Maximum Power Point Tracking With Ripple Current Orientation for Photovoltaic Applications

Experimental tests reveal that the rippled current and voltage of a photovoltaic (PV) panel are always out of phase when the peak of the current is less than the current at the maximum power point (MPP), but begins to deviate once the current peak goes beyond the MPP. This paper proposes an efficient MPP tracking (MPPT) method by ripple current orientation based on the detected phase deviation of the PV voltage and current. By continuously detecting the phase difference, the PV panel can be operated at the MPP under constant atmosphere condition and can quickly move to the new MPP when the operating condition has been changed. A laboratory PV system with a microcontroller and a phase detection circuit is set up to verify the feasibility and effectiveness of the MPPT control strategy.