A maximum power point tracking control method suitable for compact wind power generators

This paper describes a maximum power point tracking (MPPT) control method for propeller type compact wind power generators with passive self-pitch controlled blades that quickly makes the output current and voltage converge on the maximum power point based on wind speeds detected from an anemometer. The voltage and current output from these wind power generators change variously with wind speeds at locations such roofs of building which are suited to these generators. Transient characteristics of the voltage output from compact wind power generators have two modes because of the self-pitch controlled blades: mode I in which the output voltage hardly increases and mode Π in which it rapidly increases. Thus, in order to acquire the generated power effectively, however wind speeds may change, a method to perform the MPPT control while searching for mode II is needed. Thus, by judging the mode from the change of the sign of the time differential of the voltage deviation between sampling times, the MPPT control method is proposed here that makes the output current converge on the maximum point using relationships between the maximum power and optimal current which give the maximum power and the wind speed. Effectiveness of the proposed MPPT control method is verified through simulations and experiments using a wind tunnel apparatus.