Study on Thermal Overheating Faults of Electrical Equipment Connector Based on Thermal Balance Theory

Taking the bus bar joint as an example, this paper analyzes the sources and influencing factors of the temperature rise of the electrical equipment joints. The main factors of heat generation are heat generated by current through contact resistance and sunshine heating. The heat dissipation channels include radiation heat dissipation, convection heat dissipation, and conduction heat dissipation. This paper establishes a balance equation between heat production and heat dissipation. A thermal experiment is designed, and the relation equation between bus plate joint heating and operation environment is deduced based on the experimental results. It is proposed that when the operating conditions and the environment are different, the key point for determining the detailed quantitative relationship between the temperature of the electrical equipment joints and each influencing factor is to determine the $\alpha$ coefficient and $\varepsilon$ coefficient of the operating environment. Based on these values, the contact resistance of the joint can be calculated and used to evaluate the status of the electrical equipment joints.