The Effect of Tuned Compensation Capacitors in the Induction Motors

Abstract

The load switch-on surge current phenomenon is a key problem for remote loads generally connected to weak or stand-alone grids. This has been the main research topic in smart microgrids. A correlation exists between the motor load and the starting current since a motor usually needs a larger starting current to overcome inertia. Both the power needed to start the load and the higher reactive power demand during the starting procedure are at the origin of the increased current. The current decreases to the nominal value for the specific load gradually after the motor starts. This relationship is essential for figuring out the dimensions of electrical components and protecting the grid and motor from harm. Depending on the load, the switch-on surge current is greater than two to ten times the rated full load current. Energy storage systems can make up for the higher power needed to protect the load and the grid connection. It makes more sense to use tuned compensating capacitors to reduce the reactive power required to reduce the inrush current. The primary focus of this work is the selection, calculation, and switching of the capacitor bank for reactive power compensation. Following the previous research, in this paper, the smaller 2HP induction motor load is examined. The capacitances are calculated, turned on to offset the starting transient, and then disengaged once the machine reaches operating speed. This is done by using a point-on switching technique that lowers the switching transient.