Modeling of Lightning Transients in Photovoltaic Bracket Systems

The lightning transient calculation is carried out in this paper for photovoltaic (PV) bracket systems. The electrical parameters of the conducting branches and earthing electrodes are represented by resistances, capacitances, and inductances. A set of formulas are derived to evaluate the electrical parameters, which are appropriate for the complicated spatial locations of the conducting branches. On the basis of the electrical parameters, the equivalent circuits are constructed for the segmented branches and electrode units in a PV bracket system. By integrating all the equivalent circuits, a complete circuit model is built for the PV bracket system. The lightning transient responses can be obtained from the circuit model. In order to confirm the validity of the circuit model, experimental measurement is made with a reduced-scale PV bracket system and the measured results are compared with the calculated ones. Then, an actual PV bracket system is used as the numerical example. The lightning transient responses are calculated for typical locations of attachment points. The distribution characteristic of lightning transient responses is also explored in the PV bracket system.