Research On Test And Calibration Method Of Wide-frequency Measurement Device

High proportion of renewable energy and high proportion of power electronic equipment are becoming an important trend and key feature of power system development,which brings great changes to the dynamic behavior of power system.The power signals exhibit the characteristics of wide frequency band,rapid change and high noise.Wide-frequency measurement devices can measure accurately and track quickly wide-frequency signals,which provides conditions for power grid monitoring and visualization.In order to ensure the reliability of the measurement results of the wide-frequency measurement devices,it is necessary to test and calibrate the devices.In this paper,the study of test and calibration of wide-frequency measurement device is taken,the test scheme and evaluation method of wide-frequency measurement device are proposed;The resampling method of filter design based on window function method is studied;The high-precision wide-frequency measurement method for calibrator is proposed;A test platform for wide-frequency measurement based on calibrator is developed,and testing and calibration of wide-frequency measurement devices of seven manufacturers are carried out.In view of the lack of test scheme and evaluation method for wide-frequency measurement devices,the research object of wide-freuqency measurement is proposed firstly,the static and dynamic characteristics of wide-freuqency signals in actual power system are analyzed,and the mathematical model of typical wide-freuqency signals is abstracted;The test scheme of wide-frequency measurement device is proposed,in which static test scheme includes multi-harmonic/inter-harmonic test and dynamic test scheme includes wide-frequency modulation,wide-frequency frequency ramp,wide-frequency step and wide-frequency amplitude divergence,and the evaluation indexes of each test are specified.As calibrator needs to have the function of resampling to meet the demand of flexible sampling rate adjustment,the resampling model based on Farrow structure is analyzed,the interpolation filter characteristics of the resampling model are revealed,and the filter design criteria are proposed;The fractional delay filter design model based on window function method is established,and a simple Farrow structure subfilter coefficients design method is proposed;Simulation results show that the proposed method can effectively prevent frequency aliasing and mirroring during sampling rate conversion without affecting the low frequency signal.Aiming at the problem that the existing wide-frequency measurement methods cannot meet the test and calibration accuracy requirements,the phasor measurement method based on complex sequence bandpass filter and spectral line fitting are studied;A static and dynamic identification method of wide-frequency signal is established;And the characteristics of complex sequence bandpass filter designed by Kaiser window are analyzed;Then a high-precision broadband measurement method suitable for calibrator is proposed.The test results show that the proposed method can perform high-precision measurement of complex static and dynamic signals,and the measurement results can be more than two orders of magnitude higher than the proposed evaluation indexed.Finally,a architecture of wide-frequency measurement device test platform based on calibrator is proposed,a high-precision calibrator is developed,and the calibrator is tested;A test system software is developed,and the wide-frequency measurement device test platform is built;The platform has been applied in China Electric Power Research Institute,and wide-frequency measurement devices have been tested and calibrated,which verifies the practicability and effectiveness of the test platform.