Method for measuring and calculating contact resistance and load capacity of switch cabinet in live operation in real time

The invention provides a real-time measuring and calculating method for contact resistance and load capacity of a switch cabinet in live-line operation, and the method comprises the steps: building a 3D model of the switch cabinet, and carrying out the heat source and temperature distribution analysis; based on a heat source and temperature distribution analysis result, constructing a qualitative thermal circuit model aiming at solving the steady-state temperature of the switch cabinet contact; based on the qualitative thermal circuit model, obtaining qualitative expressions with undetermined coefficients of contact temperature rise, contact resistance and load current of the switch cabinet; performing transformation based on the qualitative expression to obtain a function expression of a relation among the contact resistance of the switch cabinet contact, the actual load capacity of the switch cabinet, the currently measured steady-state temperature rise and the load current; establishing a switch cabinet te