Research On Measurement Accuracy And Calibration Scheme Of Automatic Verification System For Electricity Metering Equipment

With the intensive management policy implementation of the State Grid Corporation, verification work of metering equipment gradually center to the provincial metering center and verification task is heavier, which makes the construction of the automatic verification system attract much attention. As the important power metering equipment and main verification objects of automatic verification system, measurement accuracy of electricity meter and electric energy data acquire terminal is very important. Therefore, the problem on basic error measurement accuracy of automatic verification cannot be ignored. And study on measurement accuracy and calibration scheme of automatic verification system has important theoretical and engineering significance.This paper introduces automatic verification system for electrical measuring equipment, which classifies identified metering equipment according to the dimensions, builds basic verification unit, designs carrying tray with two meter positions, carry tray with six meter positions, and transfer robot. Then identifies category of metering equipment by using RFID in order to enter different verification process, breaks through bottleneck that dimension of metering equipment and verification process are different. Finally realizes compatible verification of seven kinds of metering equipment, single phase electricity meter, triphase direct access electricity meter, triphase transformer connected electricity meter, collector ?, concentrator ?, concentrator ? and data acquire terminal of special transformer ? included.This paper analyzes the verification data of triphase direct access electricity meter, finds that basic error is serious over the maximum permissible error, and detects the gross error by using Grubbs criterion. The result shows that the basic error which is serious over the maximum permissible error can be removed as gross error. As the traditional basic error calculation scheme cannot avoid the influence of gross error, put forward the new basic error calculation scheme based on Grubbs criterion.This paper designs contrastive experiment between automatic verification and manual verification on single phase electricity meter, three phase four wires direct access electricity meter and three phase four wires transformer connected electricity meter. And the phenomenon that difference between automatic verification and manual verification results partially negative is found. Takes the three phase four wires direct access electricity meter verification data as analysis sample, analyzes the reason of difference partially negative phenomenon from the point of verification wiring principle, and designs experiment to observe the effects of contact resistance on basic error measurements. Through the theoretical and experimental analysis, concludes that oversized contact resistance of automatic crimping device and external connection wire of automatic verification stand leads to automatic verification basic error present negative. And the greater the contact resistance is, the more serious partially negative phenomenon is. Then put forward the calibration measurement to reduce contact resistance.