Smart voltage reduction

Abstract

Over the years, voltage reduction has been implemented using different techniques. In the early days, a summing transformer was added to the sense voltage input on the LTC/regulator control. There are many disadvantages to this system-among them being the need for follow-up commands to exit voltage reduction and hardware changes if voltage reduction needed to be implemented. This paper explains a smart voltage reduction algorithm that will allow for the maximum percentage of reduction without the need of reducing the bandwidth or requiring multiple levels to be entered. The simple steps of disabling band edges and applying reactive compensation in the correct direction can both increase the amount of reduction and also allow the system to return to normal quicker when exiting reduction. With the newer digital controls, voltage reduction can now be performed without the need for external transformers, and three levels of voltage reduction-typically between 1–10%-can be implemented via software. This allows the user the ability to remotely change the percentage of reduction without changing any hardware, a major benefit. A second major benefit is in response time. A third benefit is that there is verification that the control is in reduction mode. This paper provides an overview of this Smart Voltage Reduction system and these benefits.