Apparatus and method for on-line resistance measurement

Abstract

The invention discloses a resistance value online measurement device for resistors and a method thereof. The resistance value online measurement device comprises a measurement circuit composed of a power supply and serially connected a variable reference resistor and an inductor, while an object resistor is connected with the inductor in parallel, and the measurement circuit is used to select theresistance value of the reference resistor, respectively measures and outputs the effective voltage value of the power supply, the voltage values at two ends of the reference resistor and the voltagevalues at two ends of the inductor; and a resistance value computing unit for calculating the resistance value of the object resistor according to the resistance value of the reference resistor, the effective voltage value of the power supply, the voltage values at two ends of the reference resistor and the voltage values at two ends of the inductor. The invention changes direct measurement of phase difference into direct measurement, for resolving the technical problem of online accurate measurement on resistance value, and realizing effective, fast and accurate online measurement of resistance value of resistors, which has the advantages of low measurement error and simple application.

Description

technical field [0001] The invention relates to an on-line measurement technology of resistance resistance, in particular to a device and method for quickly and accurately on-line measurement of resistance resistance using a phase method under the condition that resistance and inductance are connected in parallel (RL circuit). Background technique [0002] In the process of online measurement of resistance value by phase method, the accuracy of phase angle (phase difference) is the key point of the whole measurement process. At present, there are two commonly used methods for measuring the phase angle: [0003] One is the phase measurement method using the filling counting method. Generally, the zero-crossing phase detection method is used to obtain the phase value between two signals of the same frequency; the principle of the zero-crossing phase detection method is as follows: two measured signals of the same frequency are shaped into two square wave signals, and the lead...

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Problems solved by technology

[0007] 1. This method cannot judge which signal is leading or lagging between the two signals at all, so it is difficult to accurately measure the phase difference between the two measured signals;

[0008] 2. The use of special instruments and meters has the defects of high price and large measurement error, which is not conducive to popularization and use

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