SVPWM Generator (2-Level)

(To be removed) Generate pulses for SVPWM-controlled two-level converter

The Specialized Power Systems library will be removed in R2026a. Use the Simscape™ Electrical™ blocks and functions instead. For more information on updating your models, see Upgrade Specialized Power System Models to use Simscape Electrical Blocks.

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Libraries:
Simscape / Electrical / Specialized Power Systems / Power Electronics / Power Electronics Control

Description

The SVPWM Generator (2-Level) block generates pulses for three-phase two-level DC/AC converters using the space-vector pulse width modulation (SVPWM) technique.

The converter switches are represented by the following equivalent circuit:

As shown in the following figure, the objective of the SVPWM technique is to approximate the reference voltage vector (U_ref) instantaneously by combining the switching states corresponding to the basic space vectors.

More precisely, for every PWM period, the reference vector U_ref is averaged by using its two adjacent space vectors (U₃ and U₄ in the figure) for a certain duration of time and a null vector (U₇ or U₈) for the rest of the period.

Vector	Q1	Q3	Q5
U1	1	0	0
U2	1	1	0
U3	0	1	0
U4	0	1	1
U5	0	0	1
U6	1	0	1
U7	0	0	0
U8	1	1	1

The block implements two symmetrical switching patterns [1]:

Pattern #1: With this pattern, known as Software-Determined, each PWM channel switches twice per every PWM period.

Pattern #2: With this pattern, known as Hardware-Determined, one PWM channel remains constant for the entire PWM period. Consequently, the number of switching times for this pattern is less than pattern #1. As a result, switching losses are reduced with Pattern #2.

Characteristics

Sample Time	Specified in the Sample Time parameter Continuous if Sample Time = 0
Scalar Expansion	No
Dimensionalized	No

Ports

Input

|U| — Magnitude of rotating reference vector

Magnitude of the rotating reference vector U_ref.

Dependencies

To enable this port, set Data type of input reference vector (Uref) to Magnitude-Angle (rad).

⦟U — Phase of rotating reference vector

Phase, in radians, of the rotating reference vector U_ref.

Dependencies

To enable this port, set Data type of input reference vector (Uref) to Magnitude-Angle (rad).

Uα — Alpha components of rotating reference vector

Alpha components of the rotating reference vector U_ref.

Dependencies

To enable this port, set Data type of input reference vector (Uref) to alpha-beta components.

Uβ — Beta components of rotating reference vector

Beta components of the rotating reference vector U_ref.

Dependencies

To enable this port, set Data type of input reference vector (Uref) to alpha-beta components.

Output

P — Pulse signals used to fire self-commutated devices

Six pulse signals to fire the self-commutated devices (Q1 to Q6) of a converter device.

Parameters

To edit block parameters interactively, use the Property Inspector. From the Simulink^® Toolstrip, on the Simulation tab, in the Prepare gallery, select Property Inspector.

Data type of input reference vector (Uref) — Type of reference vector

Magnitude-Angle (rad) (default) | alpha-beta components | Internally generated

Specify the type of reference vector.

When set to Magnitude-Angle (rad) (default), the U_ref vector is specified by the following inputs:

|U| Magnitude of Uref (value between 0 and 1)

When set to alpha-beta components, the U_ref vector is specified by the Uα and Uβ inputs.

When set to Internally generated, the U_ref is no longer an input to the block. It is internally generated in order to control the converter output voltage as specified in the output voltage parameter.

Switching pattern — Switching pattern

Pattern #1 (default) | Pattern #2

When set to Pattern #1 (default), every device of the converter switches twice per every PWM period.

When set to Pattern #2, the status of one of the three arms stays constant (no switching) for the entire PWM period.

PWM frequency (Hz) — PWM frequency

2000 (default)

PWM frequency that determines the PWM period.

$$PWMperiod=1/PWMFrequency$$

Output voltage: [ Mag (0<m<1), Phase (degrees), Freq (Hz)] — Magnitude, phase, and frequency of output voltage

[0.8 -30 50] (default)

Magnitude, phase, and frequency of the output voltage of the two level converter controlled by the block. The magnitude of the fundamental component of the converter line-to-line output voltage is defined as

$$V_{LLrms}=m\times \frac{V_{dc}}{\sqrt{2}}$$

Dependencies

To enable this parameter, set Data type of input reference vector Uref to Internally generated.

Sample time — Sample time

0 (default)

Specify the sample time of the block, in seconds. Set to 0 to implement a continuous block.

References

[1] Yu, Z., Application Report SPRA524, Space-Vector PWM with TMS320C24x Using H/W & S/W Determined Switching Patterns, Texas Instruments, 1999.

Extended Capabilities

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

Version History

Introduced in R2013a