Development Of Detection Device For Tester Of Digital Relay Protection

In recent years, since the application of electronic transformers and circuitbreakers and other intelligent equipments，it accelerates the development process ofsmart substation and makes the information acquisition, transmission, processing, andoutput of substation digitized. Relay protection devices have achieved digitizedoptical fiber communication and proposed new requirements for the detection of newrelay protection devices.Development and application of tester of digital relayprotection based on DL/T860standards helps to improve the level of protection, relayprotection and automatic safety devices prevent incorrect operation to protect thesecurity and stability of the operation,so it has important practical meaning. In orderto realize the testing for digital relay protection devices, Tester of digital relayprotection came into being, but there are no devices for detecting tester of digital relayprotection, so the development of detection device for tester of digital relay protectionhas an important significance.This paper has designed and developed a detection device for tester of digitalrelay protection that can not only detect the completion of12-channel small analogsignals, but also complete detection of sample values based on IEC61850-9-1,IEC61850-9-2LE and IEC61850-9-2protocol. This detection device could achieve thedetection of12-channel small signals and waveform display of amplitude, frequency,phase of sample values based on IEC61850protocol data for each channel, so itcompletes the main function of tester of digital relay protection detection.In the smallsignal acquire module,TMS320F2812DSP processor are core processor,high-precision A/D chip ADS8556and non-synchronous sampling methods are usedto achieve acquisition of signal.The datas which have been collected are transmittedto the host computer, then the host computer will processe and operate them. Opticalswitch which achieves the conversion form optical signals to electrical signals areused in the sample value analysis module of IEC61850.Then this paper uses the visualdevelopment tool Delphi to call the function of winpcap to achieve the capture of datain network card. The four-term fifth derivative Nuttall window and interpolationalgorithm which help to amend the calculation result of FFT and achieve a higherprecision are used in the datadispose module.Firstly, this paper makes a brief introduction to research significance and status of device for tester of digital relay,then expounds the IEC61850protocol in detail,and mainly introduces the four-term fifth derivative Nuttall window and interpolationalgorithm. The paper analyses the hardware circuit in detail and makes illustration tothe theory of circuit with schematics. The section of software provides flow diagramof program, and the capture of analytical sample values are described in detail.Finally, shortcomings are found through experiments, then more steps are taken toimprove and perfect the system.