The technical difficulties of a data center are not only its construction and design (like redundancy, distribution basics and cooling), also management of the electricity load is one of the technical challenges of a data center.
Load balancing can have a positive impact on the sustainability of the colocation provider if performed well and can have a negative impact on the client uptime if it is not done properly. Let’s discuss the need for power load balancing on a power feed and the impact it can have.
Generating the power
To understand the reason why load balancing is important, we must understand the power itself. For delivering a high amount of power, most data centers use 3 phase power supplies. In generic, single phase power is commonly used to power a normal home. By default, most electrical grids worldwide deliver 3 phase power on the high-voltage grid. This power consists of waves (Alternate Current / AC), generated by power generators. These generator provision power by the creation of three waves, 3 phase power.
When a magnet field passes the windings, a current exists. Due to the distance between the windings the currents are perfectly divided over the time of one full current, three waves are created with a steady average when accumulating the waves.
Keeping this concept in mind, the power produced is equal on all phases (same frequency, same spikes of the current) due to rotation of the of the electrical field (with approximately 50 Hz in Europe). That is the power created by the generator.
Draw the power
For the generator, it is easy to create power that is equal to all 3 phases. However, when you draw 50% of your power from phase one, 20% from phase two and 30% from phase three, you are out of balance. With a perfectly balanced current on all phases, all phases together will result in zero (due to the waves). In an unbalanced system, there will be a difference in currents and the current together will not add up to zero, therefore they will produce a neutral current. The neutral carries the unbalanced amount of current. Now the unbalanced is created by consuming the power. However, it is possible the power will get unbalanced by creation (e.g. by a difference in windings or defect in windings), by default the main grid will deliver balanced 3 phase power.
Effects of load balancing
When the system is extremely unbalanced, power drops can occur, since one phase wants to draw more power than the other phase. Unbalanced systems can result in overheated phases or overheated neutral wires. Of course, these are the examples that have a very high impact when having an unbalanced system. Another important effect of an unbalanced system is the effectiveness of the power usage, the more neutral current is produced, the more current is not used. When you pay attention being a sustainable company, you must make sure your load is balanced as much as you can, so you limit the neutral power as much as possible and have the most efficient system.
In a data center, having a perfect load distributed over 3 phases is nearly impossible, since power is allocated to different clients. Continuous monitoring and excel in predictive usage will definitely help you in load balancing. Today’s challenges in power management are increasing, flexible contracts will make it possible for clients to change easily in power usage. Continuous monitoring and power management are part of daily operations, due to technical reasons (risk of power drops) and for certifications, law and legislation (optimize efficiency, lower power losses).
Datacenter.com uses continuous monitoring and power management is embedded within our processes.