The post explains a simple 3 phase solar submersible pump inverter circuit which can be made by configuring a few ICs and a few power devices. The idea was requested by Mr. Lufono and Mr. Sami.
Solar Inverter for 3 Phase Pumps
First of all i must say thanks to you and Mr. Lufono, i have many solar projects of solar tube well and want to make a three phase inverter and i connected 14 to 23 solar panels of 250 watts every solar panel 31 volts 8amp in series than i have 450 vdc to 750 vdc .my submersible pumps 5.5kw to 7.5 kw 3phase 220v and 380v 3phase. plz i also request that in the circuit auto motor speed control also needed .means when solar panel voltages up or down with the time and sunlight motor speed also adjust automatically.if igbt needed GP50R12KT3 or other no problem .plz help me so so thanks .
The Circuit Design
I have already explained a simple single chip 3 phase full bridge inverter circuit, the same IC can be used for the proposed solar pump inverter circuit. The standard configuration of the 3 phase driver IC IRS2330 can be seen below:
However since the mentioned 3 phase driver requires a dedicated 3 phase signal across its triggering inputs marked as HIN....LIN, it would be first important to learn about a simple 3 phase signal generator circuit using opamps which could be integrated with the above design for the intended outcome..
It doesn't need to be a sine wave 3 phase signals a simple square wave 120 degree phase shift PWM generator could be used for the application, as illustrated below:
3-Phase Generator Schematic
The above 3 phase generator circuit can be further modified in the following manner so that it can be fed to the 3 phase driver IC shown in the first image:
Using BJT Buffer Stage
Here we see how the outputs from the 3 phase generator opamps are buffered using transistor inverters for producing the required 3 out-of-phase channels for the HIN...LIN inputs of the IRS2330 3 phase inverter driver IC.
The load connected with the driver mosfets or IGBTs now would receive a square wave 3 phase operating voltage, which could be a submersible pump motor in our application as per the request.
In case the IC IRS2330 looks difficult to acquire in the local market, the following cheaper half wave solar submersible inverter circuit concept could be implemented, although with 50% less wattage efficiency.
The BJTs could be replaced with appropriately rated mosfets or IGBTs...rest of the configuration is pretty straightforward and does not need much explanation.