The transformer which has two kinds of windings be it be single phase transformer or three phase transformer. Every transformer do have input winding, which is called primary winding, and the output winding which is called secondary winding. Input voltage is fed to primary winding and the output of the transformer is connected to the load. The transformers generally used to isolate the input and the output supply. There is only magnetic coupling between primary winding and secondary winding. This transformer is called isolation transformers. These transformers are available in single phase and three phase. In single phase there will be three connections i.e input line, input neutral and input earth. In three phase transformer there will be five wires connected to input of the transformer. Three connections are live connections, forth connection is neutral, and the fifth connection is earth or ground connection.

The purposes of isolation transformer are to isolate input power connections with output power connections of the transformer. Whatever the power quality problems exists on input side of transformer are magnetically transferred to output side of the transformer. It is observed that the leakage current between input and output can be reduced to the great extent by incorporating multiple shieldings at primary and at secondary windings and at the transformer core. Most of the leakage currents can be reduced by incorporating multi stage and multiple shielding, these shielding are incorporated as per the design technique, while constructing the design of the transformer. There are many power quality problems exists on incoming power lines due to which there are lot of failures and premature failures and malfunctioning of the equipments are happening, and this equipments failures are causing a considerable waste of production, down time and money. Many such failures are occurring in electronic products because of not incorporating multi shield transformers which are fitted in the equipments. Most of the transformers used in electronic equipments do not exhibit low leakage and low capacitance. Since the electronic equipments are not fitted with multi shielded transformers the equipments are causing heavy losses to the user, and not incorporating multi shield transformer is one of the major cause of failure of equipment. The non shield transformer will be having high leakage current and high coupling capacitance due to which many equipments are overheating and causing power losses and sometimes fire hazards. Most of the solid state devices semi conductor products and micro controller based products do require quality power to operate smoothly. Many electrical and electronic products are being made “Smart” by using various micro controllers. The clean power is a life blood for trouble free functioning. Generally there are many power quality issues being encountered continuously there are:-

  1. Voltage fluctuations, Power failures, black out, brown out, under voltage, over voltage, sags, dips, surges, swells, impulses, spikes, notches, transients, EMI effects, RFI effects, TVI effects, EMP effects, harmonics effects, differential mode, events, common mode events etc are some of the reasons which is causing heavy stress on all semi conductor equipments.
  2. Apart from voltage fluctuations which are visible there are many invisible power quality problems which is present on power lines. They are sags, are cycle to cycle decrease in power line voltages on any of the phase power lines in the three phase power system.
  • There are voltages dips are very short time occurrences. Some dips are visible some are not visible which can be solved by using the best quality isolation multi shield transformers.
  • Surges are cycle to cycle increase in power line RMS voltage on any of the three phase lines on very short time.
  • Spikes are over voltage an impulse which is ranging from 1000 volts to 10000 volts for very short time super imposition on AC power sine waves.
  • Notches are very short time impulse voltages which are similar to spikes but it is reverse polarity to the instantaneous value of the AC sine wave.
  • Notches are typically too fast to observe. These typically last long as spikes but can be upon several milli seconds in the duration. Spikes and notches are usually appearing on power lines as a pairs and oscillate on lines. For every notch there will be immediate following spikes due to line inductance and capacitance.
  • Transients are very short term event which occurs on power lines, all power line disturbances are transient by definition.
  • EMI broad spectrum electromagnetic noise interference either conducted on AC Power lines directly or radiated to the power lines than conducted to the susceptible equipment. RFI is electromagnetic noise interference in the radio spectrum.
  • TVI is electromagnetic interference in the television spectrum.
  • EMP is a very large and very fast rising electromagnetic pulse caused by catastrophic events.such as lightening strikes and nuclear detonation.
  • Harmonics are sinusoidal currents and voltages with frequencies that are integral multiples of the fundamental power line frequency the Harmonics distort the normal the normal sine wave. There are normal and differential mode seven harmonics which occur across the normal current carrying of the power lines hot wires to neutral wires. Also called as transverse is metallic mode. Common mode events occur from current carry wires and hot and neutral wires. Relative to the safety ground wire.

To provide multi level protection to all costly equipments we have designed a power protection equipment with ultra high isolation transformer with RFI/ EMI filters, surge suppressors, gas discharge tubes and MOV’s as per the site conditions.

Most of electrical related problems can be encountered with the multiple shielding transformers with box type shielding. Each transformer is fitted with appropriate capacity line filters RFI/EMI filters surge protection equipments there by most of line bound power quality issues can be tackled with this multi shield transformers.

Our technology designed innovative shielding technology transformers are manufactured the following manufacturing method.

  1. The transformer is designed at 150% of its rated load. The core is designed with low losses transformer core. The primary winding has been splitted in to two coils for each phase.
  2. There is a gap has been incorporated in primary windings. The primary winding is provided with three shieldings.
  3. The secondary winding has been spilt in to two parts for each phase there is a gap provided between two parts of secondary winding and total secondary winding has been provided with three shields.
  4. One common shielding is provided for entire transformer covering core of the transformer. Thus transformer is having seven shielding. By incorporating with the multiple shielding the coupling capacitance of the transformer is greatly reduced and magnetic leakage is greatly reduced through core and coils. This design and construction of the transformer which provides very high protection against many types of power quality electrical problems.
  5. WE claim patenting about the design of transformer, the construction of transformer, the shielding construction of the transformer.


Coupling capacitance occurs in transformers due to the physical proximity of and electro static coupling between the primary to the core, primary and to the secondary windings, from the secondary windings to the core and between turn to turn in all coils. The capacitance is distributed between the different layers within the windings between primary and secondary windings.

The coupling capacitance or capacitor in the transformer only allows AC signals between the capacitors and blocks the AC signals.

Spikes, surges, noises, harmonics notches, transients, RFI/EMI noises are in the nature of high frequency compare to fundamental frequency.

For good power quality these spikes, surges, noises, harmonics, notches, transients, RFI/EMI to be blocked at input side of transformer which is possible only when the transformer coupling capacitance is extremely low.  Hence the new method of reducing coupling capacitance has been introduced and implemented.

Leakage current and its effects on the performance of capacitance of the transformer. The leakage current flows from coupling capacitance. If coupling capacitance is high there will be more current flows due to which power quality is detoriated. Once the coupling capacitance is less the performance of power quality maintenance increases due to multi shield transformer. Hence multi shield transformer technology is developed to reduce the coupling capacitance and to reduce leakage current. The transformers which are used for medical purpose and power quality improvisation purpose the transformers must exhibit very low leakage current and very low coupling capacitance. Due to introduction of multi shield low capacitance low leakage transformers will increase power quality and saves substantial power and reduce failures of electronic circuits and gadgets and associated machineries.