Experimental and Analytical Study on the Bus Duct System for the Prediction of Temperature Variations Due To the Fluctuation of Load

In this paper, a thermal model is developed for the bus bar system to predict thetemperature variation during the transient time period and to calculate both the steady-state andtransient electrical current carrying capacity (ampacity) of bus bar. The bus bar system installed in thepower house of Kumaraguru College of Technology, Coimbatore has been considered. Temperaturevariation predicted in the modelling is validated by observing the current and steady state temperaturesin different feeders of the bus bar. Magnetic field of the extreme phases R and B induces more currentin the middle phase Y. Hence, the steady state temperature in the phase Y is greater than other twophases. The transient capabilities of the bus bar are illustrated by calculating the variations in the busbar temperature when it is subjected to a step change in current during the peak hours due to increasein hostel utilities and facilities (5.30 pm to 10.30 pm). The physical and geometrical properties of thebus bar and temperature variation in the bus bar are used to estimate the thermal time constants forcommon bus bar cross-sections. An analytical expression for the time constant of the bus bar isderived. KCI Citation Count: 2