Lightning Protection in PE Power Exam
Wasim Asghar 
May 25, 2023Welcome to my blog on Lightning Protection in PE Power Exam! If you’re preparing for the PE Power Exam, you already know how crucial it is to understand the ins and outs of electrical systems. Lightning protection is a vital component of any electrical system, and it’s an area that requires particular attention during the exam.
As you know, lightning is a natural phenomenon that can cause severe damage to electrical equipment, structures, and even human life. Understanding how to protect against lightning strikes is crucial, especially in high-risk infrastructures such as power plants, transmission lines, and power substations.
This blog will dive deep into lightning protection, exploring the principles and methodologies used to safeguard electrical systems against lightning strikes. We’ll discuss the science behind lightning, the different types of lightning protection systems, and the design and installation considerations you’ll need to know for the PE Power Exam.
By the end of this blog, you’ll have a solid understanding of lightning protection in the PE power exam, and you will find yourself ready to tackle any questions related to this topic on the PE Power Exam. So, buckle up, and let’s get started!
Importance of Lightning Protection in the PE Power Exam
Recently, lightning strikes caused a power outage in a Texas power plant in 2021, leading to statewide blackouts. This incident stresses the importance of lightning protection in high-risk and commercial infrastructures, making it a critical topic from the standpoint of the exam.
But when is lightning protection required? To picture the most practical use case of lightning protection systems, we have compiled some conditions that make it mandatory for PE aspirants to prepare for the Lightning Protection in the PE Power Exam and ensure success in the test & career.
- Understanding the principles and methods of lightning protection is essential for ensuring the safety and reliability of high-risk electrical and power systems.
- In the PE Power Exam, questions related to lightning protection can cover various topics, from design considerations to installation practices.
- A thorough understanding of lightning protection can help power engineers design and implement effective protection systems that mitigate the risk of lightning strikes.
- Knowledge of lightning protection can also demonstrate a power engineer’s expertise and commitment to safety, which can be valuable in professional settings and job opportunities.
Overview of lightning and how it is generated
Lightning is a fascinating and powerful natural phenomenon caused by an electrical discharge between storm clouds and the ground. It’s hard to imagine, but most lightning occurs within the clouds themselves!
The blog on Lightning by National Geographic states that there are different lightning flashes. Sheet lightning lights up entire cloud bases and bolts that appear as bead, ribbon, or rocket lightning. During a storm, the colliding particles of rain, ice, or snow inside storm clouds create an imbalance between the clouds and the ground.
This often negatively charges the lower parts of the storm clouds while the objects on the ground, like steeples, trees, and even the Earth itself, become positively charged.
Nature seeks to remedy this imbalance by passing current between the two charges, resulting in lightning bolts over five times hotter than the sun’s surface! This intense heat causes the surrounding air to rapidly expand and vibrate, which creates the thunder we hear after seeing a lightning flash.
Cloud-to-ground lightning bolts are more common, with about 100 strikes hitting Earth’s surface every second! Each bolt can contain up to one billion volts of electricity.
To put that into perspective, the average home in the United States uses about 120 volts of electricity. So one lightning bolt contains the power of millions of homes combined! No wonder lightning can be dangerous, causing fires, power outages, and even fatalities.
Despite its power and danger, lightning remains a fascinating force of nature that reminds us of the incredible energy surrounding us.
Lightning Protection Design Principles
Before moving further to the more technical depth of the topic, let’s discuss some key areas and lightning protection requirements necessary to ensure lightning protection.
Risk Assessment for Lightning Strikes
The first step in designing a lightning protection system is to assess the risk of a lightning strike. This assessment should consider the system’s location, the frequency of lightning strikes in the area, and the potential consequences of a lightning strike.
Lightning Protection Zones and Their Characteristics
Once the risk assessment is complete, the system should be designed based on the principle of lightning protection zones. These zones include the protection zone, the equipotential bonding zone, and the separation distance zone. The protection zone is the area of the structure that needs to be protected from a direct lightning strike.
In contrast, the equipotential bonding zone and the separation distance zone are designed to protect against the indirect effects of lightning strikes.
Surge Protection and Grounding Systems
Surge protection devices or SPDs (three different types discussed later in the blog) are essential to lightning protection systems. SPDs protect against overvoltages that can damage electrical infrastructure and equipment.
Grounding systems are also critical, providing a low-resistance path for lightning currents to flow to the ground. Proper grounding helps to prevent damage to equipment and ensures the safety of personnel.
Earthing and Bonding
Earthing and bonding are crucial components of lightning protection systems.Earthing provides a low-resistance path for lightning currents to flow to the ground.
At the same time, bonding ensures that all metallic components in the electrical system are at the same potential to prevent dangerous differences in potential. Proper earthing and bonding can help to prevent equipment damage and ensure personnel safety.
Lightning Protection in Power Systems
Let’s discuss the essential aspects, techniques, and devices used in Power generation, transmission, and distribution systems.
Importance of lightning protection in power systems
According to a Carbon Brief study, it was found that lightning strikes in the US are expected to increase by 12% for every degree of temperature rise. With the increasing threat of climate change, we can expect to see even more lightning strikes in the coming years.
This finding has significant implications for power systems. Lightning strikes are already a leading cause of damage and downtime for power stations in the US, with the potential to cause equipment damage, power outages, and even fires.
With the predicted increase in lightning strikes, the importance of adequate lightning protection in power systems cannot be overstated.
Power engineers must ensure that lightning protection systems are designed and implemented effectively to minimize the risk of lightning strikes causing damage or disruption to power systems.
In addition, the growing threat of lightning strikes due to climate change highlights the need for ongoing research and development of lightning protection technologies to keep pace with the changing risk landscape.
Design of lightning protection systems in power systems
When it comes to lightning protection in power systems, five key elements make up a comprehensive lightning protection system. According to the lightning protection codes and standard guidelines, the lightning protection systems possess the following key elements.
- Roof network,
- Down conductors,
- Equipotential bonding,
- Grounding system,
- Surge protection devices (SDPs) & Communication lines.
Each of these elements plays a critical role in protecting power systems from the damaging effects of lightning strikes. The roof network provides a network of conductors that safely channels lightning strikes away from the building, while down conductors and equipotential bonding help to ensure that the lightning current is dispersed safely into the ground.
A grounding system is essential for providing a low-impedance path for lightning current, while surge suppression devices protect sensitive equipment from power surges caused by lightning strikes.
Despite these elements’ importance, lightning protection systems’ effectiveness can vary widely depending on their design, installation, and maintenance. Some standard lightning protection techniques in power systems include lightning rods, surge arresters, and grounding systems.
It is essential to ensure that these techniques are implemented correctly to provide adequate protection against lightning strikes, safeguard sensitive electrical equipment, prevent downtime and equipment damage caused by lightning strikes, & ensuring the safety of personnel working in and around power systems.
Surge protection devices (SPDs) and their applications
Being a power system or electrical engineer, you must recognize how damaging a power surge or a lightning strike can be to your electrical infrastructure. The next step is to find an effective solution to this challenge posed by inevitable and powerful natural phenomena.
That’s where the Surge Protection Device (SPD) comes in. The SPD is a component of an electrical protection system, and it’s designed to protect your devices from overvoltages caused by lightning or other electrical events. It’s like a safety valve for your system, allowing energy to be redirected safely away from your devices.
The SPD is connected in parallel to the power supply circuit of the loads it’s meant to protect. It can be used at all levels of the power supply network, and it’s the most commonly used and efficient type of overvoltage protection.
The SPD’s main job is to limit transient overvoltages of atmospheric origin and divert current waves to the earth to limit the amplitude of this overvoltage to a value that’s not hazardous for the electrical installation and electric switchgear and controlgear.
The SPD’s ability to eliminate overvoltages in common and differential modes makes it so effective. It can protect your devices from overvoltages between phase and neutral or earth and between phase and neutral.
lightning protection standards, there are three main types of SPDs, each with a specific purpose and use a case in power distribution, power generation, and power transmission systems:
| SPD Type | Purpose | Use Case |
| Type 1 (or Class I) | Protects against direct lightning strikes | Used in high-risk areas such as power transmission systems, substations, and extensive industrial facilities. |
| Type 2 (or Class II) | Protects against overvoltages caused by indirect lightning strikes and switching operations | Used in low- to medium-risk areas such as power distribution systems and commercial buildings. |
| Type 3 (or Class III) | Protects against residual overvoltages and voltage spikes | Used in low-risk areas such as residential buildings. |
*By selecting the appropriate type of SPD for your specific use case, you can protect your electrical devices and systems against damage and downtime caused by lightning strikes.
Lightening Protection in Different Power Systems – Generation, Distribution, & Transmission
Power distribution, power generation, and power transmission systems are three distinct components of the electrical power grid. Each has its unique characteristics and challenges when it comes to lightning protection.
These topics also hold utmost importance concerning lightening protection in PE power exam preparation.
Lightening Protection in Power Distribution Systems
Power distribution systems deliver electricity from the distribution substation to end users, such as homes and businesses. These systems typically operate at lower voltages and involve using transformers and other equipment to step down the voltage to safe levels for consumer use.
Lightning protection in power distribution systems is focused on protecting the power lines and associated equipment from lightning strikes, using techniques such as grounding and installing surge protection devices.
Lightening Protection in Power Generation Systems
Power generation systems produce electricity distributed through the power grid. These systems typically involve large generators and transformers, which are at higher risk of damage from lightning strikes due to their size and complexity.
Lightning protection in power generation systems may involve installing lightning protection systems specifically designed to protect the more significant components used in these systems.
Lightening Protection in Power Generation Systems
Power transmission systems move electricity from the power generation facilities to the distribution substations. These systems typically operate at higher voltages than power distribution systems and involve long-distance power lines and associated equipment such as transformers and switchgear.
Lightning protection in power transmission systems is focused on protecting these high-voltage power lines and associated equipment from lightning strikes, using techniques such as shielding and installing surge protection devices.
*For more clarity and use cases of respective SDPs for each system concerning the intensity of lightning threat and sensitivity, consult the table above.
Conclusion
Apart from preparing and practicing the topic of lightning protection in the PE power exam, understanding lightning protection is a critical aspect of safeguarding power distribution systems. Ongoing research and development are essential to keep up with the evolving risks of lightning strikes.
Using surge protection devices and advanced grounding systems can help mitigate the impact of lightning strikes, reduce equipment damage, and prevent power outages.
For professionals in the power engineering field, such as those taking the PE power exam, understanding the concept and principles of lightning protection in PE power exam preparation is essential to ensure short and long-term success.
Furthermore, as technology and weather patterns continue to evolve at a skyrocketing pace, staying up to date on lightning protection techniques will remain an essential topic for the power industry.
For a more in-depth study and consultation for your PE power exam preparation, feel free to connect with Study for FE – your go-to online place for all queries concerning PE exam preparation and guidance.
Licensed Professional Engineer in Texas (PE), Florida (PE) and Ontario (P. Eng) with consulting experience in design, commissioning and plant engineering for clients in Energy, Mining and Infrastructure.