Can you use a BTS7960 43A module as driver for a SPWM transformer inverter

[Piet de Pad]

Hi all,
I have a crazy idea, the BTS7960 43A is a PWM motor driver module. It's maximum PWM frequency is 25Khz, and the build in MOSFETS have a quite low RDSon. So I was wondering if I can use this module as a driver for a transformer to make a 12/24Vdc to 120Vac inverter.I want to use an Arduino together with this module to create a 25KH SPWM driver and use a standard transformer.Let me know what you think of this idea and if this is possible or maybe why this is not a good idea. Has anyone seen this somewhere at the internet and can you give me some links.
Thanks

 

[Easy peasy]

With enough knowledge - almost anything is possible.

 

[mtwieg]

I don't see why not, but you will need to put some sort of line filter between the driver and the transformer.

 

[Piet de Pad]

ee why not, but you will

What I understand from others is that the output 120Vac needs a 2.2uF capacitor to smoothen the sine wave. Thanks for your response.

 

[mtwieg]

What I understand from others is that the output 120Vac needs a 2.2uF capacitor to smoothen the sine wave. Thanks for your response.

By "line filter" I meant a series inductance followed by some shunt capacitance, which will filter off the 25kHz PWM signal from the driver.

It's possible that the leakage inductance of the transformer may effectively act as the inductor, so simply adding a capacitor on the secondary side would complete the filter. Depends greatly on the specific transformer though, caution is advised.

Also you will need to be careful that the duty cycle on the two half bridges is balanced very precisely, otherwise you will end up dumping lots of DC current into the primary.

 

[Piet de Pad]

By "line filter" I meant a series inductance followed by some shunt capacitance, which will filter off the 25kHz PWM signal from the driver.

It's possible that the leakage inductance of the transformer may effectively act as the inductor, so simply adding a capacitor on the secondary side would complete the filter. Depends greatly on the specific transformer though, caution is advised.

Also you will need to be careful that the duty cycle on the two half bridges is balanced very precisely, otherwise you will end up dumping lots of DC current into the primary.

Thanks. yes that capacitor seems normally to be enough. If not a LC filter is needed. The problem of flux walking as a result of the difference in V*dt is known to me and yes come very precise.

I have a question about this. If the volt seconds are not equal for both half cycles of the AC, a DC current component is introduced. The flux will walks in direction of saturations and the current in one half cycle will increase and be different compared with the current in the other half of the cycle. Question: Is the mismatch in volt seconds automatically balanced as soon as the effects of saturation starts to effect the magnetic field? Meaning, does the effects of saturation result in a negative feed back on the difference in volt seconds and automatic balance the Volt seconds per half period?

I ask this question because if this is true the strength of the magnetic field in the core of the transformer should be big enough to have a low magnetic loss but not to small to keep the flux walk close to center of the magnetic HB diagram.

Any idea about this.?