Engee documentation

Variable Inductor

Linear variable inductance coil.

variable inductor (2)

Description

The Variable Inductor unit is a linear inductance coil model with time-variable inductance.

The block has the option of selecting the equation for the relationship between the voltage and the current through the inductance coil when the inductance at the L port is equal to .

The Equation parameter determines which of the following equations the block uses:

  • Use the equation above if inductance is defined as the ratio of magnetic flux Ф to steady-state current:

  • Use the equation above if the inductance is defined as the local gradient of the flux-current curve for a given current:

A conductance is included in the block parallel to the AC inductor. It can be used to represent the total conductance of the inductor insulation. The use of conductance may be necessary to prevent computational errors in some circuit topologies, such as when a Variable Inductor block is connected in series with another inductor coil block without parallel conductance.

Ports

Input

L - inductance
scalar

Input signal determining the value of inductance, Gn.

The inductance must be finite, greater than zero and continuous (no step changes).

Non-directional

+ - positive
electricity

Electrical port, represents the positive terminal of the coil.

- is the negative
electricity

Electrical port, represents the negative terminal of the coil.

Parameters

Equation - block inductance equation
V = L*dI/dt + dL/dt*I (by default) | V = L*dI/dt

Select one of the following options for the inductance equation in the component:

  • V = L*dI/dt + dL/dt*I - if inductance is assumed to be the ratio of magnetic flux to steady-state current. This option is used by default.

  • V = L*dI/dt - if it is assumed that inductance is the local gradient of the flux-current curve at a given current.

Minimum inductance L>0 - the minimum inductance of the coil
1e-6 Gn (by default).

Lower limit on the value of the signal on the L port. This limitation prevents the signal from reaching a value that makes no physical sense.

Parallel conductance - parallel conductance
1e-9 1/ohm (by default).

The value of the conductance set in parallel to the variable inductance coil.

Initial current - initial value of current
`0 (By default)

Initial current value, A.

Dependencies

This parameter is only used when V = L*dI/dt is selected for the Equation parameter.

Initial magnetic flux - initial value of magnetic flux
0 (By default)

Initial magnetic flux value, Vb.

Dependencies

This parameter is only used when V = L*dI/dt + dL/dt*I is selected for the Equation parameter.