Design And Application Of Digital Insulation Resistance Tester

Insulation resistance testing of electrical equipment safety requirements is animportant indicator in the test, is also the main parameters to effective determineinsulator integrity and the insulator surface is contaminated. Defects can be detectedin time equipment generally damp, local severe damp and penetrating by measuringthe electrical equipment insulation resistance value.Insulation resistance test is strong items seized in the measurement of law inChina electrical equipment safety testing project. Insulation resistance test is the valueof leakage current through the instrument to measure the electrical equipment in thehigh pressure which exists. Usually the instrument to the current value aftercalculation shows that the insulation resistance value(Ω). In this paper, high frequencyand high voltage switching power supply and single-chip microcontroller introducedinto the insulation resistance test system, measurement automation, digital and widerange, meet the needs of electrical equipment for measurement of insulation resistancemeasurement technology.The insulation resistance test is the conventional means of testing and inspectionof electrical equipment insulation performance or failure. Applicable equipment,including motors, transformers, detectors, switching devices, control devices andother electrical devices in the winding, cable insulation materials, Various types ofsensor signal line and shell insulation also determines the detection accuracy of thesystem.First, brief and clear introduction to the current development of the technicalbackground of the insulation resistance tester, as well as domestic and foreign,elaborate the content of this paper. Second, combination of insulation resistancemeasurements require high voltage and weak current, by analyzing the causes of the error in insulation resistance measurement, decision to the MCU as the core of thesystem, using the pressure method of measuring flow measurement solutions. MCUcomplete data acquisition and processing the converted digital signal, and completedthe keyboard input, LCD and other functions. Part of the pressurized flowmeasurement using a combination of single-ended flyback DC/DC converter andmulti-order voltage double rectifier circuit, according to the settings AC and15V DCpower supply voltage through a transformer rectifier output four different stalls ofhigh-voltage source. Paper is detailed analysis of high-voltage power supply designmodule works, it should be noted in the electrical and structural design problems andcorresponding solutions. In the subsequent resistor voltage divider circuit, thestandard voltage divider with the measured insulation resistance in series,High-voltage resistor divider and the measured resistance by the standard partialpressure signal. Signal acquisition module on the partial pressure signal generated bythe standard resistance for signal acquisition and A/D converter, Last measureddigital partial pressure signal sent to the MCU processing, MCU according to thepartial pressure signal calculated the insulation resistance value of the measuredresistance and through the LCD display. In addition, the article also extended massstorage unit through the microcontroller interface, the measured insulation resistancevalue, measurement date, and on-site temperature and humidity parameters to recordin the form of long-term preservation of the memory cell, meet the insulationparameters measurement of large volumes of data requirements, facilitate the databack to check. In the second half of this article, combined with software flow chartbriefly discusses the design ideas of the entire software system and a number ofimportant signal processing module program. The entire software system is written inC, four parts: LCD part, keyboard processing module, analog/digital converter anddata management component. Finally, instance of measurement systems designedmachine test, have satisfactory experimental results, and detailed description thesystems in the detector.