air insulated and gas insulated substation design blog post

The beating heart of any reliable, robust electrical grid system lies in its substation design. A substation might not be the most visible aspect of a power distribution network, but it's undeniably one of the most critical. Its efficiency, safety features, and resilience determine the overall stability and reliability of the electrical supply to infrastructure, industries, and homes alike. Any failure in this crucial component can lead to widespread power outages, significant economic losses, and potentially hazardous situations. Thus, the importance of investing in high-quality substation design and maintenance cannot be overstated—it's a foundational pillar for a secure, dependable energy future. 

In the United States and around the globe, there is a need for electrical grid upgrades to meet the needs of a growing population and severe weather events. High-voltage substations, which serve as crucial points in the intricate power transmission setup, are vital in meeting increasing demands securely and dependably. There are a variety of types of switchgear designed for high-voltage substations that offer the flexibility to provide customized solutions, including:

  • Air-Insulated Substation (AIS): cost-effective, suitable for outdoor locations, low maintenance 
  • Gas-Insulated Substation (GIS): compact, reliable, safer, minimal environmental impact, suitable for densely populated urban areas
  • Hybrid Substation: flexible, offers a balance between cost effectiveness and space optimization

At the time of this article, the gas-insulated substation market is projected to grow significantly over the next two years, and potentially by more than 10% by 2030. This is due primarily to the growing need for environmentally friendly solutions across a variety of sectors, as well as the smaller footprint. Our team at RTP is currently designing modifications to an EHV GIS substation located in the downtown area of a major city that provides power to a large number of residents, businesses, and institutions. While this 500,000 volt substation is a powerful and critical source of energy, the average passerby will not even realize that they are walking past a substation.

The Rise of Gas Insulated Switchgear Stations 

As our infrastructure ages and our population increases, the need for modernizing our grid could not be greater. Challenges such as increased demand, the need for renewable energy integration, and the incessant pull for efficiency have made Gas Insulated switchgear substations the preferred choice to define the future landscape of electricity distribution. 

The key to GIS lies in its design, representing a quantum leap in substation technology. With the ability to compress massive power distribution infrastructure into a fraction of the space needed by conventional air insulated substations (AIS), GIS is a game-changer in efficiency and environmental impact.

The GIS approach offers safety and environmental advantages that can't be overlooked. Since the GIS system is totally encapsulated and insulated from the external environment, it is impervious to particle or mist pollution, making it a preferred choice for densely populated urban areas and other locations where land is a premium. Its compact design and ability to withstand high voltages make it a preferred choice for urban areas, where space is limited.

The cost of installation might be higher initially, due to the sophisticated design and materials involved, but the long-term economic benefits of GIS, including reduced land usage and operational costs, often outweigh the upfront expense. The reduced environmental footprint is a welcome bonus in today's world, where sustainable practices are increasingly becoming a priority.

Mitigating Arc Flash Hazards in Substations

In today’s rapidly advancing technological landscape, ensuring the safety and efficiency of industrial plants can’t be overstated. One of the critical challenges in substation design is effectively mitigating the dangers posed by arc flashes – a sudden and potent discharge of electrical energy that occurs when a significant fault condition or short circuit flows through the air from one conductor to another, or to ground. These incidents are not only hazardous to the electrical equipment within substations but also pose a deadly risk to personnel working within or near substation environments.

According to the National Fire Protection Association (NFPA), there are over 30,000 arc flash incidents in the United States every year, leading to severe injuries and even fatalities. The intense heat from an arc flash can reach temperatures as high as 35,000 degrees Fahrenheit, over three times the surface temperature of the sun, causing catastrophic burns and igniting flammable clothing instantly. Beyond the immediate physical danger, arc flashes can also result in costly downtime for facilities, loss of equipment, and legal liabilities for companies.

Well-designed substations are crucial in minimizing the risk of arc flashes, along with in depth arc flash studies and strictly adhering to OSHA standards. According to Substation Safety’s 6-point plan for arc flash OSHA compliance, an in-depth safety program must be provided to employees, along with an accurate analysis of the degree of arc flash hazard presented on the substation, and training and equipment suitable for the hazard present.

By incorporating advanced protective technologies, spatial layouts that reduce the likelihood of fault conditions, and isolation features that help contain incidents should they occur, a thoughtfully engineered substation can significantly decrease the chances of such dangerous events. In essence, through meticulous design and adherence to the highest safety standards, substations play an indispensable role in safeguarding lives and maintaining continuous, reliable power distribution in industrial plants.

The Market Matters: Substation Design Across Industries

It is vital to understand that successful substation design is not a one-size-fits-all affair. Industries such as the steel, chemical, oil & gas, and general manufacturing sectors each have their specific needs and regulations. A substation designed for a steel plant might differ vastly from one serving an oil refinery, both in terms of the equipment used and the safety standards imposed.

At RTP, we take a thorough substation design approach to cater to various needs, encompassing GIS, AIS, and hybrid configurations. Our process covers defining equipment specs, crafting clear diagrams, prioritizing safety measures, and optimizing functionality. We ensure power distribution and integrate security features like the Kirk Key System. Our designs prioritize stability and accuracy, providing reliable solutions for our clients’ needs. 

Our vast portfolio of over 50 completed substation projects includes:

  • 69 KV Switchyard Substation for the Bauxite Mine Project in Toll Gate, Jamaica, owned by ALCOA Minerals of Jamaica. The scope involved protective device setting and relay coordination studies for the utility tie-line, as well as a ground grid analysis using ETAP Powerstation software.
  • 100 KV Transformer/Thyristor Rectifier Substation for the Zinc Facility Project in Mooresboro, North Carolina, owned by Horsehead Corporation. RTP conducted ground grid analysis to meet ABB requirements and ensure the design met standards.
  • 100 KV Harmonic Filter Substation for the same Zinc Facility Project, involving protective device setting and relay coordination studies for various equipment, along with ground grid analysis.
  • SVC PLUS Substation for the Steel Melt Shop Project in Calvert, Alabama, owned by Thyssen Krupp Corporation.
  • 161 KV Aluminum Potline Rectifier Substation for the Aluminum Facility Project in New Madrid, Missouri, owned by Noranda Aluminum, Inc. This included installation engineering for various equipment such as thyristor bridges, rectifier transformers, harmonic filters, and transformers.

RTP has also untaken projects for clients, including MEPPI, Dominion Power, Hitachi Energy, ConEd. Caribbean Utility Company, First Energy, Ohio Star Forge, Jamalco, ALCOA, Noranda, and USS, encompassing various voltage levels and configurations across different locations.We pride ourselves on the ability to deliver substation designs that not only meet industry-specific requirements but also surpass client expectations in terms of reliability and long-term performance. Whether it's an industrial facility or a city's backbone power grid, our solutions are tailored to safeguard against downtime and deliver power uninterrupted.