| The intelligent current protector is used in electric power system for real-timeprotection in short circuit, overload and grounding fault. The parameter test systemdeveloped by XiaMen LEELEN Electric Control Technology Corp.LTD had theproduct species single, poor continuity test, slow speed of signal data acquisition andlarger error.The performance which is not stable, unable to realize network,intelligent and automation level. As a result, the intelligent over-current protectorparameter testing system is analyzed and developed in this paper.First，this paper analyzed the deficiency existing in current test system and putforward new requirements and general framework. The intelligent controller made theSTC89C51MCU and PCI-7489as the core and based on principles of modularity toswitch protection parameter data channels and controlling amplitude and frequency ofthe voltage signals for testing. In order to meet the precision of data signal, itabandoned the traditional amplification circuit based on voltage transformer to designPA90high fidelity and low ripple signal power amplification circuit. To avoid theeffect of the surrounding environment and improve data acquisition precision ofamplifier circuit, it designed temperature control system. In data channel switch, thispaper proposed to relays as the core and, the relay control system of multi-channelcollection of real-time data processing to realize multiple parameter measurement ofmultiple products.Secondly, this paper designed a PC test system by VisualBasic6.0to realizecentralized control, scheduling and management for intelligent control unit.Intelligent test system of measurement has monitoring, protection, communicationand other functions. In order to reduce the error in the process of real-time acquisition,this paper applied the ARMA model of time series BP neural network to the softwarethrough the research of different amplitude and frequency of the signals by threekinds of methods. The gross error can be eliminated in the acquisition process toforecast accuracy. The software used modular programming method according to fullstudy of measurement and protection and improved the software system flexibilityand portability effectively by hierarchical and multi task. The experimental results showed that the output sine wave test signal waveformwithout distortion, no drift, error ranged in3‰in the intelligent over-currentprotector parameter test system. The output voltage can range in0-300V andfrequency50-60HZ adjustable. The device has been used by XiaMen LEELENElectric Control Technology Corp.LTD in2014and the indicators have reachedpredetermined requirement. |
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