Maximum power point tracking method, photovoltaic system controller and photovoltaic system

摘要

Disclosed is a method (400) of tracking a maximum power point (MPP) of a PV (photovoltaic) system (100) comprising a circuit (120) including a controller (124) controlling a DC voltage - DC voltage converter (126) for converting an output current of the photovoltaic system, the controller further comprising a memory, the method comprising measuring (412) a first value of a photovoltaic system voltage at an initial maximum power point; storing said first value in said memory; periodically sampling (406) a power output level of said photovoltaic system, and upon detecting a change in said power output level exceeding a first threshold, reading the first value from the memory; and adjusting (410) a duty cycle of the DC voltage - DC voltage converter until the circuit voltage matches said first value; the method further comprising fine-tuning (414) the duty cycle of the DC voltage - DC voltage converter to a further maximum power point following detecting a change in said power output level exceeding a first threshold. Such a method is capable of extracting the maximum power out of a PV system. A PV system controller implementing this method and a PV system including such a controller are also disclosed.