A Novel Crossover Wiring of DC Cable for Photovoltaic System Against Lightning-Induced Overvoltage

Photovoltaic (PV) arrays are installed in wide-open areas, and they are vulnerable to indirect lightning strikes. The electronic devices in proximity may be damaged by the induced voltage caused by the impulse magnetic field across the dc cable loop for PV system. By compensating the magnetic flux, a novel crossover cable wiring is proposed in this article against lightning-induced overvoltage. Considering the electromagnetic coupling of PV bracket and metal frames, the magnetic field near PV array is computed, and the differential-mode-induced voltages in cables under different wirings are then compared. The influences of lightning striking points, mounting system structure, PV oblique angle and soil, etc., are discussed. The results indicate that the use of the proposed cable wiring scheme can reduce the induced voltage remarkably without any additional protective devices. The proposed crossover wiring scheme is easy to implement and cost-effective, which can provide guidance for cable wiring design of PV systems.