Simulating The Effects of a Transfer Switch

The purpose of this application note is to demonstrate how to simulate the phase shift that may be encountered on an AC line when power is applied from a second, “synchronized” source of AC Power. While the power lines are generally locked in frequency, phase shifting can often occur. Shown below are methods used to create a phase shift using Pacific's UPC-Series Programmable Controller. The goal is to create a sub-cycle offset that can be programmed to occur at any phase angle on the fundamental waveform, and last for a specified number of degrees.