CN105467344A - A metering calibration method for switch transient testing stand asymmetric components - Google Patents

Abstract

The invention relates to a metering calibration method for switch instantaneous testing stand asymmetric components. A switch instantaneous testing stand presets an expected short circuit current. Through a high precision oscilloscope, output current waveforms of an instantaneous trip characteristic testing stand are acquired. A positive and negative peak difference of the first output waveform is measured. The metering calibration method for switch instantaneous testing stand asymmetric components provided by the invention can determine whether the instantaneous stand is in accordance with the national standard through measuring and calculating asymmetric contents of output currents of the instantaneous trip characteristic testing stand by means of a prescribed limit value.

Description

Measurement and Calibration Method of Unsymmetrical Component of Switch Instantaneous Test Bench

technical field

The invention belongs to the field of electrical testing equipment, in particular to a method for measuring and calibrating an asymmetric component of a switch instantaneous test bench.

Background technique

The measurement of asymmetrical components is an important measurement and calibration index of the instantaneous switch action characteristic test bench, which ensures that the characteristic test bench of circuit breakers and other products meets the requirements of national standards during 3C certification and factory inspection. However, the calibration lacks certain norms and operation standardization and unified steps, which has caused great obstacles to the operator in the actual calibration process, not only affecting the work efficiency, but also causing large errors in many test benches, and even causing damage to the test bench. . Therefore, the problem to be solved urgently is to seek a measurement and calibration method for the asymmetric component of the switch instantaneous test bench with better applicability.

Clause GB14048.2-20088.3.3.1.2 clearly stipulates that when conducting the breaking characteristic test under short-circuit conditions, it is required that the test current should have no asymmetrical component. According to the requirements of national standards, it is necessary to measure and evaluate the symmetrical component of the output current of the instantaneous characteristic test bench. The existing measurement and calibration methods for the characteristic test bench are only for the calibration of transformers and display instruments, and cannot evaluate this technical index. In the domestic and foreign specifications, there is no clear measurement method for the asymmetric component of the instantaneous test bench.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the prior art, to provide an asymmetrical component of the switching instantaneous test bench to ensure that the existing characteristic test bench is more in line with the requirements of the national standard, and to ensure that the performance of components such as circuit breakers is more superior. measurement calibration method.

The present invention solves its technical problem and realizes by taking the following technical solutions:

A method for measuring and calibrating the asymmetrical component of a switch instantaneous test bench. The switch instantaneous test bench is given an expected short-circuit current, and the output current waveform of the instantaneous tripping characteristic test bench is collected by a high-precision oscilloscope, and the positive value of the first output waveform is measured. Negative peak difference, the measurement formula is as follows:

$\mathrm{<span\; class="notranslate">\; D.</span>}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; |</span>\frac{<span\; class="notranslate">\; |</span>{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}<span\; class="notranslate">\; +</span>}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; |</span>{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}<span\; class="notranslate">\; -</span>}<span\; class="notranslate">\; |</span>}{<span\; class="notranslate">\; |</span>{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}<span\; class="notranslate">\; +</span>}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; +</span><span\; class="notranslate">\; |</span>{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}<span\; class="notranslate">\; -</span>}<span\; class="notranslate">\; |</span>}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; 100</span>}\mathrm{<span\; class="notranslate">\; \%</span>}$

In the formula: D—the difference between positive and negative peak values in the first period, %; I _p+ —upper peak value, A; I _p -—lower peak value, A.

Advantage and positive effect of the present invention are:

The method for measuring and calibrating the asymmetric component of the instantaneous tripping test bench provided by the invention is to measure and calculate the asymmetric content of the output current of the instantaneous tripping characteristic test bench, and determine whether the instantaneous tripping test bench meets the national standard by specifying the limit value.

Description of drawings

Figure 1 is the output current waveform diagram of the instantaneous trip characteristic test bench.

detailed description

The present invention will be further described in detail below in conjunction with the accompanying drawings and through specific embodiments. The following embodiments are only descriptive, not restrictive, and cannot limit the protection scope of the present invention.

A method for measuring and calibrating the asymmetric component of the switch long-time delay test bench. The asymmetric component appears in the disconnection test under the short-circuit condition, and an expected short-circuit current (0.2s, s refers to is the time "seconds"), collect the output current waveform of the instantaneous tripping characteristic test bench through a high-precision oscilloscope, and measure the difference between the positive and negative peak values of the first output waveform. The measurement formula is as follows:

$\mathrm{<span\; class="notranslate">\; D.</span>}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; |</span>\frac{<span\; class="notranslate">\; |</span>{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}<span\; class="notranslate">\; +</span>}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; |</span>{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}<span\; class="notranslate">\; -</span>}<span\; class="notranslate">\; |</span>}{<span\; class="notranslate">\; |</span>{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}<span\; class="notranslate">\; +</span>}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; +</span><span\; class="notranslate">\; |</span>{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}<span\; class="notranslate">\; -</span>}<span\; class="notranslate">\; |</span>}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; 100</span>}\mathrm{<span\; class="notranslate">\; \%</span>}$

In the formula: D—the difference between positive and negative peak values in the first period, %; I _p+ —upper peak value, A; I _p -—lower peak value, A.

Although the embodiments and drawings of the present invention are disclosed for the purpose of illustration, those skilled in the art can understand that various replacements, changes and modifications are possible without departing from the spirit and scope of the present invention and the appended claims Therefore, the scope of the present invention is not limited to what is disclosed in the embodiments and drawings.

Claims (1)

1. A metering and calibration method of the asymmetrical component of the switch instantaneous test bench is characterized in that: an expected short-circuit current is given by the switch instantaneous test bench, the output current waveform of the instantaneous tripping characteristic test bench is collected by a high-precision oscilloscope, and the first measurement is made. The difference between positive and negative peak values of an output waveform, the measurement formula is as follows: $\mathrm{<span\; class="notranslate">\; D.</span>}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; |</span>\frac{<span\; class="notranslate">\; |</span>{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}<span\; class="notranslate">\; +</span>}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; |</span>{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}<span\; class="notranslate">\; -</span>}<span\; class="notranslate">\; |</span>}{<span\; class="notranslate">\; |</span>{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}<span\; class="notranslate">\; +</span>}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; +</span><span\; class="notranslate">\; |</span>{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}<span\; class="notranslate">\; -</span>}<span\; class="notranslate">\; |</span>}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; 100</span>}\mathrm{<span\; class="notranslate">\; \%</span>}$ In the formula: D—the difference between positive and negative peak values in the first period, %; I _p+ —upper peak value, A; I _p -—lower peak value, A.