INDEPENDENT VERIFICATION OF THERMOELECTRIC CОMPARING VOLTAGE CONVERTERS 

Aleksey I. Nefed'ev, Doctor of technical sciences, associate professor, professor of sub-department of electrical engineering, Volgograd State Technical University (28 Lenin avenue, Volgograd, Russia), E-mail: nefediev@rambler.ru
Dmitriy I. Nefed'ev, Doctor of technical sciences, associate professor, professor of sub-department of information and measuring equipment and metrology, Penza State University (40 Krasnaya street, Penza, Russia), E-mail: ndi200106@yandex.ru 

531.714.75 

10.21685/2307-5538-2021-1-7 

Background. For metrological research, an urgent problem is a decentralized verification system based on the use of self-verified autonomous measuring instruments. Thus, an urgent task is the development of autonomously verified thermoelectric comparative voltage converters (TECVC).
Problem and solution. Increasing the accuracy of voltage measurement using thermoelectric comparative voltage converters restrains the frequency error of the additional resistors. This is especially evident at high voltages. To solve this problem, thermoelectric comparative voltage converters for 500V and 1000V were developed, containing additional resistors with three screens, the diameter of which was determined by calculation.
Results. Additional resistors with three screens have been developed, the method for regulating the currents at the input and output of additional resistors by changing the resistance of the screen resistors has been improved, a method has been developed for the experimental determination of the comparison error of converters for 500 and 1000V, which has significantly reduced the frequency error.
Conclusions. Thus, the device for checking TECVC provides an increase in the accuracy of determining and compensating the frequency error of the additional resistor in a wide frequency range, which leads to an increase in the accuracy of voltage measurement using TECVC in a wide range of measured values and frequencies. 

series resistor, thermoelectric voltage converter, frequency error, independent verification