Difficulty in understanding charge controller for solar and wind energy

Question

I am having difficulty in understanding one control box which is used to charge the battery using solar and wind energy as well as power the load at the same time. I have attached the picture below

I understand the part of the wind turbine but what I don't understand is the part where it shows the positive terminal of solar panel, battery and load should be connected together. How can this work? since the battery is charging (connected to solar panel) as well as discharging (connected to load) at the same time?

In my mind I was thinking the controller would be more like this the following, , here you have separate connection point for each components which make sense to me but in my previous picture I don't understand. Can any one answer this for me.

Answer 1

Very crudely it will look like this:

^{simulate this circuit – Schematic created using CircuitLab}

How it works

• D1 to 6 rectify the three-phase current from the turbine to feed the "DC bus". If the turbine is running or voltage output from it is low D1 to D6 will be reverse biased and the battery can't discharge through the turbine windings.
• The panel also feeds power into the DC bus. I've shown D7 to prevent discharging the battery through the panel. In practice it will be more complicated than that if the system optimises the power transfer from the panel.
• SW1 and 2 can be switched by the controller to regulate voltage or power to the load and the battery charging current. Again, this is highly simplified but you would expect the controller to prioritise the load if input power is low and charge the battery when possible. When input power is lower than the load the battery will supply power. When battery voltage drops to a preset low limit the load should be automatically disconnected.

The same design could be achieved using your terminal arrangement and connecting all the '+' terminals internally. They saved two terminals doing it this way!