All You Need to Know About an Uninterruptible Power Supply

An uninterruptible power source is an electronic device providing emergency power to a load when the primary power or input power source is unable to do so. The uninterruptible power source (UPS) is different to an emergency or auxiliary power system, or even a standby generator, in that it provides almost immediate protection from all input power interruptions. This is done by supplying energy stored in flywheels, super-capacitors and batteries. The on-battery running time of the UPS is a relatively short one lasting only a few minutes; however, it is sufficient to begin a standby power source or allow the protected equipment to be shut down properly. This is why it is considered a form of continuous power.

The uninterruptible power supply is most commonly utilised as protection for hardware, such as data centres, computers, telecommunication equipment and other types of electrical resources where an unexpected power disruption can result in fatalities, injuries or serious disruption with data loss. The UPS units range in size from large units powering full buildings and data centres to smaller units developed to protect single computers without any video monitors. The key role of an uninterruptible power supply is to offer short-term power when all input power sources fail to work.

What Types of UPS Are There?

The three categories utilised to define modern UPS systems include on-line, line-interactive and standby. The on-line UPS utilises a double conversion process to accept the AC input and rectify it to DC for passing through a rechargeable battery; then the energy is inverted back to the 120 volt AC to power the protected equipment. The line-interactive system maintains an inverter in line by redirecting the battery’s DC current from the typical charging mode; thereby, supplying current when primary power is lost. The standby or off-line system involves a load being powered directly by the input power; the backup circuitry is only utilised if the input power fails. The majority of UPS below 1kVa utilise the line-interactive or standby technologies because they are less costly. The has a wide selection of UPS batteries for all requirements.

Larger power unites tend to utilise the dynamic uninterruptible power supplies, also known as DUPS. This involves the use of a synchronous alternator/motor connected to the mains using a choke. Energy is stored in the flywheel, and when the main power does not work, a current regulation keeps the energy on the load for all the time that the energy on the flywheel is available. DUPS are typically integrated or combined with diesel generators when turned on after a delay or when forming a diesel rotary uninterruptible power source.

In recent years, the fuel cell uninterruptible power supply has been developed utilising hydrogen and a fuel cell as the power source. This is beneficial as it can provide long-time energy generation in small spaces.

What Applications Are There?

1. N+1

In larger business environments, it is essential that the uninterruptible power supply is reliable; therefore, a single UPS can be a point of failure if it disrupts various other systems. To ensure increased reliability, numerous smaller UPS units with batteries are integrated to provide redundant power protection equal to a large UPS unit. N+1 means that the loan can be supplied by the N modules and the installation contains N+1 units. Based on this, any failure of a single unit will not affect the overall system operation in any way.

2. Multiple Redundancy

The majority of computer services provide an option of redundant power supplies; therefore, in the event of a single failing power supply, other power supplies are able to power the overall load. This is a crucial element as each power supply needs to be able to power the full server on its own.

Redundant protection can be enhanced via connection of power supplies to their own UPS units. It offers double protection from a UPS and power supply failure; thereby, ensuring that operation will continue.

3. Outdoor Usage

If a UPS is placed outdoors, it needs to have certain features to guarantee it will tolerate certain weather without effects on the performance. Factors such as humidity, temperature, snow and rain, among others, must be taken into account by the manufacturer when developing an outdoor uninterruptible power supply.

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