Measurement method for periodic signal effective value

Abstract

The invention provides a measurement method for a periodic signal effective value on the basis of establishing a mathematical model among conduction time, signal frequency, bias voltage and an effective value. The method comprises the following steps that: (1) amplifying a periodic signal v(t) to be measured for A times (A is greater than or equal to 1 or A is greater than 0 or less than 1) to obtain a signal x(t), carrying out VDC superposition on the x(t) to obtain x(t)+VDC; (2) obtaining the frequency f of the x(t); (3) generating a central symmetry triangular wave of which the frequency isN*f and the amplitude is VCC; (4) carrying out logic comparison on vc(t) and x(t)+VDC to obtain a digital signal Vpluse; (5) capturing the conduction time Ton<K(DC)> of the Vpluse, storing the conduction time in an array, and on the basis of an effective value calculation formula, calculating the effective value Xrms of the x(t); and (6) calculating the effective value Vrms(=A*Xrms) of the periodic signal v(t) to be measured. Since the a periodic signal v(t) of the effective value is of a general form and can contain a direct current component and a harmonic component, the applicable range ofthe effective value calculated by the method is wider.

Description

technical field [0001] The invention belongs to the field of metering, and in particular relates to a method for measuring the effective value of a periodic signal, which is used for measuring the effective value of any periodic signal. Background technique [0002] The effective value measurement of periodic signals plays an important role in the fields of instrumentation, signal processing and measurement and control, and is an important part of electrical parameter measurement. There are mainly the following schemes for the measurement of the effective value of the periodic signal: (1) The effective value of the periodic signal is obtained by measuring the maximum value (or average value) and the waveform coefficient of the periodic signal. This solution is only applicable to some specific standard AC periodic signals, such as standard sinusoidal signals, symmetrical triangular wave signals, and the like. This is because for a standard sinusoidal AC signal: For a symme...

AI Technical Summary

Problems solved by technology

The corresponding effective value calculation formula is Since the FFT calculation of periodic signals takes up a lot of memory resources, the hardware requirements and software algorithms are very high, and its accuracy is restricted by the truncation frequency n, which will occupy a large amount of CPU system memory and running time, resulting in accuracy and calculation time. Costs have to be compromised

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