Lecture 8b: Voltage Regulation - Line Regulator - Power Distribution Systems Spring 2021 - Lubkeman

[@bdcfu]

Can you explain why this needs to be in the neutral position before opening and closing into the circuit? Is it more dangerous if it is in a lower percentage raise or lower position?

[@dr.davidlubkeman284]

The figure you are referring to does not show the tap. But basically when we have a nonzero tap position, we are inserting a portion of Winding 2 in series into our circuit. We can manipulate the Winding 2 connections to get either a voltage raise or drop. If we want to take the voltage regulator out for maintenance and not interrupt the circuit, then we need to close the bypass switch, which will short Winding 2 out. If you have a nonzero tap position, you will have voltage across this winding. So shorting out Winding 2 would result in a substantial fault current. This is why the regulator needs to be in a neutral tap=0 position before shorting out Winding 2.