Research On Theory And Error Of Analog Digital And Mixed Sampling Power Measurement

The power and energy measurement technology is an important area in the electrical measurement, electrical instruments and parameters. Sampling measurement technology is vital in the area. Supported by Heilongjiang Province Natural Science Foundation projects "Research on The Errors Mechanism of Time Division A.C. Power Measurement"(No.E9719), "Research on Theory of Analog Digital Mixed Sampling Power Energy Measurement "(No.E01-15) and Foundation for University Key Teacher by the Ministry of Education "The Research on The Low Audio Frequency A.C. Power Measurement Smart Instrument"(No.1087), in this dissertation it is made that a systematic and deep study on power measurement model errors and instrument errors about analog sampling, digital sampling and mixed sampling measurement, and fully experiments about mixed sampling measurement.The error and model of triangle modulated TDM were investigated systematically. The circuit model, modulated signal model and error simulation model of triangle modulated TDM were established, then by mean of computer simulation, different input signal parameter and multiplier parameter influences on the TDM errors were determined by nature and quantification. Finally the error curves were given. The error and model of current balance passive and active TDM were investigated systematically. The circuit models, modulated signal models and error simulation models of the two TDM were established, then by use of computer simulation, the power measurement model errors and instrument errors of the two TDM were fully analyzed by nature and quantification.The model error and instrument error of digital sampling measurement algorithms were investigated comprehensively. The quantizing error, linear error and differential linear error of an A/D converter were deduced, after that the error model of synchronous sampling, asynchronous sampling and quasi-synchronous sampling algorithms used in power measurement were build in condition that A/D was not perfect. At last by computer simulation the errors of sampling power measurementwere given in form of error curves.The two mixed sampling algorithms was proposed for power measurement. By establishing the mixed synchronous and asynchronous sampling arithmetic, the power measurement error expressions were deduced. By computer simulation, the instrument errors of the two sampling arithmetic were analyzed completely, which were influenced by the A/D and D/A quantizing, linear and differential linear error.A mixed sampling A.C. power converter was designed. The errors of the power converter were tested under the different conditions. The results show that the mixed sampling A.C. power measurement algorithm is correct, small harmonic influence and accurate, which is two grades more accurate than digital sampling power measurement algorithms.