Key Takeaways
- Simulation can help overcome the limitations of laboratory or in-field measurements in power system design.
- Transmission hardware corona performance and HVDC submarine cable EM fields are critical aspects of power system design.
- Simulation can speed up the design process, reduce design costs, and assess situations that are often not feasible to measure directly.
- The first case discussed in the presentation involves transmission hardware corona performance.
- The second case involves HVDC submarine cable EM fields.
Simulation in Power System Design
In the power system industry, laboratory or in-field measurements are often considered the gold standard for certain aspects of power system design. However, measurement approaches always have limitations. Simulation can help overcome some of these limitations, including speeding up the design process, reducing design costs, and assessing situations that are often not feasible to measure directly.
The accuracy of simulation results depends on the complexity of the model and the available computational resources. A more complex model requires more computational resources, which can increase the simulation time.
Real-world testing of high-voltage systems comes with logistical and financial burdens. Setting up full-scale test environments for transmission lines or subsea cables demands large tracts of land, specialized equipment, and safety protocols that limit access and flexibility. Field measurements are also constrained by environmental conditions—wind, humidity, and ambient electromagnetic noise can distort readings. These variables make repeatable, controlled testing difficult. Simulation sidesteps many of these issues by offering a controlled digital environment where parameters can be adjusted with precision.
Developers can run hundreds of design iterations in days, testing configurations that would take months or years to validate physically. A design tweak—changing conductor spacing or modifying insulation thickness—can be modeled and evaluated in hours. This rapid feedback loop lets engineers explore edge cases: extreme weather, material fatigue, unexpected load conditions. These scenarios might never be replicated in a lab but can be simulated with high fidelity.
Still, simulation isn’t a replacement for measurement. It’s a complement. Models must be validated against real data to ensure accuracy. Early in a project, a hybrid approach is common: basic models are tuned using limited field data, then scaled to predict performance under untested conditions. The goal isn’t to eliminate physical testing but to reduce its scope and cost by focusing only on the most critical validation points.
Transmission Hardware Corona Performance
The first case discussed in the presentation involves transmission hardware corona performance. Corona discharge is a phenomenon that occurs when a high-voltage transmission line is subjected to a voltage gradient that is greater than the breakdown voltage of the surrounding air.
The simulation results show that corona discharge can have a significant impact on the transmission line’s performance.
Corona forms when the electric field near a conductor exceeds about 3 kV/mm, ionizing the air and creating a visible glow, audible noise, and energy loss. This effect becomes more pronounced at higher altitudes where air density is lower, reducing the dielectric strength of the surrounding atmosphere. Conductors with sharp edges or rough surfaces are especially prone, as electric fields concentrate at points of high curvature.
Engineers have long battled corona in transmission design. In the 1950s, as utilities began deploying 345 kV and higher systems, corona-related radio interference became a public concern. Early mitigation strategies included increasing conductor diameter and using bundled conductors—multiple wires spaced apart to distribute the electric field. These solutions worked but added weight and cost. Simulation now allows designers to model corona onset with greater precision, predicting where discharges are likely and optimizing hardware geometry before physical prototypes are built.
Modern simulation tools can map electric field gradients along an entire span of transmission hardware, accounting for insulators, fittings, and support structures. This level of detail helps identify “hot spots” where corona might initiate, even in complex junctions like dead-ends or jumper connections. By adjusting component shapes or materials in the model, engineers can reduce field intensity below the ionization threshold.
Corona Discharge Characteristics
- Corona discharge can lead to power loss and overheating of the transmission line.
- Corona discharge can also lead to the degradation of the insulation of the transmission line.
Power loss from corona is usually small under fair weather—typically less than 1 kW per mile on well-designed lines—but can spike during rain or fog when water droplets distort the electric field. While this might seem negligible on a system-wide scale, cumulative losses across thousands of miles of line can affect efficiency, especially in long-distance transmission corridors.
More concerning is the long-term impact on insulation and hardware. Corona produces ozone and nitrogen oxides, both of which attack polymer-based insulation materials. Over time, this chemical degradation weakens insulators, increasing the risk of flashover. Metal components near discharge zones can also suffer from pitting and erosion, compromising mechanical integrity. These effects are hard to detect in early field testing but can be projected in simulation by modeling chemical exposure over time.
Acoustic noise from corona is another issue, particularly near residential areas. The crackling or hissing sound can trigger public complaints, leading to regulatory scrutiny. Simulations can predict sound levels at ground level based on conductor configuration and weather, helping utilities avoid noise-related delays during permitting.
HVDC Submarine Cable EM Fields
The second case discussed in the presentation involves HVDC submarine cable EM fields. HVDC submarine cables are used for the transmission of electrical power over long distances.
The simulation results show that the EM fields generated by the HVDC submarine cable can have a significant impact on the surrounding environment.
Unlike HVAC systems, HVDC cables produce static electric and magnetic fields. The magnetic field, in particular, persists as long as current flows, creating a continuous field around the cable. While the field strength drops rapidly with distance, it can still interact with conductive structures on the seabed—pipelines, communication cables, even shipwrecks. These interactions can induce currents, leading to accelerated corrosion or interference with instrumentation.
Marine ecosystems are also a concern. Some species, like sharks and rays, are electroreceptive and may detect even weak fields. While there’s no conclusive evidence of large-scale harm, regulatory agencies often require environmental impact assessments before cable deployment. Simulation allows developers to model field dispersion under different burial depths, seabed compositions, and current loads, helping to minimize ecological disruption.
EM field modeling is especially valuable during route planning. A proposed cable path might need to cross existing infrastructure. Simulating the interaction helps avoid conflicts—say, a new HVDC line inducing currents in an old oil pipeline that could speed up corrosion. These risks can’t be easily tested in the field but are predictable through electromagnetic modeling.
EM Field Characteristics
- The EM fields generated by the HVDC submarine cable can lead to the degradation of the insulation of the surrounding environment.
- The EM fields can also lead to the heating of the surrounding environment.
Heating from EM fields is generally minor in HVDC systems, but in high-current applications or poorly conductive sediments, localized temperature rises can occur. Warm sediment alters microbial activity and may affect benthic communities. Simulation can estimate thermal plumes based on cable load and thermal resistivity of the seabed, informing burial depth and spacing requirements.
Insulation degradation is a slower process. Direct current stress, combined with mechanical pressure and saltwater exposure, can lead to space charge accumulation in cable insulation. Over decades, this can reduce dielectric strength and increase failure risk. Simulations can project space charge distribution over time, helping manufacturers refine insulation materials and layer thicknesses.
What This Means For You
The presentation highlights the importance of simulation in the power system industry. Simulation can help overcome the limitations of laboratory or in-field measurements, and it can speed up the design process, reduce design costs, and assess situations that are often not feasible to measure directly.
For developers and builders, the presentation shows that simulation can be a valuable tool in the design and development of transmission hardware and HVDC submarine cables.
The simulation results can help identify potential issues and optimize the design of the transmission hardware and HVDC submarine cables.
Consider a startup developing a new transmission tower design for offshore wind interconnections. Physical testing of full-scale prototypes in salt spray chambers is expensive and slow. Using simulation, the team can model corona performance across different weather conditions, tweak hardware geometry to minimize discharges, and validate the design before committing to fabrication. This approach reduces R&D costs and accelerates time to market.
For a utility planning a 500 kV submarine link between two islands, EM field simulation is critical during permitting. Regulators will ask about impacts on marine life and existing seabed infrastructure. Running simulations with various burial depths and current profiles allows the team to demonstrate compliance and adjust the route or operating parameters before construction begins. This proactive modeling can prevent costly redesigns or legal challenges later.
A third scenario involves retrofitting aging transmission lines for higher capacity. Utilities often want to boost power flow without rebuilding towers. Simulation can assess whether existing hardware can handle increased voltage without excessive corona. If not, engineers can identify which components need upgrading—insulators, spacers, or dampers—without replacing the entire line. This targeted approach saves millions and reduces outage time.
A Forward-Looking Question
As the power system industry continues to evolve, it is likely that simulation will play an increasingly important role in the design and development of transmission hardware and HVDC submarine cables. However, the accuracy of simulation results depends on the complexity of the model and the available computational resources. How can we ensure that simulation results are accurate and reliable?
Model validation remains the biggest challenge. A simulation can look impressive—a colorful field gradient or a sleek animation of current flow—but if it’s not grounded in real-world physics, it’s just visualization. Best practice involves calibrating models against known test data. For corona, that might mean matching simulated onset voltage to lab measurements on scaled conductors. For EM fields, it could mean comparing simulated magnetic flux density to readings taken near an operating cable.
Another issue is accessibility. High-fidelity simulation tools often require expensive licenses and high-end hardware. Small firms or public utilities in developing regions may lack the resources to run complex models. Open-source tools and cloud-based platforms could help democratize access, but they’re not yet on par with commercial software in accuracy or support.
As renewable integration drives more long-distance transmission projects—many involving submarine cables—the demand for reliable simulation will grow. The industry needs standardized validation protocols, better data sharing, and more collaboration between software vendors, utilities, and regulators. Without these, simulation risks becoming a siloed activity, its full potential unrealized.
Sources: IEEE Spectrum, original report
