A new technological approach can cut the energy costs of  uninterruptible power supplies (UPS) by as much as 75% in high-end applications and can reduce the required input power for a given system load by 10%, writes Chloride technical support manager Rob Tanzer

Data centres have always used the same basic technology to guarantee the quality and continuity of their power supplies. An online double conversion UPS, feeding DC from constantly recharged batteries to an inverter and thence to the load, is the standard and very effective way of protecting data centres from substandard or interrupted power.

It is also an energy intensive solution costing data centres between five and ten per cent of their total critical power throughput. It is, on its own, no longer the only, or most efficient way for UPS systems providing secure power to loads such as Tier IV data centres and the large IT systems typically used by financial institutions and government.

Savings and  change: switching from traditional data centre UPS
New technology introduced by Chloride’s new Trinergy UPS is the first of its kind to offer an alternative to full time double conversion for the most sensitive data centre loads, where online double conversion UPS has hitherto been considered to be the only way to provide secure power.

It is the first UPS able to switch automatically to two, more efficient, functioning modes as an alternative to double conversion technology, whilst maintaining the performance and power protection of a Class 1 (IEC 62040-3) UPS for the load and perfect input power conditioning (THDi 0.99). As a result Trinergy offers up to 99% efficiency with a typical overall efficiency, in the context of UK power conditions, of 97.9%. Over the lifetime of a typical data centre UPS such efficiency gains – of perhaps 5% to 10% per year - translate easily into seven figure savings even for a medium-sized data centre.

A new technology to meet standards for the most secure power
The new Trinergy technology constantly monitors input power supply and the electrical environment. Whilst it has recourse to an optimised version of traditional double conversion technology to cope with the most extreme electrical events, it automatically and seamlessly selects the most appropriate and efficient of three different functioning modes, two of which are much less energy intensive then the traditional double conversion process. Trinergy, at all times, retains the performance and power protection of the Class 1 UPS demanded by the Tier IV data centre.

Maximum Power Control mode (IEC 62040-3 VFI) is Trinergy’s fall back double conversion mode that provides the highest level of power conditioning. Only used when power disturbances make it absolutely necessary, it protects the load from all types of electrical network disturbances. In this mode, Trinergy’s efficiency at full load is better than 95%.

Trinergy’s novel High Efficiency & Power Conditioning mode (IEC 62040-3 VI) enables the UPS system to condition the energy supply, when minor disturbances to input power supplies are detected, which prevents switching to Maximum Power Control configuration. When a non linear load is connected to the UPS and harmonics are present, Trinergy compensates by using its inverter as an active filter, giving all the necessary reactive power and consuming only the energy needed to compensate for line disturbances. This achieves the highest efficiency possible based on the quality of disturbances, resulting in an efficiency variation of between 96% and 98%. Within most parts of UK where the quality and voltage accuracy of the AC supply is generally good, the Trinergy will return efficiency figures of around 98%.

The Maximum Energy Saving mode (IEC 62040-3 VFD) is used when Trinergy detects that there is no need for conditioning of either the AC incoming supply or the system load current and it allows energy flow to pass through the bypass line and power interface. In this case efficiency reaches 99%.

A new paradigm for power protection in data centres
After over thirty years in double conversion mode, data centres now have the opportunity to reduce energy costs significantly, with a new technological model for power protection. Processes from banking transactions to cloud services, and the foundations of the Internet itself, will be made significantly cheaper. Older, more expensive models for providing secure power are becoming increasingly unaffordable and well on the way to obsolescence, as seven figure savings are made possible by potential cuts in energy bills of 10 per cent and sometimes more are made achievable with the adoption of the third generation of UPS technology.  

Hidden Savings
Modern IT loads and rising energy costs demand that a new UPS must be able to accept any lagging or leading load power factor without sacrificing power capability. This capability is standard to all Chloride UPS systems.  In addition, as a result of its IGBT rectifier and the inherent power conditioning capabilities, the Trinergy always draws power from the incoming AC supply at near unity power factor and with low THDi - in all modes of operation.

This can be especially useful in situations where a diesel generator is required, since it almost eliminates the need for oversizing, which can offer significant capital cost savings. This results in further energy savings and potential reductions in cost of switchgear because of the reduced input current that is required to support the same load power.