| 摘要 |
<p>The output of a photovoltaic array 10 subject to varying external influences is adjusted by altering at least one operating parameter, for instance the pulse-skipping parameter NSKIP of a DC-DC converter 20. The method includes the following steps:
(a) referring to a table (50) giving values of the operating parameter NSKIP in relation to an index (idx), of the array from which the operating parameter corresponding to the maximum-power point under different external influences is to be determined;
(b) if the table contains an entry for the current index value, using that entry to establish the operating parameter;
(c) if the table does not contain an entry, carrying out a recursive procedure to establish the value of the operating parameter appropriate for the instantaneous maximum power point MPP;
(d) storing the parameter value corresponding to this MPP in the table; and
(e) repeating steps (a) to (d) at intervals. The index corresponds to the short-circuit current I SC of the array 10, which can be measured by applying a reverse voltage to it; this eliminates inaccuracies due to the voltage drop across the internal diodes 14 of the array. From time to time the recursive procedure is carried out anyway, to update the table.</p> |
