The Design Of Data Synchronous Acquisition System For AC&DC Multi Function Detector

With the development of technology, the detection of electric power is enteringa new phase. More electric parameters need to be detected, including harmonicanalysis, DC component, unbalance of three-phase circuit, in addition to RMS,frequency and phase of voltage and current. The detection usually required a lot ofinstruments, such as frequency meter and power meter, which made the workinefficient and the workload heavy. To improve the efficiency of the detection, ahigh precision AC&DC multi-functional meter, integrating the functions above inone machine on the precondition of high precision, is introduced here.The instrument is divided into two parts in the virtual instrument way:high-speed Data Acquisition, PC application software. Communication between PCand DSP data acquisition is provided by A Serial-Port Communication technology.The upper computer realizes the waveforms of data real-time display, data synthesisand software system accuracy adjustment. The central processor of this equipment isTMS320F2812produced by TI. High precision resistor and current transformer isadopted in order to ensure test accuracy, and two single channel16-bit A/Dconversion chip ADS8515and LTC2414based on sigma-delta conversiontechnology is employed, combined with analog switch technology to achievemulti-channel data acquisition. Involing AC-electrical, deviation cumulativeincremental synchronization sampling method is used. The instrument is able toaccurately check up parameters of AC/DC current and voltage, realize timemeasurement and waveform data replayed.In this paper, theoretical analysis,the selection of overall program and thedesign of hardware and software are elaborated in details in order to describe theprocess of the instrument design.This paper firstly puts forward the background andthe significance of this research, and also its current status at home and abroad isconclude. Then, the functions it’s expected to achieve and their algorithms areexpanded. Among this process, it mainly introduces the choosing of samplingalgorithm, algorithm for measurement of general parameters, harmonic wave andphase. It also introduces the implementing scheme of wave-recorded. Then, concerned to the functions it needs to possess, we decide the hardware realization ofthe whole system and divide it into six modules. And the special description has beengiven on the circuit structure and DSP software of these modules. Finally, thequestions and solutions during the process of adjusting hardware, software and debugare presented. The experiments show that the design can satisfy the purposes. It hasthe advantages of multi-functions, high-precision(0.05), easy-operation and friendlyinterface.