Teleprotection Commissioning

Commissioning your Teleprotection Arquitecture

Discover why Utilities are using WAN emulation to validate Teleprotection architectures.

Modern electrical utilities increasingly rely on packet-based communication networks to transport operational data, synchronization signals and teleprotection commands. These systems are essential for maintaining grid stability and ensuring rapid response to faults in the power system.

Before deployment, utilities must verify how protection, synchronization and communication equipment behave under real network conditions. Laboratory validation and field commissioning are therefore critical stages to ensure that the entire protection architecture operates reliably.

For this reason, teleprotection systems depend critically on precise synchronization and predictable communication delays. Any asymmetry between the forward and reverse communication paths can distort the time relationship between measurements and lead to incorrect protection decisions.

Ensuring delay symmetry between communication paths is therefore a fundamental requirement during system commissioning.

The new Smart Grid

In modern substations, protection, automation and synchronization equipment increasingly operate over Ethernet-based communication infrastructures. Utilities must therefore verify, first in the laboratory and later in the field, how equipment responses under realistic traffic conditions.

Several challenges arise in this environment:

• TDM networks provide deterministic QoS but lack flexibility and scalability
• Packet networks improve efficiency but introduce variable delay and require careful engineering
• Validation of IEDs, clocks and teleprotection equipment becomes essential
• Commissioning must reproduce realistic traffic conditions

Unlike dedicated TDM infrastructures, packet networks introduce impairments such as:

• Bandwidth changes
• Asymmetric delays
• Delay variation or Jitter
• Packet loss
• Packet duplication
• Packet reordering

These effects can directly influence the reaction of protection systems. Consequently, utilities must validate how teleprotection and automation equipment work under realistic communication conditions before systems are commissioned.

Hybrid Teleprotection Architectures

Many modern implementations use GOOSE messaging over Ethernet, while numerous utilities still operate legacy C37.94 or TDM-based protection systems, but in many cases these legacy channels are transported over MPLS using pseudo-wires.

Although this hybrid approach is widely used, it introduces an important consideration: MPLS is still based on Ethernet transport and may introduce asymmetric delays between communication paths. These effects must be carefully validated during system commissioning.

Why WAN Emulation Matters

WAN emulators allow engineers to reproduce realistic Ethernet network conditions during system validation and commissioning. WAN emulators can simulate communication links producing traffic impairments. For instance Net.Storm separates traffic  into independent flows using configurable filters, allowing each flow to be treated differently in order to replicate real-world network conditions. Typical impairments that can be reproduced include:

• Bandwidth variations
• Traffic congestion
• Packet loss (single, statistical or burst models)
• Delay based on deterministic or random distributions
• Jitter to emulate packet delay variation
• Packet reordering
• Packet duplication
• Bit errors using configurable probabilities

By reproducing these conditions in the laboratory or directly during field installation, engineers can validate equipment before systems are deployed in substations or MPLS transport networks.

Portable WAN Emulation

Traditional WAN emulators are typically designed for laboratory environments and are often large, expensive and complex instruments. ALBEDO developed Net.Storm with a different philosophy: bringing WAN emulation from the laboratory to the field.  Net.Storm is a portable and self-contained WAN emulator that allows engineers to perform network impairment testing wherever the network is being deployed  indoors or outdoors.

Key characteristics include:

• Fully portable handheld platform with integrated touchscreen and keypad
• Self-contained operation without external laptops or controllers
• Battery-powered design suitable for field installations and substations
• Suitable for both laboratory validation and on-site commissioning
• Zero virtual delay for unaffected traffic flows
• Firmware-based deterministic traffic processing

Firmware-based processing ensures deterministic performance even at high traffic rates, enabling engineers to reproduce realistic network conditions during commissioning activities.

Validating Critical Substation Equipment

WAN emulation plays a key role in validating equipment deployed in modern substations. Using Net.Storm, engineers can verify:

• Protection IEDs and teleprotection equipment
• PTP and NTP clocks
• IEC 61850 communication environments
• PRP redundancy performance
• GOOSE messaging management
• Wireless links introducing delay or packet loss

By reproducing realistic WAN conditions, engineers can observe how equipment reacts before the system becomes operational. This capability is particularly valuable when commissioning complex IEC 61850-based substations where network behaviour can directly influence protection performance.

Testing Delay Symmetry

Some modern routers incorporate mechanisms designed to compensate for asymmetric delays and maintain balanced communication paths. However, these mechanisms must still be validated during commissioning in order to determine their operational limits and ensure that protection systems will operate reliably.

Testing these scenarios requires the ability to simulate controlled delay asymmetry between forward and reverse communication paths.

The Key Capability: Controlled Asymmetric Delay

One of the most important capabilities of a WAN emulator used in utility networks is the ability to generate controlled asymmetric delay. Net.Storm allows engineers to introduce impairments such as:

• Packet loss
• Bandwidth limitations
• Asymmetric delay between communication directions

These capabilities make it possible to reproduce realistic network scenarios and verify teleprotection under real operating conditions.

Portable WAN Emulation for Utilities

Utilities evaluating WAN emulation solutions often consider traditional laboratory platforms from vendors such as Keysight / IXIA or Calnex. These systems provide powerful capabilities but are typically expensive, complex and bulky.

Net.Storm follows a different approach. Its architecture replicates routers and gateways that regulate bandwidth and prioritise traffic flows using well-known bucket algorithms. Two key traffic control mechanisms are implemented:

1. Traffic Policing: Packets that exceed the configured bandwidth limit are discarded while maintaining the timing of the traffic stream.
2. Traffic Shaping: Packets that exceed the configured bandwidth limit are buffered and transmitted later, introducing controlled delay without loss if buffers are not exceeded.

This capability allows utilities to validate protection networks and verify delay symmetry requirements both in the laboratory and directly in the field.

Conclusions

Reliable teleprotection requires precise control and validation of network conditions:

1. Utilities must therefore verify IEDs, clocks and protection systems under realistic WAN impairments before commissioning critical communication infrastructures.
2. Hybrid protection schemes using MPLS transport are increasingly common. While effective, they can introduce asymmetric delays that must be carefully evaluated.
3. Portable WAN emulation platforms such as Net.Storm enable engineers to reproduce delay, asymmetry, jitter and packet loss scenarios both in laboratory environments and directly at installation sites.
4. By bringing WAN emulation from the laboratory to the field, utilities can commission protection networks with greater confidence while significantly reducing operational risk.

A significant number of utilities, integrators, and manufacturers worldwide use Net.Storm, including Schneider, GE, EGAT, ZTI, and many others.