Study On The Measuring Errors Of Microprocessor-Base Electrical Quantity Transducer

The measuring precision and response time of electrical parameters is two important characteristic indexes of the electrical quantity transducer. It is meaningful in theory to analyze its measuring errors of electrical parameters and study on the solutions to reduce the measuring errors. The author analyzed in depth the measuring algorithm and synchronous sampling and digital filtering of the electrical parameters in this paper.For the measuring algorithm of the electrical parameters, it was emphasized to discuss the measuring computation of reactive power in three-phase circuits, and the author theoretically deducted its measuring errors in both nonsinusoidal waveform circuits and three-phase unbalanced load systems in this paper.The measuring errors of electrical parameters under the asynchronous sampling is main parts of the measuring errors in electrical quantity transducers, so it is essential to take effective measures to reduce its measuring errors, for this reason, it was emphasized to interpret the basic principle of the measuring algorithm under quasi-synchronous sampling and its digital processing ways. After making simulation on the algorithm, it proved that it could be effective to improve the measuring precision of the electrical quantity transducer.To reduce the influence of various kinds of interference on the measuring results of electrical parameters, it is essential to make filtering for the measuring data of electrical parameters using statistics knowledge. The author interpreted the determinant rule of bad measuring data while power system is in stable state, and implemented the smoothing transition of the measuring results of electrical parameters through curve fitting based on least square while the load in power system is in fluctuation in this paper.