Performing Arc Flash Hazard Analysis (AFHA) on wind farms presents unusual challenges to electrical engineers performing the studies and to the wind farm personnel who must implement the AFHA results. The software used to do the Incident Energy (IE) calculations must be adapted to having literally hundreds of large generators in the system, and there are often regulatory and manufacturer limitations that make it difficult to make the changes necessary to protect turbine technicians from arc flash hazards.
This paper will identify the principle engineering issues in need of management and will specify the types of equipment changes that can be used to design Safety-into the wind farm system.
Before discussing this topic further, the reader must understand the following terms:
Collector System: The Collector system on a wind farm consists of the (usually) 34,500volt (34.5KV) conductors that receive the power produced by each generator and transmit it to the transmission substation.
Incident Energy (IE): The amount of energy impressed on a surface, at a given distance from the source, generated during an arc event. Incident energy is measured in joules per square centimeter or calories per square centimeter.
Nacelle: This is the housing that contains the generator and the gearbox that converts the Force of the wind to Rotational Kinetic Energy that drives the gearbox which in turn rotates the generator. A picture of a nacelle appears as Figure 1.
