Mission-Critical Communications for Electric Power Utilities – DNWP Connection Master

DNWP Connection Master is designed specifically for mission-critical communication in electricity power utilities. Below, we take a closer look at the solution and the typical applications it supports.

The DNWP Connection Master is purpose-built to handle the unique demands of mission-critical communication within the electricity power utility sector. Unlike standard IT equipment, this solution is designed for the high-availability requirements of the power grid, offering a guaranteed 15++ year production lifecycle and long-term post-manufacturing support.

Applications

Connection Master supports all typical  telecommunication applications in the EPU environment. 

In many cases these are called operational technology (OT) to make a difference to common IT services. A common thing with these applications is their need to communicate between substations or between substation and control center. This is also called Wide Area Networks (WAN) to separate intra substation communication. Service interfaces can be divided into TDM and Ethernet based interfaces Common requirement is also hardware redundancy with dual control and power modules. Connection Master provides solutions for these needs over fiber optic infrastructure.

Substation services over SDH/MPLS-TP -networks

Distance Teleprotection

Various models of the TPS devices can communicate over WAN. Sometimes direct fibre connection is preferred, but also in these cases implementation of the backup path requires utilisation of the telecom network. Distance protection has very high requirements for availability and strict latency specification to fulfill power grid protection fundamentals. Today TPS devices are mainly connected via C37.94 interface, but also other serial interfaces are used like E1, G.703/64k and X.21.

Differential protection

Differential protection schemes are very far away from distance protection, but from a communication point of view it has many similarities. It has even more strict requirements especially for ultra low latency asymmetry. These requirements lead this application eventually to deterministic connection oriented telecommunications like SDH and MPLS-TP. 

Differential protection service users can also benefit from MPLS-TP OAM functions like Delay Measurement (DM) to monitor latency times over the network.  Commonly used interfaces for distance protection are C37.94 and X.21.

SCADA

Supervisory Control and Data Acquisition is a critical function for remote monitoring and control. SCADA consists of two elements, server in control centre and remote terminal units (RTU) in stations. From an operational point SCADA has very high availability requirements and combining this to the long life cycle of RTUs and low bandwidth it’s easy to see why separate OT networks are built for SCADA. There are two commonly used RTU types based on IEC  standards IEC-101 and IEC104 and their difference is the used communications interface. IEC-101 uses V.24 (RS232) asynchronous serial interface and IEC-104 Ethernet interface. Some implementations are made using simple point to point channels. For redundant or shared channels, topologies should be point to multipoint type. C-type data conference over TDM/SDH networks or E-Tree over MPLS-TP. 

IEC61850

61850 is the collection of standards for communication of substations. Part of this data is communication inside the substation, but also between the substations over the WAN. Ethernet over SDH and MPLS-TP Ethernet services can be used for 61850 communication over the WAN. DNWP Connection Master MPLS-TP E-Services filtering configuration can be used to attach 61850 messages to dedicated paths. DNWP Connection Master complies also with IEC61850-3 environmental standards.

PMU

Phase measurement units use IEEE C37.118 protocol over Ethernet for communications. Typical communication network service is Ethernet over SDH or E-line or in case of redundant server E-Tree. Direction in future is the Wide Area Protection and Monitoring where PMU data is used also for grid control, in this case ultra high availability of service is required.

PTP time distribution

Synchronization and time is more and more critical for EPU substation control. There are several clock sources and distribution methods available. Using the same fiber optics networks for synchronization distribution as telecommunication is the most efficient use of assets. SDH networks can provide accurate frequency synchronization also for substation devices, but for time and date information is needed PTP over the MPLS-TP networks. Connection Master MPLS-TP solution can be used for PTP distribution, since it supports common PTP telecom profiles and also C27.238 power profile.

Voice services

In substation communications voice services are related to service and emergency telephones. In many cases analog phones are preferred because they don’t need any auxiliary power feeding and line distances can go up 10km. For analog phone lines are available FXS for subscriber interface and FXO for PABX side. VoIP phones can be also used and PoE can handle power feeding. However for PoE lines maximum cable distance is 100m.

E&M with 2/4-wire voice channels are used for different applications where voice service is used with E&M signalling. Used applications are for example radio links or terminals using voice frequency signalling.

Other

Sometimes these Ethernet/IP services are also considered as operational technology, mainly because of their importance for EPU daily operations. Ethernet over SDH channels or MPLS-TP E-Services can be used to transport them over private networks.

• CCTV
• LAN access to sub station, eg in case of engineering server
• Security channels

Table 1. TDM interfaces

Built for the Grid

In short, DNWP Connection Master delivers deterministic performance, ultra-high availability and hardware redundancy to support mission-critical protection, control and monitoring applications.

With decades-long lifecycle support and proven suitability for WAN-based substation communication, it provides a secure and reliable foundation for the power grid.

Read more on Connection Master product page