Inductive and capacitative loads

nickdearing88nickdearing88 Registered Users Posts: 100 ✭✭✭
Hi everyone.

I have a good understanding of electricity basics, especially with DC current. I built a few simple circuit boards in college. Since AC current can be much more complex, I've been trying to learn more about inductive and capacitative loads, impedance, waveform, etc.

I've been reading articles like this one, posted by @mcgivor in another post:

When power is consumed and returned in inductive and capacitative loads, how does an inverter handle this "returned power" with respect to the DC side?

For example, let's say a capacitor draws 100w between 0 - 90 degrees then returns 100w between 90 - 180 degrees of the sine wave. The "real power" consumed would be zero, no net change. In the case of an off-grid system, is the inverter pulling the 100w then returning it to the battery? I'm eliminating the inverter tare load and efficiency for simplicity.
Current system: 8-100w Renogy panels mono/poly, 2 strings of 4 panels in series - 24v 100Ah AGM Battleborn LiFePO4 batteries - Morningstar MPPT40 CC - 1500W Samlex PSW inverter


  • EstragonEstragon Registered Users Posts: 4,495 ✭✭✭✭✭
    My (limited) understanding is the "real power" of zero is useful work. In a real circuit the inverter still has to create the current, with associated losses, so less than 100% is returned to the battery.
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • mike95490mike95490 Solar Expert Posts: 9,321 ✭✭✭✭✭
    this article of Operation
     is a very good  read about power factor loads (inductive, capacitive)

    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    gen: ,

  • jonrjonr Solar Expert Posts: 1,386 ✭✭✭✭
    It depends on the inverter design.   Some store the energy in DC capacitors, some can put it back into the battery.

    I am available for custom hardware/firmware development

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