does an inverter has transformer in it?

i wonder that the grid tied solar inverter has transformer in it?i see an inverter at shop, the input is 12vdc and output is 240vac, how it jump up from 12vdc to 240vac?

Yes. Either a 50 Hz transformer along with a low voltage inverter, or a small high frequency transformer as part of a 12 to 300 V DC/DC converter feeding a high voltage inverter.

Yes, it has a transformer in it.

To make the "jump up" - boost the voltage - there are two methods:

1) Convert the 12VDC to 50Hz AC and feed that to a 50Hz step up transformer. DC to AC conversion is most commonly done using push-pull or full-bridge converter, typically using MOSFETs.

2) Convert the 12VDC to high frequency (20kHz to 100kHz is a common range) and feed that to a step up ferrite transformer. The low voltage is stepped up to high voltage high frequency AC, which is rectified to DC using ultrafast recovery diodes and filtered with an LC filter. The high voltage DC is then converted to AC using a full-bridge converter, using MOSFETs or IGBTs.

If the inverter you mention, is heavy and bulky, it uses method (1). If it is rather light, it uses method (2). Of course, this is just a quick "test methodology" as mass/weight isn't the best "sure shot" way to determine it since the mass/weight could be affected by other components.

Hope this helps.
Tahmid.

A lot of grid tied inverters (1kW - 5kW) are " transformerless" these days and the whole solar panel string is effectively connected to the mains via the inverter - hence the panels and their wiring must be done by licensed electricians, and the panel insulation also up to standard, as large installations of panels run from 100V - 550V no load, there is not a lot of difference between mains and these high DC voltages, the transformerless inverters (boost + H bridge inverter) are more efficient and lighter than a unit with a 50/60Hz or even a switchmode transformer...

Transformerless topology (using a boost inductor instead of a transformer) works for solar strings but won't be a good idea for a 12V/230V inverter, because switching losses would be unpleasantly high.

Orson Cart said:

A lot of grid tied inverters (1kW - 5kW) are " transformerless" these days and the whole solar panel string is effectively connected to the mains via the inverter - hence the panels and their wiring must be done by licensed electricians, and the panel insulation also up to standard, as large installations of panels run from 100V - 550V no load, there is not a lot of difference between mains and these high DC voltages, the transformerless inverters (boost + H bridge inverter) are more efficient and lighter than a unit with a 50/60Hz or even a switchmode transformer...

Click to expand...

These are efficient and possible because of the low difference in the solar output voltage and the desired output voltage. However, in cases where the input is low voltage - 12V as the OP mentions or even 24V,etc - using a transformerless boost converter is not an efficient solution. Think of the high peak currents, low duty cycles, high losses and in the end using a two-stage inverter with a ferrite transformer-based first stage is the better solution. And another obvious disadvantage would be lack of isolation between the 12V and the high voltage DC.

I think Orson was talking of grid tied inverters, just as a point of difference, and not the smaller 12 or 24V input ones...

Anna Conda said:

I think Orson was talking of grid tied inverters, just as a point of difference, and not the smaller 12 or 24V input ones...

Click to expand...

Yes, of course. He was talking about large grid tied inverters with high voltage inputs. There are of course smaller grid tied inverters with low voltage inputs. Point was that, non-isolated boost converters work for high voltage inputs such as the ones he mentioned. However, they aren't a good solution for low voltage input inverters.

microchip and many more have done this topology.

**broken link removed**

microchip and many more have done this topology

Click to expand...

Yes, it's using high frequency transformers.