UNITERRUPTIBLE POWER SUPPLIES

What is an UPS?

The fundamental function of an Uninterruptible Power Supply is to ensure the supply to utilities in any situation and it can be implemented through different architecture technologies and relevant operating procedures, that have peculiar characteristics and that can be more or less optimal according to the type of load to supply.
Elettronica Brianza is the authorized reseller of a wide range of equipment and products in the field of energy conversion systems, in order to meet all the needs of privileged energy supply. The opportunity to deal with many and different technologies, used by the various manufacturers, gives the advantage of offering the most suitable product for the requested application, with the due attention to budget requirements. Elettronica Brianza sells, installs and gives service assistance to all the major brands of UPS and inverters. Recognizing our customers’ needs and facing in a suitable way the technical circumstances and situations allows us to offer the utmost supply: suitable commercial proposals and a single partner for the technical assistance of your set of equipment, even if multibrand.

UPS are the solution for the most common power supply problems such as sudden power failure, voltage peaks or drops, dangerous overvoltage (caused, for example, by thunderbolts), power disturbances, frequency changes, transitory events lasting few seconds, harmonic distortion. There are many technologies and formats available. To guide you in your choice, you can find here below the available UPS grouped by categories and applications.

Line interactive

For LIB regulations (Line Interactive with By-pass): UPS operating interactively with the grid, through an automatic switch; the utility is powered by a stabilized voltage thanks to the connection in parallel of the entry power and the inverter exit. This architecture requires an impedance between the grid entry and the UPS exit.
In this category, unlike the normal Line interactive UPS systems, we propose only UPS equipped with AVR (Automatic Voltage Regulator: output voltage stabilized through Buck-Boost technology), with smart battery control to extend duration over time and with true sine wave inverter. It is well known that in some applications the modified sine wave or square wave can cause utility failures or unacceptable disturbance. UPS Line interactive power normally never exceeds 3KVA.

Online

State-of-the-art continuous UPS, usually called on-line Standalone UPS, supply exit with a perfect sine wave. They guarantee top level performances, mainly addressed to industrial applications, electromedical devices, computer systems, telecommunication systems, computer networks, IT applications and all critical medium and large power systems. There is a wide variety of models with structural flexibility for the various applications they are destined to. Their characteristic is a minimum distortion in input current, DSP digital control, IGBT inverter with PWM modulation at high frequency and high efficiency at three levels. When operating normally, the load is always powered by the inverter, whereas a control system decides if the inverter has to be powered by the battery or by the grid. In case of any event occurred to the power grid, the shape of the output wave remains rigorously sinusoidal. In case of inverter failure, thanks to the integrated static switch, accidental load shutdowns as well are prevented. These systems are called double conversion UPS, one referring to the grid rectifier and the other to the inverter that transforms continuous current into alternating current.

Offline in ultra efficiency

In this type of UPS, the load is powered by the grid through a static switch inside the machine. In case of “anomaly” in the electric grid or input blackout, the UPS supplies power by using the inverter. The inverter acts so promptly (2/4 milliseconds) that the load does not even perceive the changed conditions. To reach various efficiency levels (between 95 and 99,5%) manufacturers apply different methods:

ECO MODE: This is the simplest and most common technique as the load is on bypass grid through static switch, the rectifier and the inverter are always on power with a self-consumption that rarely exceeds 96% efficiency. Some UPS models have a switch time that can reach up to 10 milliseconds that for some utilities is poorly tolerated. Although this is the most known model, according to our on-field experience, it is the less used for energy saving purposes.

Energy Saver System (ESS): Power is supplied through a static bypass switch, that allows the UPS to pass to double-conversion mode in less than two milliseconds in case the fixed input limits are exceeded. Losses are extremely low with this system because the inverter does not have any self-consumption during the standby phase, though ensuring the immediate synchronized power on. The ESS mode allows to filter short-time low energy events.

Variable Module Management System (VMMS): This function allows to optimize the load levels of power modules in single or parellel configuration UPS systems, disabling the UPS supplementary capacity. This not only allows a higher efficiency in case of low load levels, but also an optimized functioning at all absorption levels, thus allowing to optimize the UPS performance according to load variations or to power conditions.

Ultra High Efficiency (UHE): Based on a sophisticated control technique, UHE mode pledges 99,46% efficiency, granting the maximum protection from the loss of power quality. In case of temporary disturbance, blackout or micro-interruptions that are close to the load immunity levels (compliant with EMC international standards), the rectifier and the inverter so far in “deep standby” mode immediately start by taking the load through static switch.

Very High Efficiency (VHE) interactive mode: When this operating mode is active, loads are powered by the grid or by the inverter, that is switched on or off by the control logic. Once the maximum tolerance limits are set by the operator, the UPS will decide the better way to power the utilities, either through the inverter or through the bypass line. In this case efficiency could drop to 97%, due to the overall self-consumption contribution of the inverter and the rectifier.

Modular UPS

The modular UPS with online double or triple conversion technology is an architecture that many manufacturers have been strengthening for years. The systems capacities vary from few KVA to more than 10 MW. The system is composed of hot-swappable power modules included in a parallelable context making the expansion capacity potentially unlimited. The system is reliable and gives high performance for critical loads in a reduced volume thanks to its high power density. The modular design allows an easy scalability without disconnecting the UPS from the load. These systems are designed to ensure redundancy and their typical application is in data centers, where power density and maximum structural flexibility are fundamental requirements. Maintenance operations are simple thanks to modules that can be pulled out and replaced (hot Swap), in few minutes (thus minimizing MTTR), while the unit is still operating and protects the load.