How to Simulate Inverter in Simulink: Step-by-Step Guide

To simulate an inverter in Simulink, use power electronics blocks like Universal Bridge or IGBT modules from the Simscape Electrical library. Connect these with a DC voltage source and load, then configure the switching signals using a PWM generator or control logic to mimic inverter operation.

Syntax

In Simulink, simulating an inverter involves these main components:

• DC Voltage Source: Provides input DC power.
• Universal Bridge Block: Represents the inverter switches (IGBTs or MOSFETs).
• PWM Generator: Creates switching signals to control the inverter.
• Load: AC load connected to inverter output.

The basic connection syntax is:

DC Voltage Source --> Universal Bridge --> Load

Control signals from PWM Generator connect to the Universal Bridge gate inputs.

matlab

simulink_model = 'inverter_simulation';
open_system(simulink_model);

Example

This example shows how to build a simple single-phase inverter simulation using Simulink blocks.

Steps:

• Add a DC Voltage Source block (e.g., 100 V).
• Add a Universal Bridge block configured for IGBTs.
• Add a Pulse Generator block to create PWM signals.
• Connect the PWM output to the gate inputs of the Universal Bridge.
• Add an RLC Load block to simulate the AC load.
• Run the simulation and observe the AC output voltage waveform.

matlab

% Create a new Simulink model
model = 'simple_inverter';
new_system(model);
open_system(model);

% Add DC Voltage Source
add_block('powerlib/Elements/DC Voltage Source',[model '/DC Voltage']);
set_param([model '/DC Voltage'],'Amplitude','100');

% Add Universal Bridge
add_block('powerlib/Elements/Universal Bridge',[model '/Universal Bridge']);
set_param([model '/Universal Bridge'],'BridgeType','IGBT');

% Add Pulse Generator for PWM
add_block('simulink/Sources/Pulse Generator',[model '/PWM Signal']);
set_param([model '/PWM Signal'],'Period','1e-3','PulseWidth','50','Amplitude','1');

% Add RLC Load
add_block('powerlib/Elements/RLC Load',[model '/Load']);
set_param([model '/Load'],'Resistance','10','Inductance','0.001','Capacitance','0');

% Connect blocks
add_line(model,'DC Voltage/1','Universal Bridge/1');
add_line(model,'Universal Bridge/1','Load/1');
add_line(model,'PWM Signal/1','Universal Bridge/2');

% Save and run simulation
save_system(model);
sim(model);

Output

Simulation runs successfully showing AC voltage waveform at load.

Common Pitfalls

Common mistakes when simulating inverters in Simulink include:

• Not configuring the Universal Bridge block correctly for the switch type (IGBT, MOSFET, etc.).
• Incorrect PWM signal timing or amplitude causing no switching or continuous conduction.
• Missing connections between PWM signals and gate inputs.
• Not setting the DC source voltage or load parameters properly, leading to unrealistic results.
• Ignoring solver settings; use a fixed-step solver with a small step size for power electronics.

matlab

%% Wrong PWM amplitude example
set_param([model '/PWM Signal'],'Amplitude','0.5'); % Too low, switches may not turn on

%% Correct PWM amplitude example
set_param([model '/PWM Signal'],'Amplitude','1'); % Proper amplitude for switching

Quick Reference

Summary tips for inverter simulation in Simulink:

• Use Universal Bridge for easy inverter modeling.
• Generate PWM signals with Pulse Generator or PWM Generator blocks.
• Set solver to fixed-step with small step size (e.g., 1e-6) for accuracy.
• Check all block parameters: voltage, load, switching frequency.
• Visualize output with Scope or Simscape Logging.

Key Takeaways

Use the Universal Bridge block with proper switch type to model the inverter.

Control the inverter switches with PWM signals connected to gate inputs.

Set solver to fixed-step with a small step size for accurate simulation.

Configure DC source and load parameters realistically for valid results.

Verify all connections and signal amplitudes to avoid simulation errors.