AFDD is mainly constituted by power module, signal conditioningmodule, electric leakage protectionmodule, trip module and communication interface module etc. Power modulea Supply power for the relevant devices in the AFDD. Signal conditioning module The current signals in the main circuit are passed through the signal conditioningmodule by the line currenttransformer, and are amplified, rectified, filtered and then delivered to the MCU to process by the signal conditioningmodule. Electric leakage protection module The current signals are passed to the electric leakage protectionmodule by the electric leakage currenttransformer. The electric leakageprotectionmodule then detects the electric leakage current, and executes trip when the electric leakage current excess the set threshold value, otherwise not. Trip module The trip module consists mainly of coils, iron cores, armatures, permanent magnets,magnet split plates, tension springs and yokes etc. It executes the operation of trip through receiving the trip instruction from the MCU. In the AFDD, the electromagnetic structure part of the trip module adopts a new type of energy saving technology which reduces the losses of the iron cores and short circuit in the electromagnetic system to the lowest and saves energy at the maximum level. By adding the buffer devicewhich can reduce the yield energy impact of the electromagnetic system, the pull-in performance of the switch is enhanced and its working life is increased. The operating unit of the trip module can receive the fault signals detected by the main control chip (MCU). The coil circuit is cut by controlling the contactor, and the electromagnetic unit will break the main circuit. Open the operating button to reset after removing the fault. Communication interface module Current, voltage, electric leakage, current phase, arc signal and other data can be transmitted in real time to the terminal computer through this module to realize remote monitoring. The picture below shows the current data information the MCU sent to the upper computer when series arc happens.
Data processing module Carry out data analysis and characteristic parameters extraction by using the self-developed special AFDD upper computer development platform. Set up the PC simulator, carry out algorithm pre-simulation on the PC side and execute language and microprocessor general use.
Data processing module