# Nonlinear Inductor

Discrete nonlinear inductor

• Library:
• Simscape / Electrical / Specialized Power Systems / Passives

• ## Description

The Nonlinear Inductor block represents a time-varying inductor. It implements a discrete variable inductor as a current source. The inductance is specified by a monotonically increasing flux linkage-current characteristic.

When you use a Nonlinear Inductor block in your model, set the powergui block Simulation type to `Discrete` and select the Automatically handle Discrete solver and Advanced tab solver settings of blocks parameter in the Preferences tab. The robust discrete solver is used to discretize the electrical model. Simulink® signals an error if the robust discrete solver is not used.

### Equations

The block uses the following equations for the relationship between the voltage, v, across the device and the current through the inductor, i, and the flux linkage:

`$v=\frac{d\left(phi\right)}{dt}$`

`$phi=L\ast i=flux\text{\hspace{0.17em}}linkage.$`

## Ports

### Conserving

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Specialized electrical conserving port associated with the inductor positive voltage.

Specialized electrical conserving port associated with the inductor negative voltage.

## Parameters

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Robust integration method used by the block. The discrete solver method is automatically set to `Trapezoidal` when, in the powergui block, in the Preferences settings, you select Automatically handle discrete solver and Advanced tab solver settings of blocks.

The `Trapezoidal` robust solver is slightly more accurate than the `Backward Euler` robust solver, especially when the model is simulated at larger sample times. The `Trapezoidal` robust solver may produce slight damped numerical oscillations on machine voltage in no-load conditions, while the `Backward Euler` robust solver prevents oscillations and maintains good accuracy.

Resistance specified by a monotonically increasing flux linkage-current characteristic, specified as a 2-by-n matrix where n is greater than or equal to 2.

Measurement type. Select `Flux, Imag` to measure the flux and magnetization current of the nonlinear inductor. Place a Multimeter block in your model to display the selected measurements during the simulation.