DC link voltage control

A method for operating a UPS system, the method comprising:

• receiving, at an input of the UPS system, input power having an input voltage level;
• monitoring the input voltage level;
• converting the input power into DC power having a DC voltage level;
• providing the DC power to a DC bus;
• converting the DC power into output AC power;
• monitoring a level of the output AC power;
• providing the output AC power to an output of the UPS system;
• and
• adjusting the DC voltage level based on the input voltage level and the level of the output AC power,
• wherein monitoring the input voltage level comprises determining whether the input voltage level is less than an input voltage threshold level, and
• wherein adjusting the DC voltage level comprises, in response to determining that the input voltage is greater than the input voltage threshold level, regulating the DC voltage level to a maximum DC voltage level.

An Uninterruptible Power Supply (UPS) system, the UPS system comprising:

• an input configured to receive input power having an input voltage level;
• an output configured to provide output AC power to a load;
• a converter coupled to the input and configured to convert the input power into DC power having a DC voltage level;
• a DC bus coupled to the converter and configured to receive the DC power;
• an inverter coupled to the DC bus and configured to convert the DC power from the DC bus into output AC power and provide the output AC power to the output;
• and
• means for increasing efficiency of the UPS system by decreasing the DC voltage level in response to a determination that the input voltage level is less than an input voltage threshold and that a level of the output AC power is less than an output power threshold level.