Leveraging Simulation to Solve Power System Design Challenges: Corona and HVDC Cable Fields

<p>In the world of power systems, direct measurement—whether in the lab or out in the field—has long been considered the ultimate source of truth. Yet every measurement method comes with its own set of limitations. Simulation steps in to break through these barriers, accelerating design cycles, cutting costs, and enabling analysis of scenarios that are impractical to measure directly. This content explores two compelling examples from the industry: first, the challenge of validating corona performance for high-voltage transmission line hardware under realistic three-phase conditions; and second, the subtle but important electromagnetic effects around submarine HVDC cables caused by ocean currents interacting with static magnetic fields.</p> <h2 id="q1">Why is corona-free performance critical for high-voltage transmission line hardware, especially at 500 kV and above?</h2> <p>Corona discharges occur when the electric field around a conductor exceeds the breakdown strength of air, leading to ionization, power loss, audible noise, and radio interference. For transmission lines operating at 500 kV, 765 kV, or even higher voltages, even minor hardware irregularities can trigger corona. Ensuring that insulator hardware remains corona-free is essential for reliable operation, minimizing energy waste, and meeting environmental noise regulations. Hardware that performs well under controlled conditions may behave differently in the field, so rigorous testing is a must.</p><figure style="margin:20px 0"><img src="https://assets.rbl.ms/27157944/origin.png" alt="Leveraging Simulation to Solve Power System Design Challenges: Corona and HVDC Cable Fields" style="width:100%;height:auto;border-radius:8px" loading="lazy"><figcaption style="font-size:12px;color:#666;margin-top:5px">Source: spectrum.ieee.org</figcaption></figure> <h2 id="q2">What are the main limitations of laboratory corona testing?</h2> <p>Standard laboratory setups typically use a single-phase mockup to evaluate hardware corona performance. While convenient, this approach cannot fully replicate the three-phase electromagnetic environment of actual transmission lines. Physical space constraints in the lab force engineers to test only a partial configuration, making it difficult to establish equivalence between the simplified test and real-world conditions. Additionally, factors such as weather, altitude, and adjacent phase interactions are hard to recreate in a confined space. These limitations can lead to designs that pass lab tests but underperform in the field.</p> <h2 id="q3">How can modern simulation overcome these corona testing challenges?</h2> <p>Simulation tools allow engineers to model the full three-phase environment accurately, even when only single-phase data is available from the lab. By creating a digital twin of the transmission line, simulations can account for phase spacing, conductor sag, electric field gradients, and environmental variables. This bridges the gap between laboratory and real-world performance, enabling engineers to predict corona onset and optimize hardware geometry without building costly full-scale prototypes. The result is faster iterations, lower design costs, and higher confidence that hardware will perform as intended once deployed.</p> <h2 id="q4">What is the common misconception about electromagnetic fields from HVDC submarine cables?</h2> <p>Many assume that HVDC submarine cables are electromagnetically inert outside their insulation. Because direct current produces a static magnetic field—not a time-varying one—it does not induce voltages or currents in nearby objects under stationary conditions. This leads to the belief that the cable poses no external electric field risk. However, this view overlooks the relative motion between the cable's static magnetic field and the surrounding seawater, which is constantly moving due to ocean currents.</p><figure style="margin:20px 0"><img src="https://assets-ext.bizzabo.com/bizzaboprod/image/upload/q_auto,f_auto,c_scale,c_crop,g_custom/v1771409603/wbuvhin8ogbipururkwz" alt="Leveraging Simulation to Solve Power System Design Challenges: Corona and HVDC Cable Fields" style="width:100%;height:auto;border-radius:8px" loading="lazy"><figcaption style="font-size:12px;color:#666;margin-top:5px">Source: spectrum.ieee.org</figcaption></figure> <h2 id="q5">How do ocean currents create induced electric fields around HVDC cables?</h2> <p>Faraday's law states that a changing magnetic flux induces an electric field. Even with a static magnetic field, the relative motion between the conductor and a conductive medium like seawater satisfies the requirement for flux change. As ocean currents flow through the static magnetic field of an HVDC cable, they experience a motional EMF, producing localized electric fields in the water. These fields are weak but fall within the detection range of certain aquatic species, such as sharks and rays, which use electric fields for navigation and hunting. Simulation reveals that these fields exist and should be considered in environmental impact assessments.</p> <h2 id="q6">Why is simulation essential for studying these induced fields when direct measurement is not feasible?</h2> <p>Measuring induced electric fields around an operational submarine cable in deep water is extremely challenging and expensive. The fields are small, vary with tide and current, and require specialized sensors. Simulation provides a practical alternative, allowing engineers to model the cable geometry, magnetic field distribution, and ocean current profiles at any location and time. It can assess potential impacts on marine life before installation, support regulatory approvals, and guide cable placement to minimize ecological disturbance. Without simulation, such analysis would be nearly impossible, leaving critical environmental effects undetected.</p> <p>These examples showcase how modern simulation not only saves time and money but also uncovers phenomena that would otherwise remain hidden. For deeper insights, explore the original webinar content on <a href="#q1">corona testing</a> and <a href="#q5">HVDC cable fields</a>.</p>