Power Quality Characteristics and Electromagnetic Compatibility of Modern Data Centres

Data centers have evolved to become large power consumers. Their supporting infrastructure includes large HVAC systems, and is in addition to massive computer and lighting loads. Nowadays, some of these centers have been built specifically to mine electronic currency (bitcoins). Their sheer sizes exceed those of typical large commercial customers by a vast amount. With such massive sizes, their impact on power quality has become an important concern and needs to be addressed by careful design. There is a need for research into application of innovative design and technology for conditioning power supply in a system supplying such data centers. This paper presents measurements collected at the Point of Common Coupling (PCC) between the electric utility and two large (20MW and 32MW) data centers. Their impact on harmonic emissions, interharmonic injection, voltage flicker and imbalance are analyzed. It is found that individual device standard compliance does not translate into aggregate load standard compliance, and utilities need to be cognizant of these challenges and work with the customer to strategize effective harmonic mitigation.