Analysis And Study Of Harmonics’ Impact On Electronic Integrator’s Calibration

With the development of electronic technology, electronic integrator are extensively used in measurement field, especially be used to measure the physical parameter which are change with time quickly. In the application of electronic integrator, exact calibration is the prerequisite and foundation of accurate measurement. Volt-second generator is often used to calibrate the electronic integrator, the volt-second signals have same value and different pulse width has different spectral distribution, but besides the principle error, the cut-off frequency and loss angle tangent value of capacitor also has harmful effects on calibration because of sensitivity to a frequency. In order to improve the accurate of calibration, it is absolutely essential to do research into the influence of harmonic, and then chose appropriate parameter for Volt-second generator to calibrate the electronic integrator.This paper first reviews the current integrator, and then analyzes the mathematical model of the integrator, after that makes detailed introduction on harmonic analysis method. On this basis, the paper focuses on the calibration of the integrator engage in intensive study focused on the same volt-second value different pulse width signal integrator calibration error analysis, and completion of validation experiments. The works for the integrator’s calibration factors is as following:First, this paper designs integrator calibration scheme. Second, To reduce the integrator principle error. This paper analyze non-ideal the operational amplifier caused integrator drift and the error caused by the tangent of the integrator capacitor. This paper designs the compensation circuit and test different integrator drift experiment. Third, this paper designs the volt-second signal source. The pulse width of the signal source using MCU precise control achieve lms accuracy reached 2%. Different amplitudes of the signal source using the standard source and the voltage divider network achieve 1mV accuracy reached 5%.The control part of the signal source use low on-resistance analog switch MAX4678. Fourth, this paper analyzes the impact of harmonic upon integrator’s Calibration. The spectrum analysis of the same volt-second value signal was made through LabVIEW. The mathematical model of integrator established by using Simulink, and then the output curve of volt-second periodic signal through integrator was simulated. At the same time, the theoretical analysis integrator in volt-second value the same volt-seconds signal to the integrator calibration signals in the influence of the harmonic wave to integrator. The number of the same volt-seconds under the condition of different integrator output harmonic content contrast. Fifth, this paper analyzes the degree of influence of the capacitor dielectric loss tangent and the integrator time constant calibration of the integrator.Experiments results show that harmonic integrator calibration is the third harmonic content of the signal source and the loss angle of the capacitor capacitance at different harmonic components.