1. SPREKERS:
Peter Vaessen
Marc Achterkamp

2. Peter Vaessen
• KEMA Laboratories
• Innovation manager
• Lab development
• TU Delft
• Electrical Sustainable Energy Department
• Head of High Voltage Technologies

3. Increased loading of existing grid-assets, HOW?
1. Use end-of-pipe solutions to gain 15%
2. Tailor made solution for specific bottlenecks
3. Reassessment of capabilities for continuous load
4. Perform additional tests for cyclic and dynamic load
Losses per meter:
~ 17mW J2A
copper conductor (20°C)
with J in A/mm2 and A in mm2

4. Thermal, can it (continuously) deal with the heat?
Load 1
Load 2
Load 3
unstable
stable
What about Ambient?

5. Thermal, can it (dynamically) deal with the heat?
• Typical maximum current densities 1-2 A/mm2 for large conductors, up to 4-5A/mm2 in
transformers and small diameter cables
• Time-constants of thermal phenomena are in the range of seconds to hours, needs to be
determined → overall and hot-spot (when appropriate)
• The higher the current, the more the details become crucial, e.g., a bend in a conductor but
also its shape and orientation
• Some typical figures:
- melting energy copper 0.6kJ/g
- increase of resistance 0.4%/K
- elongation 20µm/m/K
Problem area current
→ overheating
Problem area voltage
→ spark

6. Temperature rise/cycle tests according to IEC standards
1. Cables 60502-2
2. High voltage switchgear 62271-1
3. Distribution transformers 60076-2
4. Instrument transformers 61869-2
Not enough for dynamic loading, additional thermal time constants and hot-
spot (when appropriate) must be determined
+
accurate measurement and protection needed

7. Marc Achterkamp
• KEMA Laboratories
• Metering, Protection & Substation Automation Laboratory
• Type Testing and Certification
• Notified Body MID 2014/32/EU

8. Impact (temporary) overloading on Metering and Protection
• Metering
• Measuring CT saturate >120% rated current Measuring error
• Compliance “Meetcode”?

9. Impact (temporary) overloading on Metering and Protection
• Protection
• Protection relay
• CT inputs protection relay 4 x In continuously
• Protection CT’s
• CT secondary winding rated continuous thermal current

10. Impact (temporary) overloading on Metering and Protection
• Protection
• Settings
• Wide range
• Electromechanical versus Digital protection relays
• Communication to switch between setting groups
• Selectivity

11. BEDANKT
VOOR UW
AANDACHT