high frequency step-up transformer for h-bridge inverter

[binaryninja]

I am trying to design a h-bridge inverter. I've been referencing car inverter designs that input 12Vdc and output 110Vac/60Hz. Some of them boost the input voltage to around 100Vdc or so before feeding the inverter, which I was gonna do as well to help with the efficiency of the inverter.
When it comes to stepping up the output voltage to the 110VAC, it is my understanding that a high-frequency ferrite transformer is used. I've opened up a few car inverters and the transformers are pretty small. I want to do this as well. When it comes to finding a transformer that will work I'm assuming it is called a SMPS transformer (such as listed on Digikey). However, this is where I get stuck. I'd rather buy a transformer than make one. There has to be some available that are designing for this kind of application. Can someone please direct me in the right direction to obtain such a transformer. Specifically, what parameters should I be looking at?

If I'm way off track about a h-bridge inverter design or the usage of a high frequency transformer please correct me for I am a novice at these designs.

THANKS!

inverter specs:
Vin = 50-100VDC
Vout= 110VAC/60Hz
Pout= 200W

 

[WimRFP]

Hello,

I assume you want to make a true sine wave inverter. Such converters use a two-step approach.

An isolated transformer is required to step up the low voltage DC to about 180VDC. This DC to 180VDC converter can be a H-bridge type as well. You need more mosfets, but the transformer design is easier.

The second converter (that is fed from the 180VDC) makes the 110Vac via PWM (Pulse Width Modulation) of another H-bridge. This second inverter doesn't have a transformer, only filtering (with ferrite chokes and capacitors) to remove the switching products (20kHz...>1 MHz).

You need about 180…200VDC "bus" voltage as the peak value for 110VDC is about 155Vpk

Regarding the transformer, it is very unlikely that you can buy a transformer that fits your needs. So I think you have to design your transformer yourself. The design depends on: topology (flyback, forward, push pull, H-bridge), switching frequency, power requirements, etc.

As you are new to power electronics and magnetics design, you have to go a long way.

As you are working with potentially lethal voltages and power levels, safety must be taken into account also. What safety measures are applicable depends on the kind of application and the installation environment.

 

[vlee3131]

How to modify the input voltage of an car inverter?

I have a 12V to 200V inverter but I want to modify the circuit to make it to accept 100V and output the same. Do I have to change the transformer inside only or the rest of the circuit?

 

[mtwieg]

Re: How to modify the input voltage of an car inverter?

I have a 12V to 200V inverter but I want to modify the circuit to make it to accept 100V and output the same. Do I have to change the transformer inside only or the rest of the circuit?

You'll almost certainly need to do some modification to the electronics besides the transformer. Exactly what depends on how the inverter is built.