Calibration device for large current test equipment

Abstract

The invention discloses a calibration device for high current test equipment, which comprises a singlechip microcomputer system, a solid-state voltage regulator, a solid-state relay, a rectifier bridge, a square wave generator, a current transformer, a display screen, a control panel, a power switch, a control transformer, a rectifying and voltage stabilizing circuit, a logic level transfer circuit and a calibration module, wherein the calibration module comprises a relay switching circuit and a calibration coil, the calibration coil is provided with three taps, and the input end of the square wave generator is provided with a rectifier diode and a switch contact. The whole calibration device is small in size and light in weight; the required power supply capacity is small, and the calibration device can be used by being powered by a general 220V power supply, so that the calibration device can be used in general office places; the calibration device is convenient to trace the source, and the source tracing cost is low; the calibration cost is low; and mobile calibration is realized. The whole device is similar to a common computer case in size and completely integrated together, does not have an installation and debugging process, and is plug-and-play.

Description

technical field [0001] The invention belongs to the technical field of high-current testing equipment, and in particular relates to a calibration device for high-current testing equipment. Background technique [0002] The output current of resistance welding equipment (also known as resistance welding machine) or similar equipment (such as magnetizer) is very large, generally at the level of kiloamperes (kA) and 10,000 amperes (10kA). To calibrate and / or test its current, people Developed and manufactured a high-current test device (commonly known as high-current tester) capable of testing 2kA to 200kA. This high-current tester is based on the Rogowski coil as the current sensor, and the Rogowski coil is used to obtain the variation of the measured current (that is, the differential signal ), the internal circuit of the instrument obtains the value of the tested current through integration and digital processing. Based on this principle, the high current tester can test ...

AI Technical Summary

Problems solved by technology

[0003] 1) The source used for calibration is very heavy, generally 100kg~250kg (reason: the current that needs to be calibrated is generally 3.5kA~50kA, and a large current needs to be obtained, which must have a large input capacity. Some similar current boosters (such as welding transformers) ) The active parts need liquid cooling, so the overall mass and volume will be relatively large);

[0004] 2) Calibration needs to provide a large power supply capacity, and the capacity will be in the tens to hundreds of kVA level. It can only be calibrated in a dedicated site or laboratory, and cannot be calibrated in an ordinary site with only 220V socket power supply (reason: It is necessary to obtain a large current, and the input capacity must be large. According to regulations, the current of ordinary sockets does not exceed 16A);

[0005] 3) It is difficult to transfer the value (called "traceability" in metrology), and the cost of traceability is high, and many can only be traced to 10kA, and very few can be traced to 50kA (reason: the commonly used current range is generally below 5kA, most The unit of measurement will not establish a current benchmark of tens of thousands of amperes);

[0006] 4) High calibration cost (reason: currently, the equipment capable of calibrating 10,000 ampere level is bulky, heavy, occupies a large area, high equipment cost, large power configuration, and high depreciation costs);

[0007] 5) Basically mobile calibration cannot be realized, and the equipment cannot be easily transported to units with calibration requirements for calibration (reason: the calibration system is divided into several major components, which need to be disassembled, transported, installed and debugged)

Images