Design Of Calibration Device For Network RCD Detector

The residual current protective device(RCD,residual current protective device)is an electrical protection device applied to prevent electric shock,electrical fire and electrical equipment damage in low voltage power network.The calibration device of RCD detector is designed,which combines the application of measurement control technology,computer technology and network technology to realize automatic and intelligent calibration,and transmits data through the network.It completely solves the drawbacks of the traditional methods,which are complex,low efficiency,and data can not be saved automatically.The device takes split current measurement method due to the characteristics of current measuring range span.The device takes 24 bit ?-? high speed analog-to-digital converter to achieve the sampling of current value due to high precision requirements.The device choose CPLD to precisely control the switch timing,due to the high requirements on switch timing control.Based on the collecting of current value,the switch timing control and the display and storage of data,which are all realized by Cortex-M3 ARM,and also based on the LTE mobile network,measurement data from the device will be reported to the client,with data analyzed and auto-generated electronic certificate.Using the standard current source to test the current accuracy of the device,the measured maximum error is-0.2%,which fully meet the design requirements(the residual current maximum permissible error as ±0.5%).Using digital stopwatch to test the switch timing of the device,the measured maximum error is-0.7%,fully meets the design requirements(maximum permissible error of the breaking time is ±(0.1%×reading +1)ms).Applied to automatic calibration of the RCD tester,the device can upload real-time calibration data,and finally generate the calibration certificate.The RCD tester calibration device can meet the design requirements through experiments.It can quickly promote the automatic operation ability of RCD tester calibration,and it improves the calibration efficiency,and bring considerable economic benefits.