Grounding Resistance And Equipotential Bonding Automatic Detection System

Grounding and equipotential bonding are two important protective measures of lightning protection in modern buildings. The performance of the two measures directly influences the running state of power equipments and the power system, even closely relates to personal safety. Grounding resistance and equipotential bonding resistance are indexes to reflect the lightning protection performance. As a consequence, it is important to measure the values of them accurately for ensuring the electrical equipment, power system, and even personal safety.Firstly, this paper discusses the significance and necessity of grounding and equipotential bonding, makes analysis and comparisons of measuring principles and methods, and introduces the problems of traditional measuring methods. According to the principle of clamp meter, grounding resistance and equipotential bonding automatic detection system with Zigbee wireless data transmission is designed based on C8051F020MCU. The system consists of data collection, data communication and the upper management software. Data collection includes main controller C8051F020, signal generating circuit, signal process circuit, A/D sampling circuit and so on. The signal generating circuit generates sine excitation by the direct digital frequency synthesis. The digital signal processing is realized based on Fast Fourier Transform in the MCU. The communication module transmits data through the chip CC2530, and achieves the wireless and networked measuring. Taken Visual Studio2005as the development platform and SQL Server2005as the database, the upper computer software is designed with real time monitoring and management.Finally, the system is tested and analyzed, the feasibility of every module is verified. The online measurement of grounding resistance and equipotential detection is achieved. The automaticity and networking of the system reduce the intensity and improve work efficiency for personnel.