Data Centers or Data Processing Centers are installations which contain complex and state-of-the-art IT equipment, from computers to storage and network systems. Each electric failure is likely to cause a catastrophe, thus jeopardizing the huge quantity of information they manage. Therefore, the electrical supply of these installations must be continuous and without interruptions.
In terms of system availability, Uptime Institute created the TIER classification system in order to evaluate the infrastructure of data centers. The classification starts with DPC Tier 1, used for small businesses and goes up to Tier 4, used by large corporations.
|1||Without power redundancy.||99,671%|
|2||Partial redundancy in power and cooling.||99,749%|
|3||Outage tolerance N+1. Minimum 72 hours protection before voltage drop.||99,982%|
|4||Totally redundant infrastructure 2N+1. At least 96 hours protection facing voltage drop.||99,995%|
In order for the generator to be considered an alternative power source and to comply with the requirements of Tiers 3 and 4, it’s necessary that it supply continuous power if ever the main power source fails.
For the dimensioning there are 2 standards:
COP power according to ISO8528-1:
It allows the generator to work at 100% of its nominal load for an unlimited period. Dimensioning the generators based on this rating involves selecting bigger engines and making them work outside their maximum efficiency point.
DCC (Data Center Continuous Power):
This rating completes the one defined by ISO8528-1 and allows the generator to work at 100% of its nominal load supplying DPCs. This rating is based upon statistics of diesel engine startups and failures, which help reduce the dimensions of the generators with regard to the COP rating.
The loads applying to DPCs can be divided into:
- Anti-fire system, direct starting engines.
- Continuous supply systems and IT loads.
- Cooling systems.
Normally, when generator sets for DPC are dimensioned, one has to take into account the fact that the amount of nonlinear load, as well as the loads’ power factor (which is usually around 0.9), will be very significant.
Due to these requirements, one must take special care in selecting the engine and alternator in order to achieve an optimal performance without excessively oversizing.
The generator sets we design for DPCs are based on the following criteria:
- All engines have preheating systems to allow the genset to startup in less than 10 seconds.
- The alternators meant for DPCs are supplied with PMG in order to avoid the harmonics induced by non-linear loads.
- The entire control system is powered by engine starting batteries in order to ensure maximum availability.
- A mains-powered battery charger is supplied in order to maintain battery charge.
- Possibility to programme weekly startups for the generator sets to ensure their functioning whenever necessary.
- Startup via external command or due to mains failure
In addition, the generators
can be supplied with certain optional features:
- Synchronization between generators.
- Synchronization with mains.
- Redundancy between units.
- Consumption peak reducing functions.
- Installation in container for outdoor use.
- Monitoring via webserver, modbus TCP/IP or SNMP.
- IT grounding systems for high availability between units.
- UPS and battery systems, as well as transfer systems in one sole power plant.
- Redundancy between two power plants (redundancy between gensets and UPSs).
- Rotabloc technology (dynamic UPS) for the protection of critical loads.
- Custom Scada design for those systems with various generator sets.
Genesal Energy has a multi-discipline technical team with experience in generator projects for different areas (military, information technology, combined cycles and biomass, hospitals, etc…) capable of devising tailor-made solutions, such as:
- Implementation of a tailor-made control system to power 2 DPCs from 2 different networks, backed up by 2 gensets which can power both DPCs individually or jointly by means of a transfer system, maintaining the separation of the DPCs’ supply.
- Synchronization between gensets and upon return of any of the mains networks.
- Redundancy between gensets. Possibility of enabling redundancy between mains networks.
- Redundant electric or electric-air starting systems.