Analog Fixed Maximum Power Point control for a PWM step-down converter for water pumping installations

This paper describes a fixed maximum power point analog control used in a step-down pulse width modulated power converter. The DC/DC converter drives a DC motor used in small water pumping installations, without any electric storage device. The power supply is provided by PV panels working around their maximum power point, with a fixed operating voltage value. The control circuit implementation is not only simple and cheap, but also robust and reliable. System protections and adjustments are also proposed. Simulations and hardware are reported in the paper for a 150 W water pumping application system. The proposed optimal power point fix voltage control system is analyzed in comparison to other complex controls.