Test Case 19

19

Merkebu Zenebe, Tesfaye Amare, Petra Raussi, Aro Matti

1

ERIGrid 2.0

28/4/2021

Evaluation of unintended impacts of activation of flexibility resources on the quality of supply

Flexibility services have the potential to negatively affect local power quality. These unintended impacts might be a result of large amounts of flexibility resources and related power electronics under same distribution feeder.

Unintended impacts might also result from mis use of flexibility controllers if an attacker is able to breach the communication between controller and flexibility resource.

Unintended impact is evaluated mainly on the quality of supply but also on the ICT connections.

The function under investigation is the activation of flexibility resources.

• Local or Remote controller
• The communication infrastructure between the controller and the flexibility resource.
• A flexibility resource on the demand side.

• Electric Power system
• ICT/Control System

PoI#1: Characterization of impacts of activation flexibility resources on QoS

PoI#2: Characterization of the communication technologies used for flexibility activation for their vulnerabilities towards misuse case.

The test system includes large distribution network, customer loads with variety of flexibility resources (shiftable loads, hot water tanks, home EV charging stations …etc). In addition, an aggregator/DSO with responsibility of activation of flexibility resources implicitly or explicitly. The underlying ICT infrastructure for both control and price signal communication is also part of the test system.

• DSO function: Peak shaving
• Customer function: Load generation balancing / maximize self-consumption
• Energy retailer function: day ahead market participation
• TSO function: frequency regulation

• The flexibility resources shall be able to provide the requested service on time and within the requested capacity (PoI#1)
• The activation of flexibility resources shall not increase network losses, voltage quality problems or additional peaks in the network (PoI#1)
• The communication infrastructure in place shall not create new vulnerabilities for mis use cases. Also, it shall communicate control and price signals with acceptable level of latency. (PoI#2)

Flexibility service-related metrics:

• Capacity (MW)
• Duration (t)
• Ramp rate (dP/dT)

Unintended impact related metrics:

• Network loss (reactive power flow) (kWh)
• Overloading of network components (% of rating)
• Blackout probability (Load Altering Attack related metrics, in relation to natural frequency of grid, possibility for frequent switching?)

Communication infrastructure related metrics (adequacy):

• Latency
• Packet loss

• Type and volume of flexibility resources
• Type and requirements of service requests
• Electrical grid configuration
• Peak/off-peak time (affects the probability of creating local peaks)
• Cyber-attack behaviors
• Type of communication technology used and traffic behaviors:
• Failure rate of components

• For voltage quality measurements, the measured value should not be below 0.95 pu ? or above 1.05 pu?
• Total harmonic distortion
• Vulnerability for LAA (Pass/fail)
• Overloading (%rating) threshold varies for transformers, overhead lines and underground cables.