Name: how inductor current stores magnetic energy
Uploaded: 2024-04-11T12:48:39.000Z
Duration: 1 min 16 s
Channel: JoVE

K12 Standards

Texas Essential Knowledge and Skills

High School

Chemistry and Physics

IPC.6

IPC.6.A

Energy Stored in Inductors

An inductor is designed to store energy in its magnetic field, which is generated by the current flowing through its coils.
When the current is constant, the voltage across the inductor is zero, causing it to behave as a short circuit for direct current.
The energy stored within an inductor equals the integral of the instantaneous power delivered over time.
By integrating within the limits, an expression for the stored energy consisting of two terms is obtained. The second term is zero, considering the initial condition where no current flowed through the inductor.
Ideal inductors do not dissipate energy, allowing the stored energy to be retrieved later.
However, non-ideal inductors exhibit winding resistance, which originates from the conductor&#39;s coils and is presented in series with the inductance.
Although this winding resistance can lead to energy dissipation, it is typically so small that it can be neglected in practical scenarios.
Non-ideal inductors also exhibit winding capacitance attributable to capacitive coupling between the conducting coils. However, this winding capacitance is typically negligible except at high frequencies.

energy stored in inductors

An inductor is ingeniously crafted to accumulate energy within its magnetic field. This field is a direct result of the current that meanders through its coiled structure. When this current maintains a steady state, there is no detectable voltage across the inductor, prompting it to mimic the behavior of a short circuit when faced with direct current.
In terms of gauging the energy stored within an inductor, it is equivalent to the integral of the power delivered at every individual moment, all accumulated over a specific duration of time. Mathematically, energy stored in an inductor is expressed as
<img alt="w = 1/2Li^2 formula, physics equation; kinetic energy in electric circuits; educational diagram" src="/files/ftp_upload/15089/15089_PT_Equation_1.svg" style="text-align: center; height: 34px;" data-altupdatedat="1761848533000" data-alt="Equation1" />
Where w is the energy stored in the inductor, L is the inductance and i is the current passing through the inductor.
Ideal inductors have a noteworthy characteristic - they do not dissipate energy. This trait allows the energy stored within them to be harnessed at a later point in time. However, this ideal scenario is slightly marred when dealing with non-ideal inductors.
Non-ideal inductors exhibit a phenomenon known as winding resistance. This resistance stems from the coils of the conductor and presents itself in series with the inductance. While this winding resistance has the potential to contribute to energy dissipation, it is typically so minuscule that it can be conveniently overlooked in practical applications.
Additionally, non-ideal inductors also display winding capacitance. This is due to the capacitive coupling that occurs between the conducting coils. However, this winding capacitance is usually so minute that it can be disregarded, except when dealing with high frequencies.

An inductor is designed to store energy in its magnetic field, which is generated by the current flowing through its coils.
When the current is constant, ...

Education

JoVE Core

Electrical Engineering

Unit 1

Energy Storage Elements

KEY TERMS AND CONCEPTS

how inductor current stores magnetic energy

An inductor stores energy in its magnetic field. That field is created by the current flowing through the coil. When the current stays steady, there is no measurable voltage across the inductor, so it behaves like a short circuit for direct current.

The energy stored in an inductor is the total power delivered over time. It can be written as a function of inductance, L, and current, i, where the stored energy increases with the current in the coil. This relationship helps explain how much energy is held in the magnetic field at any moment.

Ideal inductors do not lose energy, so the stored energy can be used later. Real inductors are not perfect, though. They may have winding resistance, which comes from the conductor coils and appears in series with the inductance. This resistance can cause some energy loss, but it is usually so small that it can be ignored in practice.

Non-ideal inductors can also have winding capacitance. This comes from capacitive coupling between the conducting coils. In most cases, this effect is very small as well, but it can matter at high frequencies.

How Inductor Current Stores Magnetic Energy

how-inductor-current-stores-magnetic-energy

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An inductor stores energy in its magnetic field. That field is created by the current flowing through the coil. When the current stays steady, there is no measurable voltage across the inductor, so it behaves like a short circuit for direct current. The energy stored in an inductor is the total power delivered over time. It can be written as a function of inductance, L, and current, i, where the stored energy increases with the current in the coil. This relationship helps explain how much...

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key terms and concepts

Learn how current in an inductor’s coil creates a magnetic field, stores energy, and why real inductors can also have winding resistance and capacitance.

How Inductor Current Stores Magnetic Energy | JoVE K12

JoVE Core Electrical Engineering offers easy-to-understand animated videos that cover fundamental concepts of electric circuits along with circuit analysis techniques. It incorporates first-order and second-order circuits using operational amplifiers and circuit transformation concepts. The inclusion of practical design examples and real-world applications through scientist-in-action videos adds significant educational value, making complex concepts accessible.

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How Inductor Current Stores Magnetic Energy

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