measurement circuit, method and equipment. Background technique [0002] Voltage measurement is widely used in power systems, such as relay protection, electric energy metering, control of intelligent equipment, and online monitoring of overvoltage and other fields. The accuracy, reliability, convenience and speed of voltage measurement are related to the reliable implementation of power metering, relay protection, power system monitoring and diagnosis, power system fault analysis, etc. At present, the most common voltage measuring device used in the power system is the electromagnetic voltage transformer. [0003] With the rapid development of the national economy and technological progress in the power system, power production and capacity transmission have been greatly improved, and the operating voltage level of the power grid is also gradually ...

AI Technical Summary

Problems solved by technology

This will cause the measured voltage value collected by the measuring device to fluctuate greatly, and may exceed the range of the measuring device in a short time

The specific performance is: when the coupling capacitance value between the probe and the line to be tested is large, the measurement voltage collected by the measuring device will increase significantly, and after exceeding the range of the measuring device, it can only be calculated according to the maximum range, resulting in incorrect calculation of the final result; The coupling capacitance value between the probe and the line to be tested is small, resulting in a significant decrease in the measurement voltage collected by the measurement device. At this time, the voltage resolution of the measurement device is relatively large, which forms a contradiction in measurement accuracy with the small measurement voltage collected. , will also lead to incorrect calculation results

Therefore, the traditional non-contact voltage measurement scheme has the problem of low accuracy of measurement results

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