Electrical power systems can be subjected to transient overvoltages from sources such as lightning strikes and switching surges. These events can severely damage your electrical assets, endanger personnel, and cause costly downtime. Even minor system failures can cascade into widespread outages, leading to significant financial losses and damage to your reputation. Insulation coordination studies reduce these risks by optimising insulation levels to meet safety and compliance standards.
By using tools like PSCAD and EMTP to simulate electrical stresses, electrical engineers can identify vulnerabilities and implement tailored solutions that enhance system resilience and extend the lifespan of your assets. This article outlines the key objectives, applications, and benefits of insulation coordination studies, highlighting how they can contribute to safer, more reliable power systems.
What is Insulation Coordination?
Insulation coordination is the process of designing and optimising power system insulation to withstand electrical stresses, such as transient overvoltages, protecting both equipment and personnel. It involves several critical steps:
- Insulation Selection: Choosing appropriate insulation materials based on voltage levels, environmental conditions, and operational requirements. These materials must balance performance and longevity for both routine operations and extreme events.
- Clearance and Creepage Design: Establishing appropriate physical distances between components to prevent flashovers and surface tracking. This step incorporates industry standards, environmental factors, and system configuration.
- Protective Device Placement: Strategically placing surge arresters and other protective devices to divert harmful surges away from key assets. This is informed by simulation data and system vulnerability assessments.
- System Simulation: Specialist software is used to create detailed transient models of potential overvoltages and transient events. This enables the testing of insulation designs under various stress scenarios.
These measures not only reduce the likelihood of equipment failures, service disruptions, and safety incidents but also ensure regulatory compliance and deliver long-term operational benefits. This comprehensive approach results in a more robust and reliable power system.
Key Benefits of Insulation Coordination Studies
Equipment Protection and Extended Lifespan
Insulation coordination prevents failures by ensuring that electrical assets such as transformers, switchgear, and cables are appropriately protected. Electromagnetic Transient (EMT) driven simulations help identify weak points and apply optimised insulation levels to minimise overvoltage exposure and reduce wear and tear, thereby extending the lifespan of critical components. Effective insulation also reduces maintenance needs by preventing cumulative stress that can degrade assets over time.
Enhanced Power System Safety
Effective insulation coordination reduces the risk of hazardous electrical events by ensuring proper clearances and surge protection. Simulating transient conditions with software such as PSCAD tests designs for worst-case scenarios, reducing the likelihood of an arc flash and flashovers. This approach creates safer environments for maintenance crews and operators by pre-emptively addressing potential fault points and ensuring that protective devices are correctly rated and positioned.
Improved Reliability
Insulation coordination improves system reliability by preventing failures that lead to unplanned downtime. Detailed EMT studies using PSCAD simulations model fault scenarios, lightning strikes, and switching surges, enabling precise adjustments to insulation levels and surge protection placement to ensure continuous operation. These simulations also help evaluate system responses to worst-case events and provide insights into mitigation strategies that prevent cascading failures across critical components.
Regulatory Compliance
Ensuring compliance with industry standards is a crucial outcome of insulation coordination studies. PSCAD-based studies align insulation performance with guidelines from international organisations such as:
- IEC 60071: Guidelines for insulation coordination in high-voltage systems.
- IEEE C62 Series: Standards for surge protection devices and insulation performance.
- IEC 60664: Recommendations for clearance and creepage distances in electrical systems.
- National Grid Codes: Regional frameworks specifying insulation requirements.
Meeting these standards and best practices helps you avoid penalties, supporting the implementation of consistent designs that prioritise operational safety and the future readiness of your power systems.
Applications of Insulation Coordination Studies
Insulation coordination studies have broad applications across different power system environments and upgrades:
Substation Upgrades and Modernisation
Updating ageing substations with improved insulation levels to address modern overvoltage challenges. This process involves evaluating new load requirements, refining the placement of protective devices, and conducting transient simulations to verify performance and ensure system resilience.
High-Voltage Direct Current (HVDC) Systems
Tailoring insulation solutions to meet the unique requirements of HVDC systems, particularly in interconnectors and offshore wind projects. These studies include modelling fast-pulse overvoltages and switching surges using simulation software tools to ensure stable and continuous operation.
Distributed Energy Resources (DER) Integration
Ensuring localised grids, microgrids, and renewable installations like rooftop solar and wind farms remain stable by addressing bidirectional power flows and sudden generation fluctuations through detailed simulations.
Data Centres and Critical Infrastructure
Designing robust overvoltage protection strategies to prevent downtime in critical environments such as data centres and hospitals, incorporating redundancy and fault-tolerant designs.
Battery Energy Storage Systems (BESS)
Addressing the fast-switching surges and high discharge events unique to BESS by accounting for inverter switching behaviours and sudden power shifts to ensure seamless integration.
EPS’s Insulation Coordination Expertise
At EPS, we provide tailored insulation coordination studies to meet the specific needs of your power system. Leveraging advanced PSCAD simulations, we can model transient overvoltage scenarios and identify vulnerabilities in your system. This enables us to design customised solutions that optimise system performance while protecting your valuable assets.
Notable Projects
Insulation Coordination for an onshore wind farm located in Scotland (132kV) as part of grid code compliance & connection studies project
Our experts conducted in-depth cable studies, assessing cable ratings, heating, temperature, short-circuit performance, and shield overvoltages. We developed precise models to evaluate MV and HV cable configurations under various scenarios.
What We’re Currently Working On:
- Transmission & Distribution (T&D) – 275kV substation located in Scotland
- Insulation coordination for a 500 MW Battery Energy Storage System (BESS) connected at 400kV.
Partner with EPS Today!
We undertake detailed analysis and reporting of your electrical network, guiding more resilient and future-proof power systems. Find out more about how our insulation coordination expertise can benefit your projects. Speak to us about your project requirements today.
