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C2000 Space Vector Generator

Duty ratios for stator reference voltage

Description

Replace the existing DMC blocks with MCB blocks for improved usability and future compatibility. It is recommended that you use blocks from Control Algorithm Design (Motor Control Blockset). While these blocks are not one-to-one replacements, they enable you to achieve the same functionality.

C28x DMC libC28x DMC lib equivalent in MCB
C2000 Clarke TransformationClarke Transform (Motor Control Blockset)
C2000 Inverse Park TransformationInverse Park Transform (Motor Control Blockset)
C2000 Park TransformationPark Transform (Motor Control Blockset)
C2000 PID ControllerPI Controller (Motor Control Blockset)
C2000 Ramp ControlPosition Generator (Motor Control Blockset)
C2000 Ramp GeneratorPosition Generator (Motor Control Blockset)
C2000 Space Vector GeneratorPWM Reference Generator (Motor Control Blockset)
C2000 Speed MeasurementSpeed Measurement (Motor Control Blockset)

This block calculates duty ratios that generate a given stator reference voltage using space vector PWM technique. Space vector pulse width modulation is a switching sequence of the upper three power devices of a three-phase voltage source inverter and is used in applications such as AC induction and permanent magnet synchronous motor drives. The switching scheme results in three pseudosinusoidal currents in the stator phases. This technique approximates a given stator reference voltage vector by combining the switching pattern corresponding to the basic space vectors.

The inputs to this block are

  • Alpha component — the reference stator voltage vector on the direct axis stationary reference frame (Ua)

  • Beta component — the reference stator voltage vector on the direct axis quadrature reference frame (Ub)

The alpha and beta components are transformed via the inverse Clarke equation and projected into reference phase voltages. These voltages are represented in the outputs as the duty ratios of the PWM1 (Ta), PWM3 (Tb), and PWM5 (Tc).

Note

The implementation of this block does not call the corresponding Texas Instruments® library function during code generation. The TI function uses a global Q setting and the MathWorks® code used by this block dynamically adjusts the Q format based on the block input. See Using the IQmath Library for more information.

  • C2000 Space Vector Generator block

References

For detailed information on the DMC library, see C/F 28xx Digital Motor Control Library, Literature Number SPRC080, available at the Texas Instruments Web site.