Multi-functional Low-voltage Electrical Research And Development Of Comprehensive Test Instrument

Low voltage electrical integrated tester is the instrument of testing safety features in theac1000v and dc1500v low voltage power distribution system of electrical. The potentialsafety hazard of the object being measured be evaluated by using the method of preventive test,so that provides the basis about the object being measured whether the system under test tocomply with relevant electrical safety standards.This topic is based on the domestic marketdemand, with reference to domestic and foreign related legal standards, the development ofhigh-end digital multi-function integrated low voltage electrical tester.Paper elaborates the basic principle、design thought and realization method of Lowvoltage electrical integrated tester. in order to improve the operation speed of tester, outputresolution, stability and accuracy, The design mainly using the new32-bit DSP powerfuldigital computing power. The comprehensive tester contains insulation resistance testingfunction, Loop resistance testing function, grounding resistance testing function and residualcurrent protection device (RCD) testing function and other electrical safety parameters testingfunction.Low voltage electrical comprehensive test instrument consists of measuring system andcontrol system. Measurement system including program-controlled power supply, signalacquisition, conditioning and A/D conversion unit. The core components of the control systembased on DSP. Programmable control power of Control system provides the correspondingincentive to test loop according to the different test function,Voltage signal and current signalthrough the signal acquisition unit into the filter circuit, this signal through synchronous A/Dconversion, finally into the DSP for digital filter and data processing, test results areobtained.In grounding resistance test, in order to avoid the noise and the effects of powerfrequency interference, adopts multifrequency excitation test method and the correctionmethod is based on the twin peaks of tertiary narrow-band pass digital filter, maximum limit tofilter noise signal, and improve the accuracy of measurement.At the end of the test, not only output the current test data, the comparison test results with users to set safety standards at thesame time, to see if it meet the requirements of safety standards, make the tester is morehumanized.Experiments show that the research of low voltage electrical integrated tester, not onlymeets the requirement of IEC61557standard, but also solved the problem of the onlinemeasuring loop resistance, the maneuverability of the instrument is also improved. To narrowthe gap between such instrument technology at home and abroad is of great significance, alsohas a certain social and commercial value.