Hybrid Device for Small Solar System (1000W to 2000W)

[Revolutionist]

Hello!
i need some help from u guys i want to make a small device for my home solar system which perform smart switching and load transfer between solar system, battery bank and utility supply (AC supply 220V). System components : Solar Panels > Charge controller> Batteries>UPS

i wanna make a device which is connected after charger controller in sequence shown above and perform monitoring and switching tasks.
Well i have a rough algorithm about for working of this device which is as follows:
1-At DAY Time:
CASE I-When solar panels are generating enough power to support the load, UPS goes on inverting mode and start fetching power to load from solar panels (Utility and batteries stay idle in this condition).
CASE II- When solar panels are generating more power than required by load then excessive power will be transferred to to batteries to charge them.
CASE III- If weather is cloudy or Panels dont generate enough power then load will be transferred to utility supply and power generated by panels will b transferred towards batteries.
CASE IV- if Case III happens and utility is also not available then load will fetch the power from batteries (UPS will work in inverter mode)

2- Night Time CASE-I utility is available and load will fetch the power from utility
CASE-II utility is not available and load will fetch the power from batteries (UPS will work in inverter mode)
Simple schematics of device is attached with the thread

 

[BradtheRad]

First of all, you must ensure your AC will never go out to the street lines by mistake during a blackout. It could electrocute linemen working on wires. A transfer switch is necessary. If you want an automatic switch then you will pay more than for a manual switch.

As for how to handle everyday operation, are you certain it isn't easier to simply connect all three systems directly?

For one thing, your UPS may not operate unless it detects that incoming DC is in a certain volt range. PV panels might output 23V with light load even though they are rated for a 12V system.

The batteries are a source of stable voltage. Let them charge continuously from the PV panels as necessary (or as the panels provide). Then after they are charged to 14.2 V, any excess PV power automatically bypasses them and goes to the load.

 

[Revolutionist]

load attached to UPS system has separate wiring from utility load though it uses the neutral of utility but phase wiring is separate from utility so theirs no chance that ups supply might mix up with utility and return back towards distribution transformer in case of blackout.

The problem is that i daily have to turn off and on UPS AC supply manually (so that it can work in inverter mode ) in morning and evening respectively. Panels provides power to batteries (i have 2 batteries connected in series 24V DC system) and inverter take power from batteries and fetch the ac power to load in morning. And battery life mainly depends upon charging and discharging cycles, as they are charged and discharged by Panels and UPS simultaneously so its dramatically reduces their life from 3 years to 1 year or less. so to increase the battery life i want battery always to be topped up and only be used in case of blackouts. That's why i wanna make an automatic device which can sense and switch accordingly. i hope u will get my point.

i wanna make a device which sense the power or availability of these three sources (Panels, batteries, utility) and then provide power to load from 1 of the sources according to this priority 1st Panels 2nd utility and 3rd batteries (Panels>utility>batteries).

 

[BradtheRad]

Just to show how a basic setup might look...



The scope traces display a day's schedule. The upper three scope traces show the bias signals applied to the transistors.

This only shows the arrangement of N devices, and how they might switch three actions in your system. It shows how you need to apply the bias signal. (The red led shows that the PV panel is charging the battery, early in the day.)

A capacitor stands in for the battery.

You'll want to add devices such as the charge controller, voltage regulator, UPS, etc.

Does your UPS draw 100A or more? Then you'll need a very robust switching device, whether it's a transistor or mosfet or relay.

 

[betwixt]

load attached to UPS system has separate wiring from utility load though it uses the neutral of utility but phase wiring is separate from utility so theirs no chance that ups supply might mix up with utility and return back towards distribution transformer in case of blackout.

That would be illegal in almost every country and very dangerous. Suppose the Neutral wire broke and therefore your system detected power failure and switched to the inverter. You could potentially add your own voltage to the phase line, doubling the voltage across the break. You should break ALL incoming connections with an approved isolating switch when you use your own power generator.

Brian.

 

[Engineer Haseeb Nawaz]

I want to work on hybrid Inverter please provide me circuit diagram and related material thanks alot