023 -- Specifying Variable Speed Solutions for Data Center Reliable, Efficient and Cost-Effective Cooling

In 2020, data centers accounted for over 1% of the global energy use, and their energy demand keeps growing year after year. One of the most energy consuming processes in data centers is IT equipment cooling. Variable speed solutions for cooling applications allow substantial improvements to the data center energy performance. They precisely control motors, so those only use the energy required to produce the air or liquid flow for cooling needed at each specific moment. In some cases, the savings can be as high as 60%. The downside of variable speed motor control can be disturbances in the power network known as harmonics. Excessive harmonics negatively affect the reliability of the data center power network and its components, and increase electrical current losses, making power transmission less efficient. The paper introduces active front end variable speed technology for data center cooling. It ensures harmonics mitigation to an absolute minimum over the load profile. Besides improved power network reliability and efficiency, active front end drives allow to save on the project costs. The investigation discusses how with active front end drives, there is no need to oversize power network equipment, which is a common measure to overcome negative harmonic effects. In conclusion, the present paper shows a state-of-the-art variable speed cooling control technology to make data centers more sustainable in terms of energy efficiency and effective material usage.