What Distinguishes a Transformer-Based UPS from a Transformerless UPS?

In any industry, choosing the appropriate UPS system is crucial to guaranteeing power availability for key loads. A crucial part of the essential power infrastructure, UPS is used to power everything from industrial automation to medical devices like CT, MRI, cath laboratories, and X-rays. It is also a cornerstone of information technology systems, providing excellent power and backup to both data centres and small offices. Customers must carefully examine the topology that best meets their demands because there are numerous designs for online double-conversion UPS systems. Here are a few of the topologies:

Transformer-based UPS, transformerless UPS, and transformerless UPS with an external input/output transformer are all possible configurations.

The UPS models differ according to brand. Before evaluating the models of some of the top manufacturers on the market, we will first explore the benefits and downsides of UPS systems in the first session.

Transformerless UPS 

Insulated Gate Bipolar Transistors (IGBTs), which can handle high voltages and eliminate the need for a step-up transformer after the inverter are used in transformerless UPS or transformer-free UPS systems. This can control high voltages, obviating the need for bulky, expensive, and noisy transformer components. These systems are versatile, simple to install, and easy to move. Compared to uninterruptible power sources that use a transformer, this improves their energy efficiency.  Their smaller size and lighter weight translate into cheaper initial costs and ongoing running expenses. 

As power electronic components advance and improve, particularly the IGBT, online UPS systems without transformers are starting to replace conventional transformer-based online UPS systems at UPS sizes of 300 KVA and below.

It might not be as straightforward as it seems to choose a transformer-based or transformer-less UPS. Considerations for a UPS include size, effectiveness, and dependability, among other things. Even though these are the most important factors, many other factors must be taken into account before deciding. We will now go over the various things to take into account while choosing a UPS.

• Weight: The transformerless UPS is less expensive to ship because it is lighter and can be positioned on a raised floor.

• Heat Output: The system produces less heat, so there may be less of a requirement for precise cooling of the power equipment.

• Voltage: When the input voltage is above 305 Vac, an input voltage in the wide range of 138–485 Vac (phase voltage 80–280 Vac) can be received without derating.

• Energy-saving: A three-level inverter architecture with an efficiency of up to 96% and a high input power factor of up to 0.99.

• Versatile battery configuration: Depending on the requirements, the number of batteries in each group can range from 30 to 50.

• High load capacity: The output power factor is 1.0, the UPS can power a 100% unbalanced load.

• Excellent load adaptability: The system can link complete inductive or capacitive loads.

The reduced physical footprint of transformerless UPS systems necessitates that the price of real estate is factored into the total cost of the systems. Transformerless UPS systems are especially suitable for budget UPS solutions and IT/ICT infrastructure that makes use of linear load characteristics. They are also perfect for use with linear-load laboratory equipment, CT and MRI scanners, and imaging machines. Transformerless UPS systems are substantially more efficient than traditional UPS systems thanks to the use of IGBT technology, reaching up to 90–96% efficiency, making them a greener option. Moreover, transformer-free UPS systems are a fantastic option for delivering backup power for CCTV or IT demands.

Transformer-based UPS system

Galvanic isolation between the rectifier and UPS output is provided by a built-in transformer in transformer-based UPS systems. This arrangement allows two distinct sources to be connected to the rectifier and bypassed without compromising the current earthing system.

Working in advanced mode

Systems for uninterruptible power supplies (UPS) use a double conversion online design to produce a pure sine wave output with frequency tracking, phase-lock, voltage regulation, and noise suppression. Its design ensures a consistent and uninterrupted power supply, eliminating any influence from power fluctuations and providing the load being supplied with full protection.

Precision equipment's high standard power requirements are met by the output offered by UPS systems, which claim a zero transfer time. The reliability of the power supply is increased by this function, which guarantees a consistent and dependable power supply.

The filter used in UPS systems improves energy efficiency, lowers harmonic power grid pollution, and reduces the cost of UPS's operation. Moreover, this filter raises the input power factor to 0.98, which reduces waste and increases system efficiency.

• Whole DSP control

• Digital control not only offers better performance but also reduces the likelihood of analogue failures and guarantees more stability and dependability.

• A significant output power factor

• The output power factor allows consumers to increase loading capacity while lowering investment expenses by up to 0.9.

• Broad adaptability

• Reduced frequency of battery use and longer battery life are achieved by the AC input voltage range of (380 VA, 400 VA, and 415 VA): +25%.

• All fuel generator types will operate steadily thanks to the wide input frequency range of 45 Hz to 65 Hz.

• High-performance battery improvement

• Use intelligent battery management (ABM) technology, which prolongs battery life and requires less upkeep.

• Modern floating switching and charging techniques maximise battery activation while reducing charging time and boosting battery life.

• The system recognises the discharge current and anticipates the discharge time when the battery discharges, in accordance with battery intelligent management. By doing this, it alerts consumers to take the necessary action.

The start time and length of the battery self-test should be set in accordance with the various periods (monthly or weekly) for the battery self-test in order to discover battery concerns early. Transformer-based UPS systems are advised for financial, transportation, data centre building, and industrial applications, including the steel, oil, and metal industries, when the dependability and stability requirements are higher.

Transformer-based UPS sometimes referred to as ‘semi-industrial UPS’, is mostly used for cath lab machines, MRI machines, X-ray machines, etc. Moreover, it's used in tough environments for very important loads, packing plants, automation plants, factories, and central UPS systems when the load is non-linear. It's also employed in laboratory equipment.