Engee documentation

Inductive Rotor Position Sensor

Inductive rotor position sensor with four inductance coils.

blockType: AcausalElectricPowerSystems.Sensors.InductiveRotorPosition

Path in the library:

/Physical Modeling/Electrical/Sensors & Transducers/Inductive Rotor Position Sensor

Description

The Inductive Rotor Position Sensor unit uses eddy current loss theory to obtain rotor position data. The sensor consists of four planar coils and a conductive disc that detect the rotor position. The sensor disc has a sinusoidal shape and is made of conductive material. The distance between the four flat coils is equivalent to 90 degrees of one cycle.

inductive rotor position sensor 1

Equations

The voltages between the sensor elements are described by the equations:

Where:

  • - cosine voltage,

  • - sinusoidal voltage,

  • and are voltage amplitudes for axes and , reflecting the sensitivity mismatch,

  • and - voltage offsets for axes and ,

  • - number of pole pairs,

  • - rotor angle,

  • - quadrature error,

  • - instability coefficient.

The angle decoding is calculated by the formula:

This figure shows the effect of the volatility factor:

inductive rotor position sensor 2

Variables

To set priority and initial target values for block variables before calculation, use the parameters in the Initial Targets section.

Ports

Non-directional

R - encoder shaft
`rotational mechanics

Mechanical rotation port corresponding to the positive connection of the sensor.

C - sensor housing
`rotational mechanics

Rotational mechanical port corresponding to the negative (reference) connection of the sensor.

yp is the positive terminal of the y-axis
electricity

The electrical port associated with the positive terminal of the y-axis.

Dependencies

To enable this port, set Output interface to Electrical connections.

yn is the negative terminal of the y-axis
electrical

The electrical port associated with the negative terminal of the y-axis.

Dependencies

To enable this port, set Output interface to Electrical connections.

xp is the positive terminal of the x-axis
electrical

The electrical port associated with the positive terminal of the x-axis.

Dependencies

To enable this port, set Output interface to Electrical connections.

xn is the negative terminal of the x-axis
electrical

The electrical port associated with the negative terminal of the x-axis.

Dependencies

To enable this port, set Output interface to Electrical connections.

Output

Angle - angle of rotation, rad
scalar

Angle of rotation of the magnetic field in the plane - , returned as a scalar.

Dependencies

To enable this port, set the Output interface parameter to Decoded angular position.

Parameters

Number of pole pairs - number of pole pairs
2 (by default) | `scalar `

Number of pole pairs.

X-axis voltage amplitude - x-axis voltage amplitude
2.5 V (by default) | scalar

x-axis voltage amplitude.

Y-axis voltage amplitude - y-axis voltage
2.5 V (by default) | scalar

Y-axis voltage amplitude.

X-axis voltage offset - x-axis voltage offset
0 (By default) | scalar

The potential difference when an electric current flows through a conductor in the absence of an external magnetic field along the x-axis.

Y-axis voltage offset - y-axis voltage offset
0 (by default) | scalar

The potential difference when an electric current flows through a conductor in the absence of an external magnetic field along the y-axis.

Quadrature error - quadrature error
0 (By default) | scalar

The magnitude of the quadrature error. Quadrature switching can reduce offset errors.

Tumbling coefficient - instability coefficient
0 (By default) | scalar

Instability coefficient.

Output interface - interface for decoded information
Electrical connections (by default) | Decoded angular position.

Interface for decoded information, available values:

  • Electrical connections (by default).

  • Decoded angular position.

Initial Targets

Rotor angle - initial value of rotor angle
0 (by default) | scalar

Initial value of the rotor angle.