Circuit Analysis: Fully Understand The Basic Laws of it. Do not expect Circuit Simulator will do it for you, these are complementary tools.

The following are the most Popular Circuit Simulators available in the market. Let us start searching in YouTube: Web Based/Online or Stand Alone versions

1. Exploring Circuit Simulation Tools: Online & Offline. Watch here

There are very "friendly" Window Based version with Virtual Instruments

• TinkerCAD: Visit the website a create an account Professors here, Students here
• Visite la página del sitio oficial y crea una cuenta para Profesores aquí y para Estudiantes aqui

• Using Oscilloscope and Function Generator in TinkerCAD. Watch here
• Introduction to Tinkercad Circuits & Breadboarding - Part 1. Watch here
• Half wave Rectifier Circuit simulation in TinkerCAD. Watch here
• Forward bias characteristics PN diode. Watch here

more searching on YouTube for keyword: TinkerCAD circuit simulator, Rectifiers, Boster, Switching PS

Classic *SPICE simulator: Freeware from Analog Devices: LT Spice. SPICE-based analog electronic circuit simulator computer software, produced by semiconductor manufacturer Analog Devices. It is the most widely distributed and used SPICE software in the industry.

1. Full Wave Rectifier. Watch here
2. Single Phase Inverter (Simulation, FFT, Harmonics) for AC Motors. Watch here
3. Tri-Phase Rectifier with Delta Wye connection.
4. 12-Pulses Rectifier very Popular in Subway Systems. Read more
5. Simplification without Sacrificing Quality or Safety is a Wonderful Technique: Power Converters: for Electrolyzer, Rectifier with Boosting Technique all in one Stage/Spice Simulated. Read more
6. Green Hydrogen Revolution Power Converter Topologies for Electrolyzers & SPICE Simulation. Read here
7. 12‐Pulse Diode Bridge Rectifier with a Three‐Phase Interleaved Buck Converter. Read more

*SPICE is an acronyms for Simulation Program with Integrated Circuit Emphasis

More about SPICE: read here

• QSPICE - "The best free circuit simulator? "Watch here
• QSPICE™ for analog and mixed signal simulation gives power designers the ability to evaluate their designs with complete confidence in the results. Read more
• Get QSPICE registration is required, Read more

Simulation in Power Electronics

• Powerful Knowledge 13 - Simulation in Power Electronics. Watch here
• Power Electronics: Simulation of Power Electronic Circuit using PSIM. Watch here
• PSIM freeware download from here

The Following list shows some of the Power Converters that can be simulated with PSIM demo limited to 6000 points:

AC to DC Converters:

• 3-Phase Half-Wave Rectifier:

• 3-Phase Full-Wave Rectifier

AC to AC Converters:

stay tuned!

DC to AC Converters:

DC to AC Two Phases (Demos is restricted to 6000 points):

DC to DC Converters:

Booster:

"PLECS® tools can be applied to many disciplines of Power Electronics engineering. Conceived with a top-down approach in mind"

• PLECS DOWNLOAD trial license from here
• PLECS standalone version from here and Web Based Version here
• PLECS Coder: "Generate C Code from a PLECS Model" Read more
• PLECS Blockset: "The Power Electronics Toolbox for Simulink" Read more

Above mentioned are few simulation tools available, are plenty of them out there.

Note: Freeware are version for student and teacher, when you get familiar with it you could become a potential user/customer, at the end there is nothing real free.