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The operation of transformers can be significantly affected by a change in frequency, but in what ways? Let’s talk about the potential effects of frequency on transformers when they’re not right for your needs and what to do if you’re using the wrong one. 

Potential Effects of High and Low Frequencies on Transformers

Some real issues can arise when an application’s transformer frequency change is too high or too low. 

With higher frequencies:

  • Energy loss worsens.
  • There is a reduction in the cross-sectional area available for electric charge flow.
  • Power is lost due to more resistive dissipation.
  • Magnetic core losses can get exaggerated.
  • The hysteresis effect becomes more severe.
  • Eddy current losses happen more often.
  • Capacitance becomes a concern.
  • The resonant frequency resonates well beyond the frequency of the designed AC power.
  • There can be severe overheating of the transformer.

Why do these problems happen when there is excessive frequency? Because in power systems, nonsinusoidal waveforms will always be higher than the transformer’s design frequency since frequencies are whole-number multiples of the fundamental frequency.

With lower frequencies:

  • Noise and vibration can be a nuisance.
  • The flux requires greater peak levels to produce the same opposing voltage, taking longer to complete and maintain even if the source voltage doesn’t change.
  • DC current is present across the primary winding, causing an additional magnetic flux in the core.
  • There isn’t a safe margin between normal flux peaks and core saturation limits to account for occasional abnormal conditions.
  • Overheating can damage the winding insulation.

If you see any of these problems, they may be signs you’re using the wrong transformer. In an ideal, well-designed transformer, frequency changes are minimized, which decreases risk and cost.

Types of Transformers

Now that you know how a change in frequency can affect the operation of a transformer, it’s time to learn a bit about transformer types. 

There is a wide variety of transformer types manufactured for different applications. Here are some of them, along with their common uses:

  • Communication
    • Telecommunication according to industry standards and customer requirements 
  • Digital Audio:
    • Audio transmission
    • Calibration of current flow
    • DC resistance
    • Sound balance
    • Total harmonic distortion
  • Flyback
    • Power and electrical supply conversion
    • DC to DC power conversion
    • AC-DC power supplies
    • Converters and inverters
    • Computers, PoE motors, generators, and electrical pumps
  • Gate Drive:
    • Insulated-gate bipolar transistors 
  • Isolation:

Isolating electrical devices from the supply line in medical environments 

  • Power:
    • AC and DC motor drives
    • Unregulated power supply
    • Switch-mode power supply
    • Traction motor control
    • Induction heating
    • Inverters

What to Do If You Don’t Have the Right Transformer

Suppose you’re experiencing transformer frequency change or find that the transformer you have is not meant for the application for which you’re using it. In that case, it’s pertinent that you immediately switch it out for the correct one that can handle and maintain proper frequency. 

Contact Schott Magnetics to learn more about preventing frequency change with the right transformer. We can get you exactly what you need, and we also specialize in contract manufacturing per your custom specifications.

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