All three principle uninterruptible power supply (UPS) systems have their role in protecting today’s dispersed IT infrastructure, particularly on the edge of the network. Almost every technology has its strengths and it may be important to configure cost-effective power safety, particularly in complex systems. Choosing the best UPS for your individual application involves an analysis of a variety of criteria. The workload volume, placement and criticality of the machinery to be secured are important, as are budgetary factors, when selecting a UPS for power backup.
The three most significant forms of UPS machine implementations are online double conversion, line-interactive and offline (also known as battery backup and standby). These UPS systems are characterized by the way power passes through the unit.
Online Double Conversion
After generation, the AC power is safe and clean. However, during transmission and delivery, voltages, spikes and complete failures can disrupt computer operations, bring huge damage and losses to equipment. When it comes to defending vital IT loads, it is only online double conversion technology that completely defends against all these power issues, offering the highest degree of network protection.
An online UPS system is generally referred to as a double conversion since the incoming power is transferred to direct current (DC) and then converted back to AC. This AC-DC/DC-AC configuration provides an improved degree of load insulation from anomalies in the main supply.
The online UPS receives the incoming AC power supply and transforms it to DC by means of a rectifier to support the battery and the attached load through the inverter such that no power conversion switches are needed. If the major AC input breaks, the rectifier will drop out of the circuit and the batteries will maintain the electricity flowing to the unit attached to the UPS. When the AC input control is regained, the rectifier restarts carrying much of the load and continues charging the batteries.
Since electricity is constantly flowing through the online UPS, output is the ideal sine wave. This method of UPS prevents critical load from nearly any power disruption, including slight harmonics and waveform distortions.
This indicates that the efficiency of power from UPS online is way greater than other technology. Offline and line-interactive systems minimize the effect of bursts, pulses and spikes whether by clipping peaks and valleys, improving capacity, or transitioning to battery backup. Even so, most power variations are left behind in the normal track of the electrical sine wave. Online UPS transforms the sine wave, not only the conditioning of raw utility supply.
The online UPS provides constant, high-quality AC power to non-breaking equipment as it is transmitted to a battery, shielding equipment from nearly all power disruptions due to blackouts, brownouts, sags, spikes or noise interruption. A real online, double conversion UPS offers 100% power conditioning, zero transition time to the battery, no difference in output voltage and improved transient reduction than line-interactive devices.
Online double conversion is the most successful UPS mode of service used to secure huge data centers by often producing the maximum amount of load capacity. Online systems also have frequency control, which is important for use with backup generator systems to protect against variations common to generator startups.
The major benefit of Line-interactive UPS is that it provides battery backup and power conditioning equally. It is proved to be very effective for the areas where outages are very uncommon, but power variations are very usual. Line-interactive UPS devices support a wide variety of input voltage changes before the battery backup is switched.
Line-interactive UPS is far better than offline UPS because it offer more control over power fluctuations when it comes to battery backup. The crucial benefit of the line-interactive UPS is the order to further assist circuitry and the selection of input voltage that UPS embraces. The broader the distance, the more complete security you would have.
Line-interactive UPS technology delivers power conditioning with a 4-6 millisecond power loss when switching to the back-up battery which defends against the most frequent power issues encountered in the network. Here, the UPS also tracks the voltage level and adjusts under and over voltages. This technology offers a reasonable option between sufficient security and modest running costs.
For line-interactive UPS, the inverter will be part of the production and will always be on. The inverter will work in reverse to charge the battery when the AC input is regular, and move to battery power when the input drops, which allows filtering and voltage control. Line interactive UPS systems focus on the battery to maintain power such that this model appears to drain the battery more often than the online UPS systems that provide power by a dual conversion mechanism.
When the AC input system crashes, the shift switch of the device opens and the power flows from the battery to the UPS output. With the inverter still on and attached to the output, the line-interactive UPS allows extra filtering and eliminates switching transients as opposed to the standby UPS. Line-interactive UPS devices are usually used for rackmount applications below 5000VA.
Standby UPS, also known as Offline or battery backup, is a cost-effective option. Better offline UPS devices turn to the battery easily enough to avoid power fluctuations and run out of short power outages. The offline UPS defends against most spikes, but does not retain perfect control during small spikes and surges.
The secret to Standby UPS reliability is the range of power the device accepts before returning to battery backup. The broader the set, the less drain on the battery and the more backup time available while the power is turned off. More the time the UPS turns to battery backup, the smaller the battery life.
Standby UPS technology can shield you from most power surges by imposing limits on excess voltage and letting you manage more than 90% of all outages. The Standby UPS device transfers the AC power directly through the unit, past the transfer switch, to the output point where the secured load is attached.
If an input power loss occurs, the built-in battery and the inverter that transforms the DC power of the battery to AC are turned on and attached to the output. There is normally a 6-8 millisecond power loss as it is moved to the battery back-up.
This system is ideally suited for systems below 1500VA, such as small offices, personal home computers and other less important applications. Standby UPS is a great choice for those demanding lower power and cost. Standby UPS technology offers power backup protection for desktop computers, game consoles, workstations, cellular networks and other electronics. During power outage, adequate runtime is given to save the work in the process and to complete an orderly shutdown of the machinery.
How To Choose The Best UPS?
The right UPS choices and the capability of the UPS structure needed for your specific case can be quickly exposed if you answer these three main questions:
- What is my estimated kVA load size?
- What electrical issues, if any, will my load bring to the UPS?
- What are my goals for load protection?
UPS power, and your selection of UPS, will rely very much on the answers you offer to these questions. Another significant factor when selecting the power protection approach is how to balance budgetary and space requirements against the criticality of the organizational workload and stability for future expansion.