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waqasakbar323
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Why transformer core is modeled as resistance even though it is frequency dependent.With increasing frequency current rises. Doesn't it seem capacitive reactance behaviour? Which decrease with increasing omega?
A power transformer is specified for operation at a fixed frequency.waqasakbar323 said:Why transformer core is modeled as resistance even though it is frequency dependent.
Correct, it make sense. But because in reality harmonics exist and are growing with increasing power electronics. So if someone want to model transformer, specially for harmonic studies. Than the generic model is not enough. For example capacitance between windings should also be considered. But i am confused abit about core. But as you said even we consider harmonics it would still be resistive due to inphase V and I.Baluncore said:A power transformer is specified for operation at a fixed frequency.
The real power loss is in phase with the voltage, not in quadrature as VAR.
Core loss is when flux change is greatest, which is in phase with the voltage, so must be resistive.
I took a closer look only to the 1st paper, I agree with the analysis there.Babadag said:Core losses depend on frequency. See attached articles.
Yes! @Baluncore nailed it with his reference to the phase of the impedance in your modelling of the losses.Baluncore said:The real power loss is in phase with the voltage, not in quadrature as VAR.
@Baluncore and @DaveE both gave good advice. I would like to add that the imaginary portion of the power also cause real power losses via the resistance in the wiring that brings current to the device in question.DaveE said:When you do the power calculation (integration of voltage times current) the imaginary, out of phase, part sums to zero. This is ultimately a definition IMO, if there's power dissipation, it has to be the resistive part, that's how the math works out.
Transformer modelling for harmonic studies is a process of creating a mathematical model of a transformer to analyze its response to harmonic currents and voltages. This is important for understanding the impact of harmonics on power systems and ensuring the safe and efficient operation of transformers.
Harmonics are unwanted frequencies that can cause disturbances in power systems, leading to equipment damage and power quality issues. Transformer modelling allows us to predict the behavior of transformers under different harmonic conditions and design solutions to mitigate any negative effects.
The key parameters considered in transformer modelling for harmonic studies include the transformer's impedance, inductance, capacitance, and resistance. These parameters can be affected by the presence of harmonics and can help us understand the transformer's behavior under different harmonic conditions.
Transformer modelling for harmonic studies is typically performed using specialized software programs that can simulate the behavior of transformers under different harmonic conditions. These programs use mathematical equations and algorithms to create a virtual model of the transformer and analyze its response to harmonics.
The benefits of transformer modelling for harmonic studies include a better understanding of the impact of harmonics on transformers, the ability to design and implement effective solutions to mitigate harmonics, and improved power quality and reliability in power systems. It also allows for cost-effective and efficient design of transformers for specific harmonic conditions.