Is the double closed-loop control system a pi control loop of voltage outer loop and inner loop?

This control method is usually used in the charger circuit. The purpose is to achieve constant current charging while limiting the final charging voltage.

The realization method is to set two reference parameters, which are used to control current and voltage respectively.

At the initial stage of charging, due to the low output voltage, the voltage limit can not be reached. So there is only one control loop-current loop, the output current is controlled, and the working mode is constant current output.

At the end of charging, the output voltage reaches the voltage limit. At this time, the voltage loop starts to work, the output voltage is limited, and the current loop loses its function. The working mode is constant voltage output.