  A revised Incremental Conductance (IncCond) maximum power point tracking
(MPPT) algorithm for PV generation systems is proposed in this paper. The
commonly adopted traditional IncCond method uses a constant step size for
voltage adjustment and is difficult to achieve both a good tracking performance
and quick elimination of the oscillations, especially under the dramatic
changes of the environment conditions. For the revised algorithm, the
incremental voltage change step size is adaptively adjusted based on the slope
of the power-voltage (P-V) curve. An accelerating factor and a decelerating
factor are further applied to adjust the voltage step change considering
whether the sign of the P-V curve slope remains the same or not in a subsequent
tracking step. In addition, the upper bound of the maximum voltage step change
is also updated considering the information of sign changes. The revised MPPT
algorithm can quickly track the maximum power points (MPPs) and remove the
oscillation of the actual operation points around the real MPPs. The
effectiveness of the revised algorithm is demonstrated using a simulation.
