Design and analysis of a microprocessor-controlled peak-power-tracking system [for solar cell arrays]

Stability and dynamics of a series configuration peak-power tracking (PPT) system are analyzed. The operating modes of the system, as well as mode transitions, are investigated based on qualitative graphical representations of dc load lines at various interfaces of the system. Analysis of multiloop control in the PPT mode is discussed. This includes the design of the inner voltage loop and analysis of the closed-loop system stability around the peak-power point. For an optimum dynamic performance and stability, design parameters of the inner voltage loop and the outer PPT loop are identified. Experimental verifications, supported by simulation results, are performed.