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6-Phase Inverse VSD Transform

Compute vector space decomposition (VSD) based inverse transformation on orthogonal inputs

Since R2024b

Libraries:
Motor Control Blockset / Controls / Math Transforms
Motor Control Blockset HDL Support / Controls / Math Transforms

Description

The 6-Phase Inverse VSD Transform block applies inverse vector space decomposition (VSD) transform on the orthogonal inputs (α, β, x, y, z+, and z-) to compute the six-phase outputs (a1, b1, c1, a2, b2, and c2).

The six orthogonal input components belong to the following three subspaces:

  • α-β subspace (containing α and β components)

  • x-y subspace (containing x and y components)

  • Zero sequence subspace (containing z+ and z- components)

The block outputs the six signals as two sets of three-phase signals.

You can use the block to determine the six-phase stator voltages or currents of an asymmetric or a symmetric six-phase permanent magnet synchronous motor (PMSM) using the six orthogonal input components. For example, you can use this block to determine the reference six-phase stator voltages from the α, β, x, and y reference voltage components generated by the current PI controllers. Therefore, you can use this block to implement field-oriented control (FOC) of an asymmetric six-phase PMSM. For more information, see Field-Oriented Control of Six-Phase PMSM.

Six-phase motors have different configurations based on the spatial angle (or spatial shift) between the two sets of three-phase windings. An asymmetric six-phase PMSM uses a spatial angle of 30 electrical degrees, whereas a symmetric six-phase PMSM uses a spatial angle of 60 electrical degrees.

The following image shows the comparison between input signals α and β as well as the output signals a1 and b1.

For more information about the block algorithm, see Algorithm.

Examples

Ports

Input

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Six axis orthogonal input components (α, β, x, y, z+, and z-) in the following three subspaces:

  • α-β subspace (containing α and β components)

  • x-y subspace (containing x and y components)

  • Zero sequence subspace (containing z+ and z- components)

Data Types: single | double | fixed point

Output

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First set of three-phase outputs, such that phase a1 axis aligns with the α axis. For a six-phase PMSM, this port outputs the three-phase stator voltages or currents belonging to the first three-phase winding set.

Data Types: single | double | fixed point

Second set of three-phase outputs. For a six-phase PMSM, this port outputs the three-phase stator voltages or currents belonging to the second three-phase winding set.

Data Types: single | double | fixed point

Parameters

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Select this parameter to enable the block to use power invariant transformation. If you clear this parameter, the block uses amplitude invariant transformation.

Select the type of six-phase PMSM for which you want to compute the inverse VSD transformation.

Algorithms

The following equations describe the inverse VSD transformation on the six orthogonal input components for an asymmetric PMSM.

[a1b1c1a2b2c2]=(σ)[1010101232123210123212321032123212013212321201010101]×[αβxyz+z]

where,

σ=1           (for amplitude invariant transformation)  =13       (for power invariant transformation)

The following equations describe the inverse VSD transformation on the six orthogonal input components for an symmetric PMSM.

[a1b1c1a2b2c2]=(σ)[1010101232123210123212321012321232011010011232123201]×[αβxyz+z]

where,

σ=1           (for amplitude invariant transformation)  =13       (for power invariant transformation)

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

Fixed-Point Conversion
Design and simulate fixed-point systems using Fixed-Point Designer™.

Version History

Introduced in R2024b