### Permanent Magnet

As an example of a magnetostatic problem, consider how to model a horseshoe-shaped permanent magnet. One way is to treat the entire magnet as a ferromagnetic material, where the two end sections are defined as being pre-magnetized in different and opposite directions.

### E-Core Transformer

This is the transient model of a single phase E-core transformer using a Multi-Turn Coil Domain. The model includes the effect of a nonlinear B-H curve in the core and shows how to connect the transformer model to the external circuits using Electric Circuit interface. The simulation is performed for two different cases; the first one with a unity turn ratio and second one with a turn ratio of ...

### Modeling of a 3D Inductor

Inductors are used in many applications for low pass filtering or for impedance matching of predominantly capacitive loads. They are used in a wide frequency range from near static up to several MHz. An inductor usually has a magnetic core to increase the inductance, while keeping its size small. The magnetic core also reduces the electromagnetic interference with other devices as the magnetic ...

### Computing Capacitance

A capacitor, in its simplest form, is a two terminal electrical device that stores electric energy when a voltage difference is applied across the terminals. The stored electric energy is proportional to the applied voltage squared and is quantified by the capacitance of the device. This model introduces a model of a simple capacitor, the electric field and device capacitance are solved for ...

### Magnetic Field of a Helmholtz Coil

A Helmholtz coil is a parallel pair of identical circular coils spaced one radius apart and wound so that the current flows through both coils in the same direction. This winding results in a uniform magnetic field between the coils with the primary component parallel to the axes of the two coils. Applications of Helmholtz coils range from canceling the earth’s magnetic field to generating ...

### Cable Tutorial Series

In this set of six tutorial models and associated documentation, you can investigate the capacitive, inductive, and thermal properties of a standard three-core lead-sheathed cross-linked polyethylene, high-voltage alternating current (XLPE HVAC) submarine cable (500 mm{:sup}2{:/sup}, 220 kV). The series is intended both for experts looking to get up to speed on how to model such applications in ...

### Voltage Induced in a Coil by a Moving Magnet

A magnet moving axially through the center of a coil will induce a voltage across the coil terminals. One practical application of this is in shaker flashlights, where the flashlight is vigorously shaken back and forth, causing a magnet to move through a multi-turn coil, which provides charge to the battery. In this model, the motion of a magnet through a coil is modeled, and the induced ...

### Permanent Magnet Motor in 3D

Permanent magnet (PM) motors are used in many high-end applications, such as in electric and hybrid vehicles. An important design limitation is that the magnets are sensitive to high temperatures, which can occur through heat losses caused by currents, particularly eddy currents. In this tutorial, an 18-pole PM motor is modeled in 3D to accurately capture eddy current losses in the magnets. ...

### Multi-Turn Coil Winding around a Ferromagnet

A demo model of a 50 Hz AC coil wound around a ferromagnetic (linear) core. The model is intended as a tutorial to show how to create a relatively complex geometry and set up the new Multi-Turn Coil features for the simulation. The model requires the Design module to fillet the edges of the block.

### Generator in 2D

In this model, a rotor with permanent magnets and a nonlinear magnetic material rotates within a stator of the same magnetic material. The generated voltage in windings around the stator is calculated as a function of time. COMSOL Multiphysics models the rotation with assemblies and identity pairs. The nonlinearity of the magnetic material is also taken into account using an interpolation ...