Research and Application of Key Thermal Analysis Technologies for Wide-Range Current Sensors in PV Strings

The increasing power of inverters for photovoltaic (PV) strings imposes higher requirements for the thermal design of maximum power point tracking (MPPT) current sensors. This paper focuses on the heating issue associated with copper busbars in MPPT current sensors. Firstly, a precise mathematical model was established based on heat transfer theory and considering the electro-thermal coupling characteristics of copper busbars, creating a method for theoretically calculating temperature rise in these busbars. Next, ANSYS finite element analysis software was used to develop a thermal simulation model to numerically simulate temperature rise in them. Subsequently, an experimental platform was built to measure their actual temperature rise. The experimental data showed good agreement with the numerical simulation and theoretical calculation results through a comparison, with a maximum error of less than 3%, verifying the accuracy and reliability of the proposal thermal model and theoretical calculation method. The study findings provide an important reference for the thermal design of wide-range current sensors.