Dynamic Cable Rating with DTS

The need for grid capacity is increasing rapidly due to electrification, industrial development and the connection of new renewable energy. At the same time, building new cable facilities is often both costly and time-consuming. Therefore, it is becoming increasingly important to utilize the capacity of existing infrastructure in the best possible way.

Many cable systems today are operated based on conservative assumptions about environmental conditions, soil properties and load patterns. As a result, the actual capacity is often unknown. Using Distributed Temperature Sensing (DTS), a Dynamic Cable Rating Screening Campaign can be conducted to identify whether there is unused capacity in the cable system.

What is a Dynamic Cable Rating?

A Dynamic Cable Rating (DCR) is a structured survey where a cable system is monitored with a temporary DTS installation over a defined period.

The goal is to:

• Document the cable's actual temperature conditions

• Identifying thermal bottlenecks

• Verify or improve existing capacity calculations

• Evaluating the Potential for Dynamic Cable Rating

• Prioritize which cable systems should be investigated further

The method provides grid companies and industrial facility owners with a cost-effective tool to identify where hidden capacity may lie without extensive investments.

From mapping to analysis

1. Mapping the cable system

Before the measurements begin, a technical review of the cable system is carried out.

This includes:

• Cable type and dimension

• Historical load data

• Laying method

• Soil and environmental conditions

• Operating restrictions

• Previous thermal assessments

This phase forms the basis for planning the monitoring campaign.

2. Temporary DTS installation

A sensor fiber is installed along the cable route or existing fiber is used if available.

The fiber is connected to a DTS unit that delivers continuous temperature measurements with high geographic resolution throughout the entire cable system.

The solution can be installed without major intervention and makes it possible to monitor long cable runs from one central measurement point.

3. Data collection during real operation

Unlike traditional calculations, DCR screening is based on actual operating conditions.

The temperature measurements are combined with:

• Load data

• Ambient temperature

• Weather data

• Operating pattern

• Seasonal variations

This provides a detailed picture of how the cable actually behaves throughout the measurement period.

At the same time, local conditions that may limit capacity are identified, for example:

• Short critical earthworks

• Areas with poor heat dissipation

• Sealed cable trenches

• Crossings and guideways with high thermal load

Dynamic Cable Rating – when actual data replaces conservative assumptions

Traditional cable ratings are often based on "worst case" assumptions. Dynamic Cable Rating, on the other hand, uses actual temperature measurements and real-world environmental conditions to assess how much current the cable can safely carry.

By combining DTS data with thermal models, one can:

• Determine real thermal margin

• Identifying limiting stretches

• Evaluate the possibility of increased load

• Document capacity for new connections

• Postpone or reduce the need for network investments

In many cases, such surveys show that the cable system has significantly greater available capacity than previously assumed.

Reporting and recommended actions

After the campaign ends, all data is compiled into a technical report.

The report describes:

• Measurement setup and assumptions

• Load and temperature history

• Thermal limitations

• Possible capacity increase

• Eligibility for Dynamic Cable Rating

• Proposal for further measures

The result can be used as a basis for decisions regarding operations, reinvestments and future network development.

Why conduct a DTS-based screening?

Dynamic Cable Rating provides:

✅ Better understanding of the actual performance of the cable system

✅ Documentation of temperature conditions along the entire cable route

✅ Identification of thermal bottlenecks

✅ Prioritizing which facilities should be upgraded

✅ Basis for Dynamic Cable Rating

✅ More accurate investment decisions

✅ Potential for increased capacity without new cable installations

From single systems to an entire cable portfolio

For many network owners, it will be appropriate to carry out screening on a number of cable facilities as part of an overall strategy for increasing capacity.

By using mobile DTS systems, multiple cable runs can be systematically examined during a campaign. The results make it possible to identify which cable systems have the greatest potential for Dynamic Cable Rating and where investments will yield the best results.

This provides a data-driven approach to network development, where decisions are based on measured temperatures and documented capacity rather than conservative assumptions alone.

NEKA's approach

NEKA offers complete Dynamic Cable Rating based on DTS technology. We assist with mapping, installation, measurement, analysis and capacity assessment for cable systems in distribution networks, regional networks, transmission networks and industry.

The goal is simple: To provide network owners and facility owners with a documented basis for utilizing existing cable infrastructure in a safer, smarter, and more cost-effective way.