PWM Gate Signal Generator (Four-phase, Two-level)

Generate eight switch-controlling pulses for four-phase, two-level gating switching devices

Since R2026a

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  • PWM Gate Signal Generator (Four-phase, Two-level) block icon

Libraries:
Simscape / Electrical / Control / Pulse Width Modulation

Description

The PWM Gate Signal Generator (Four-phase, Two-level) block controls the switching behavior for a four-phase, two-level power converter. The block uses the gating times provided as inputs to generate eight switch-controlling pulses. You can obtain the gating time information using the PWM Timing and Waveform Generator (Four-phase, Two-level) block.

Sampling Mode

This block allows you to choose natural, symmetric, or asymmetric sampling of the modulation wave.

The PWM Gate Signal Generator (Four-phase, Two-level) block does not perform carrier-based pulse width modulation (PWM). Instead, the block uses the gating times to generate both the switch-controlling pulses and the modulation waveforms that the block outputs.

Carrier-based PWM is, however, useful for showing how the sampling mode that you select relates to the switch-on and switch-off behavior of the pulses that the block generates. A generator that uses a three-level, carrier-based PWM method:

  1. Samples a reference wave.

  2. Compares the sample to two parallel triangle carrier waves, separated by one level.

    A plot showing two parallel high‑frequency triangle carrier waves oscillating between +1 and −1, with a lower‑frequency sine wave drawn over them. The triangle waves are vertically separated by one level, and all signals share the same horizontal axis.

  3. Generates a switch-on pulse if a sample is higher than the carrier signal or a switch-off pulse if a sample is lower than the carrier wave.

To determine switch-on and switch-off pulse behavior, a three-level carrier-based PWM generator uses these methods to sample each of the triangle waves:

  • Natural — The sampling and comparison occur at the intersection points of the modulation wave and the carrier wave.

    A sine modulation wave is plotted over a high‑frequency triangle carrier wave. Sampling points appear at each intersection between the sine wave and the carrier wave. These points generate a corresponding PWM pulse train shown below the plot.

  • Asymmetric — Sampling occurs at the upper and lower boundaries of the carrier wave. The comparison occurs at the intersection that follows the sampling.

    A sine modulation wave is overlaid on a high‑frequency triangle carrier wave. Sampling occurs at both the upper and lower peaks of the carrier wave, marked with points. Comparison points appear at these intersections between the sine wave and the carrier, producing a PWM pulse train displayed below the plot.

  • Symmetric — Sampling occurs only at the upper boundary of the carrier wave. The comparison occurs at the intersection that follows the sampling.

    A sine modulation wave is overlaid on a high‑frequency triangle carrier wave. Sampling points appear only at the upper peaks of the carrier wave, with comparison taken at the next intersection between the modulation and carrier waves. A PWM pulse train generated from these events is displayed below the plot.

Ports

Input

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Switch-on gating time, specified as a vector of four elements, with one element for each phase.

Switch-off gating time, specified as a vector of four elements, with one element for each phase.

Output

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Eight pulse waveforms that determine the switching behavior in the attached power converter, returned as a vector.

Parameters

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Wave-sampling method. The sampling mode determines whether the block samples the modulation waveform when the waves intersect or when the carrier wave is at one or both of its boundary conditions.

Rate at which the switches in the power converter switch, in Hz.

Time interval between successive block executions, in seconds. To ensure adequate resolution in the generated signal, set this value to be less than or equal to 1/(50*Fsw), where Fsw is the value of the Switching frequency (Hz) parameter.

Extended Capabilities

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

Version History

Introduced in R2026a

See Also

Blocks