Hello everyone!
I am currently working with MMC and would like to simulate a half-bridge MMC (single-phase). Initially I just want to use one submodule per each arm. I have already completed the circuit. Problems:
Controlling the submodules
capacitor voltage balancing
can you please help me and thanks in advance

 

True, Some Gal Nitride FET models are available for ltspice. GAN inverters claiming 20% more efficiency are popular for small chargers.
Simulation is recommended, necessary because datasheet alone would be difficult at the present pace. Prior MMC developed with Matlab/Simulink.
Whatever the application, if the simulation matches the circuit or setup then troubleshooting will be easier and the development faster.

The true MMC used specialized semiconductors and capacitors and inductors,
The schematics do not show the physical components used in the stacks and phase control assembly. not necessarily to scale
In some designs ABB, pressure and thermal were very mechanical. Semiconductor 6, Phase 10, capacitors? 12 compression? 5



As power converter designs grew the term called power inverter, research dynamos still developing. Small scale went solid state and took off.
Each scale and category made significant achievement within the various types of applications most worked with Semiconductor research.
Some of the engineering was represented at the 2024 IEEE power conference Baltimore. There is a listing of company's product expositions.
The 2019 Conference of Europe/China had many MMC pioneers from all over. Among those was
Rainer Marquardt who was also awarded "Academic Emeritis" 2019 for MMC from his college in Munchen Germany.
In chronological order IEEE awarded these Electrical scientist: IEEE William E. Newell Power Electronics Award Recipients

 

Controlling the submodules
capacitor voltage balancing
can you please help me and thanks in advance

When you drive the Gate of a MOSFET you do not drive from Gate to Ground but you must drive from Gate to Source.
If you don't understand ask questions.

 

When you drive the Gate of a MOSFET you do not drive from Gate to Ground but you must drive from Gate to Source.
If you don't understand ask questions.

Hey! thanks for the answer. i tried that, but unfortunately it didn't work. can you explain more please.

 

Hey! thanks for the answer. i tried that, but unfortunately it didn't work. can you explain more please.

When a MOSFET sits on ground (Source=oV) You connect the gate drove from ground to Gate.
When you have a MOSFET-Source that is not at ground, you do not set the Gate drive on ground. The MOSFET does not know where ground is and do not care. The MOSFET turns on/off by the voltage from Gate to Source, not Gare to Ground.

Many MOSFETs have a max G-S voltage of +/-20V.
In the example here, M1 starts out with Source=20V. The Gate driver, sitting on ground, has +15V for turn on. The M1 sees a -5V from G-S. It will not turn on. The turn off voltage M1 sees is -20V.

I do not know why your circuit does not work. I think the two circuits in post #1 are not the same.

There is massive current flow in V2.

 

When a MOSFET sits on ground (Source=oV) You connect the gate drove from ground to Gate.
When you have a MOSFET-Source that is not at ground, you do not set the Gate drive on ground. The MOSFET does not know where ground is and do not care. The MOSFET turns on/off by the voltage from Gate to Source, not Gare to Ground.

Many MOSFETs have a max G-S voltage of +/-20V.
In the example here, M1 starts out with Source=20V. The Gate driver, sitting on ground, has +15V for turn on. The M1 sees a -5V from G-S. It will not turn on. The turn off voltage M1 sees is -20V.
View attachment 337047
I do not know why your circuit does not work. I think the two circuits in post #1 are not the same.

There is massive current flow in V2.
View attachment 337048

That's right, here is the right circuit
but it still doesn't work. The problem is in the control of the mosfets to realize the balancing of the capacitor voltages.

 

Hallo,

Ich habe die Schaltung noch einmal überarbeitet. Ich habe den MMC mit 2 Trägersignalen simuliert, die Ausgangsspannung ist schnell wie gewünscht (Rechteckspannung), das Problem ist der zu geringe Strom, die Sinusspannung nach dem LC-Filter ist ebenfalls zu gering. Noch eine Frage und zwar wie kann ich eine Delay Time setzen, damit die Mosfets nicht gleichzeitig Ein- bzw. ausgeschaltet werden.


Kann mir jemand dabei helfen oder mir eine Empfehlung geben? Vielen Dank

Mod: translated. Please use English text.

I've reworked the circuit. I simulated the MMC with two carrier signals, and the output voltage is as fast as desired (square wave). The problem is the current is too low; the sine wave voltage after the LC filter is also too low. One more question: How can I set a delay time so that the MOSFETs don't turn on and off simultaneously?

Can anyone help me with this or give me a recommendation? Thank you.