Protection of Power Plants Against Lightning and Overvoltage

Energy plants, besides containing many electrical and electronic devices, should be protected with special attention against lightning and overvoltage due to their exposure to lightning strikes. In wind power plants, solar power plants, hydroelectric power plants (HPPs), natural gas plants, thermal and coal power plants, 4-layer protection systems (internal lightning protection, external lightning protection, grounding, and equipotential bonding) should be installed to ensure continuous production and protect the entire plant area.

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Four-layer protection should be maintained for lightning and overvoltage protection in energy plants.

For external lightning protection in energy plants, one of the following methods should be selected depending on the plant structure, according to TS 62305 standard:

• Faraday Cage System
• IsFang Lightning Rod Systems
• Mesh Method
• Tension Wire Method
• Protection Angle Method
• Isolated External Lightning Protection Systems

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Isolated Down Conductor

For occupational safety in energy plants, isolated down conductors that can withstand 200 kA test impulses and isolate magnetic and thermal effects should be used. Lightning impulses flowing through bare conductors can negatively affect critical elements of energy plants.

Protection Against Internal Overvoltages

Energy plants frequently experience load shedding events and use circuit elements such as breakers and disconnectors. Therefore, internal overvoltages occur frequently. Fires in such plants generally result from incomplete protection against these sudden overvoltages. For full protection, auxiliary panels should be protected with Class C parafudrs and sensitive elements with Class D products.

Examples of Structures to Be Protected

• Transformer kiosks
• PLC, SCADA, and general automation systems
• Communication and data lines RS 232-485, Profibus, Ethernet, etc.
• Energy analyzers, sensors, CCTV, DVR
• Telephone communication systems
• Lighting systems protection
• Warning and alarm systems
• Relays