Power Transformers – Know How to Purchase One

Power transformers occupy a major role in electricity distribution networks. With outstanding voltage regulation and power conditioning features, they enable spectacular applications in power generation plants, power distribution centers, and certain industries as well. As our power demands are growing day by day, several power transformer manufacturers in India are engaged in providing suitable efficient power transformers.

But, how to know what power transformer we need? Most of us know that they are step-up and step-down transformers regulating voltage. Still, this is not just enough. One should have an idea of many key elements to purchase the right power transformer for a specific application.

Things to know before purchasing power transformers

Here are certain important things you should keep in mind to choose and buy a power transformer.

  • Standard of the Transformer

The transformer standard is denoted by its efficient function itself. The construction and function of the transformer should be perfect to avoid any kind of loss – no load or load losses. Even when there is no load or equipment, a certain magnetizing current is required to enable the core function. While certain current or energy loss is evident, the function of power transformer gets affected.

Moreover, when the loads are varying, the resistance due to winding can also cause certain transformer losses. Hysteresis and Eddy current losses due to core lamination, dielectric losses during excitation, and so on are such losses that should be avoided. Effective design and manufacturing, therefore, determines the standard of the power transformer.

  • HV and LV Or Primary and Secondary

The primary and secondary voltage levels of the power transformers have to be known when you want to purchase one. They are to be designed as step-up and step-down transformers based on your applications.

You should understand the voltage ratios of H.V side (like 33kV, 66kV, 132kV & 220kV) and L.V side (like 11kV, 33kV and 132kV etc. Remember, based on these ratios also, the price of the power transformers varies.

  • Load MVA

The size, capacity, and nature of the load or equipment to which the transformer should supply sufficient voltage levels are also important. Consider the total MVA of all the loads if you are considering purchasing a power transformer for your industry or power plant.

  • Size or Capacity of Power Transformers

Not only the load requirements but also the features like size or capacity of the power transformers are considerable. Remember that the transformers’ capacity should be of a higher size to assure a buffer and minimize the overload risk. For example, if you want a power transformer with a capacity of 9.5MVA, you should purchase one with 10MVA or other nearby higher standard capacities for a safe side.

  • Installation Location and Environment

Generally, transformers can be installed indoors or outdoors. However, most of the power transformers are installed outdoors because of their relative applications. But, you should keep a view on the installation location and space available.

The environment or surroundings in which you want a power transformer is also significant. Because, the power transformers are used in places where harsh environments like dust, moisture, heat, etc. are evident. So, the design of the power transformers should withstand such atmospheres.

  • Impedance

It is the drop of voltage in the power transformer that is observed on full load due to leakage resistance and winding resistance. It is denoted by percentage. The higher the impedance percentage of the power transformer, the more current faults happen in its function. So, check the impedance levels of the power transformer before you buy one.

  • Current Density

Current density is the current flowing through per unit time in a unit cross-sectional area. Checking the current density is very important – both the primary and secondary windings should have the same current density. Checking the star or delta connections, windings, etc., the current density can be specified as per your requirements.

  • The Winding of the Transformer

The primary and secondary windings of power transformers are the key to increase or decrease the voltage levels.  The windings should be of the best quality more overly copper– if not, they don’t function well. They are built with multi-layers of wire coils that are double-enameled. Specific insulation means like paper are used in the windings. Check the number of coils in the primary and secondary coils required for step-up or step-down of the voltages.

  • Tap Changer Selection

To get the desired voltage regulation, certain taps can be designed in the power transformers to modify the turns of the windings. They enable accurate voltage output even with off-rated voltage supply. Consider the on-load and off-circuit tap changers that can enhance the power transformer voltage control.

  • Efficiency

A power transformer works perfectly if it has 99.9% efficiency. This means, there are no operational losses during their function. Transformer losses like copper losses and iron losses are caused due to some problems in the windings and core assembly respectively. But, such losses should be minimum – only then, the transformer efficiency remains high. If you use high-grade raw materials and world-class standards in manufacturing the power transformer, then the efficiency will be maintained.

  • Reliability

Power transformers should be highly reliable – they should operate effectively even in case of maximum load capacity. If not, their function breaks down showing bad effects. Such transformers can’t work longer and their effective performance decreases. So, your investment in purchasing a power transformer gets wasted. We don’t expect to get an unreliable product, right?

So, ensure that you purchase a reliable power transformer from the best power transformer manufacturers like Servomax Limited. The transformers will be reliable and function efficiently when there are minimum soldering joints – so, there should be continuous windings to assure excellent functioning during maximum load conditions.

  • Tank

Being used in industries, power generation plants, and power distribution stations, the power transformers are exposed to severe physical, thermal, and environmental stresses. But, the components of the transformers should not get affected by them. So, the transformer core, insulating coils, and the whole assembly should be carefully enclosed in a tank that is built strongly. Also, the tank should be resistant to corrosion and also should be preventing any leakages (oil in case of oil-cooled models).

  • Vector Group

The winding configurations and the phase angle difference between the windings are considered to be the vector group. The vector group of the transformers should be suitable with the power network connections – if not; there will be certain disturbances in the currents.

  • Protection Means

The protection means of power transformers are very much important. For instance, if there are frequent sudden voltage fluctuations, then the transformer components and the associated equipment will also get damaged very early. However, this should be prevented to protect the power transformer. So, Bucholz relay, explosion vent, air cell, silica gel, alarm trip contacts, LA’s or circuit breakers have to be used to manage such voltage spikes, fire, moisture, and other malfunctions.

Moreover, the power transformers get heated with huge applications. So, the best cooling or insulation means are necessary to protect their parts. Oil-based or air-forced cooling and high-end insulation class strategies protect the transformers from damages. Make sure you get the protection details from the seller before you purchase one.

  • Power Transformer Manufacturers

Be attentive to choose famous power transformer manufacturers like Servomax Limited. The quality, efficiency, and safety of the power transformers from such companies are excellent as they are made under strict national and international standard regulations. So, select the well-known power transformer manufacturing company to assure the best products.

Now that you have got these considerations, observe each of them carefully; identify your specifications and requirements; and make the right choice to purchase the best power transformers. Servomax Limited is the leading power transformer manufacturer in India that gives you 100% satisfaction.