Research On Verification System Of High-voltage Electric Energy Measuring Equipment For Primary And Secondary Integration Of Distribution Power Networks

After the primary and secondary integration of the distribution network,the State Grid Corporation regards high-voltage electrical energy measurement equipment as an important means of meticulous scheduling.Its accuracy not only affects the economic efficiency and decision-making of the electricity company,but also affects the fairness and justice of user transactions.At present,the error verification and calibration of measurement equipment mainly indirectly evaluates the overall error of high-voltage electrical energy measurement equipment through the theoretical calculation of the comprehensive error in the low-voltage state.The implementation method in this low-voltage state does not conform to the actual working conditions and cannot accurately evaluate the overall energy measurement performance of the high-voltage energy measurement equipment.In recent years,although the overall error verification technology of high-voltage electrical energy measurement equipment has made certain progress,it still has the problem of leakage current generated by the standard current transformer during the high-voltage state,which affects the accuracy of the current transformer and makes the verification Lose credibility with calibration.This thesis compares and analyzes the traditional high-voltage electrical energy measurement equipment error verification methods,proposes an equipotential verification scheme to eliminate leakage current and a new verification system design plan,and develops a high-voltage electrical energy measurement equipment error verification prototype.The specific work is as follows:A three-phase programmable power source based on DSP has been designed in this paper.In order to improve the output accuracy,the DDS technology and 16-bit high-speed and high-accuracy DAC are adopted to realize high-precision high-order harmonics with extremely low waveform distortion.In order to realize the synchronous tracking of the external synchronous trigger pulse by the DAC,the phase-lock function is realized through the built-in DDS frequency trimming mechanism of the system.In order to output high-voltage AC and DC,the voltage and power are amplified by driving the MOSFET,and the current is amplified by direct resistance sampling feedback.A high-voltage equipotential electric energy standard system has been made.By adopting a double secondary winding bipolar voltage transformer that adds a secondary winding with the primary side as the reference potential,a standard voltage transformer that can provide a high voltage potential reference is realized.By adopting a dual-core,wide-range zero-flux proportional converter with excitation current extraction compensation technology,a standard current transformer with multi-ratio function is realized.By adopting dual iron cores and exciting current extraction technology,a wide-range zero-magnetic-flux proportional converter is developed to realize a standard current transformer with multi-ratio function.Real-time standard electric energy calculation is achieved by a high-voltage electric energy acquisition module based on the BF609 core board and a high-precision AD7608 synchronous sampling analog-to-digital converter.The LoRa wireless communication method is used to send the real-time power to the integrated control unit and compare the electric energy of the tested high-voltage power measuring equipment to calculate the overall error value.On the industrial control computer with Windows operating system,the integrated control unit is designed with human-computer interaction interface through Qt.The prototype of the verification system developed is used to test and verify the high-voltage electric energy meter.The results show that the equipotential verification method has solved the leakage current affection problem,and overall error verification has done.