Design of Intelligent Detection System for Loop Resistance Under High Current

This paper designs a smart high-current loop resistance detection system in accordance with the latest testing regulations for GIS equipment loop resistance, DL/T 618-2022. Based on the high precision and low power consumption of 24-bit Σ-Δ analog-to-digital converter chip, the current output module, voltage measurement module, microprocessor unit and user interface hardware module were system constructed. The resistance voltage division scheme was utilized to realize the switch of the test system gear to ensure the 300 A current condition circuit resistance test. And a buzzer alarm circuit was equipped to ensure the application safety. At the same time, the WiFi module was used to transmit and store data in the cloud. The deviation rate between the standard resistance was less than 5%, and the deviation rate between with the loop resistance measurement value of the high-precision benchtop equipment was less than 1% in the actual field test. This indicated the developed system had high application reliability.