Research On Traceable Measurement Method Of Phase Angle Errors Of Wideband AC Voltage Dividers

With the development of smart grid,new energy,energy-saving and emission-reduction,higher requirements are put forward for ac power standard.The original national audio power standard cannot meet the demand,and the national wideband power standard needs to be established.One of the difficult issues for establishing national wideband power standard is how to reslize the traceable measurement of phase angle errors of voltage dividers.At present,the step-up method is mainly used to measure the phase angle errors of voltage dividers with dual-channel sampling in the world.But the tracing origin of the method is to measure the phase angle errors between output and input signals of the low-ratio voltage dividers directly with a sampling method.The change of the phase angle errors of the voltage dividers at different voltages and the linearity error of the digitizer are ignored.For the voltage dividers used for high voltage measurement,the phase angle error measurement with this method requires multi-step transmission which results in the accumulation of uncertainty.In addition,the method based on the Zero Power Factor Reference(ZPFR)and Thermal Power Comparator(TPC)from National Measurement Institute,Australia(NMIA)can also calibrate the phase angle errors of voltage dividers.However,the requirements for the signal source are high in this method.The measurement system is complicated and there are many uncertainty components.In addition,how to evaluate the voltage dependence in phase angle errors of the voltage dividers is also a difficult issue in the measurement of phase angle errors.In order to solve the problems above,based on the analysis of the phase error sources of voltage dividers and the influence of internal distribution parameters on phase angle errors,a new design of MN resistive voltage divider(RVD)with serial-parallel connection is proposed in this paper.A new method of traceable measurement in phase angle errors of this voltage divider is proposed for the first time to realize the traceablity of the phase angle errors.The phase angle errors of the MN resistive voltage dividers are measured precisely with this method at frequencies up to 100 k Hz.In addition,a calibration method of phase angle errors of inductive voltage dividers(IVD)with cascade structure has also been proposed.The phase angle errors of the inductive voltage dividers with different ratios are measured using the self-calibrated binary inductive voltage divider as the reference standard.The calibration results of phase angle errors of the RVD and IVD have also been compared in this paper to verify the reliability of the two different phase angle error calibration methods.For the voltage dependence in phase angle errors of voltage dividers,as the RVD can be self-calibrated at different voltages directly,the changes of phase angle errors of RVDs can be evaluated at different voltages.The voltage dependence is also evaluated by comparing the RVDs with IVDs at different voltages.The innovative achievements of this paper are as following: 1.A new design of MN resistive voltage divider with serial-parallel connection is proposed.The influence from time constant difference and lead residual inductance of resistive elements is eliminated.The residual inductance and mutual inductance influence in the loop are reduced by optimizing structure and using higher resistors.The phase angle errors from capacitive leakage are also reduced with the reasonable design of voltage divider shell size.2.A new traceable measurement method of phase angle erros of voltage dividers is proposed for the first time in the world.By quantitatively analyzing the relationship between the phase angle errors and the parasitic parameters of the MN resistive voltage dividers,the calibration of phase angle errors of voltage dividers which is difficult to accomplish is transformed into the measurement of the phase angle difference.The traceability of the phase angle errors of MN resistive voltage dividers is realized and the uncertainties are evaluated.3.The problem of voltage dependence evaluation of the MN resistive voltage divider is solved.As the phase angle errors of the voltage dividers can be calibrated at different voltages directly,as well as compared with the inductive voltage dividers at different voltages,the voltage dependence in phase angle errors of the MN resistive voltage dividers is evaluated.4.The calibration method of phase angle errors of the cascaded inductive voltage dividers is proposed.The phase angle errors of the cascaded inductive voltage dividers are calibrated at frequencies from 25 k Hz to 100 k Hz using the self-calibrated binary inductive voltage divider as the reference standard.The calibration results of RVD and IVD are compared and the inconsistency is only 11 ?rad at 100 k Hz,far more less than the uncertainties of the phase angle errors of the two voltage dividers.The two different calibration methods and results are verified to be reliable.To realize the traceable measurement of phase angle errors of voltage dividers,two different kinds of voltage dividers are designed and two independent self-calibration methods are proposed in this paper.A comparision measurement has also been done to verify the calibration methods and results of phase angle errors.The comparision results show that the two self-calibration methods are reliable.Based on the self-calibration method,the MN resistive voltage dividers can be used as the reference standard to calibrate the phase angle errors of the ac voltage dividers and pave the way for the establishment of national wideband power standard.