Lightning : solar energy and wind energy characterized as new energy, play an every important role in the development of energy and power industry . unfortunately the fan of wind system and the panel in solar system are easily attacked by the lightning.those devices of system will be damaged by the ground attack by the lightning strike directly or indirectly .
Faulty Arc : there are some reasons such as joint loosening, bad connection , dampness wire, and rupture of insulation layer , those of all can create the faulty arc .
Harmonic and three phase unbalance：Iron core with ferromagnetic saturation characteristics such as transformer ,and power electronic components based on the switching power supply equipment such as inverter, existed in the system of new energy . so that there are a various of problems caused by harmonic and three phase unbalance.
Problem :
1 Increasing the loss of transmission circuit :
When Frequency of harmonic is in line with the resonance point or place thereof, voltage on the transmission circuit increasing a lot to disrupt the insulation layer .
2 Increasing the loss of transformer:
Loss of transformer and overheat are the mainly reason for the fire risk.
3 Decreasing the reliability of system operation :
Harmonic makes the relay device and auto-devices malfunction, reliability and action selectivity to system failure.
4 Increasing the loss of motor
The additional loss of motor affects the efficiency of motor working and overheat.
5 Affect running of measure, control instrument and communication system
For Weak current equipment such as computer network , communication units, harmonic in system of energy supply creates interference through electromagnetic and electrostatic coupling with system.