pv system

i designed the system include pv pannel and inverter (DC-AC) controller. the aim of this design control the voltage by controlling the reactive power ..... i have three question?
1. is there any problem if  i dont use battery...
2. if i dont  use DC chopper
3.and actually i dont know in a practical the out put of pv pannel is compatible by system or no? means may i have over power in system which damage my system in the case of no battery in system

Comments

  • BB.BB. Super Moderators, Administrators Posts: 29,973 admin
    Welcome to the forum Ilnaz.

    There is a guy that connected a solar panel directly to an AC inverter... There is a few issues that can make it a bit of problem.

    First is that a "12 volt" solar panel can output 17 to 22 volts pretty easily and most 12 VDC inverters will shut down if the DC input is over ~15-16 volts.

    Another issue is that when the sun goes down, or if the AC inverter tries to draw too much current, the DC voltage from the solar panel will drop below ~10.5 volts... Many AC inverters will shutdown and need the DC input voltage to drop to near zero volts and brought backup up > 12 VDC to reset the low voltage alarm.

    Here is a product from MW&S (note: they are a competitor to the host of our forum):

    http://store.mwands.com/charge-controllers/12-volt-suntaqe-pwb-charge-controller-with-inverter/

    And a older discussion of what we guessed he was doing:

    http://forum.solar-electric.com/discussion/comment/300388/#Comment_300388

    I don't know anything else about the MW&S product (good or bad)--But it does appear to do what it was designed to do (power smaller AC inverters directly from a "12 volt" solar panel).

    There are no specifications on the "magic box"--So you would need to contact the vendor directly as to its limitations.

    If you can power your small AC loads directly during the middle of a sunny day from a solar panel+the box satisfactorily without a battery bank--Might be worth a try.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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