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Visual Management of PRP/HSR Networks

When operating a Substation Automation Network (SAN), creating a network management interface of devices and systems using different protocols can create risks and management issues that compromise effectiveness and security.

Fortunately, there is a convenient and practical solution available: an efficient and visually represented PRP/HSR network using Power SCADA with specially designed management middleware can effectively avoid these problems.

Although there is a unified standard for PRP/HSR protocol, there is no standard for the network management interface. But using a native PRP/HSR management server with built-in management middleware can help collect, analyze, and integrate all raw data from various devices on one single management platform. This makes network diagnosis, troubleshooting, and device condition monitoring easier than ever.

Overview

Traditional Substation Automation System (SAS) structure is an end-to-end hard-wired network, so all communication is in real-time and responses are quick. However, when the system has been upgraded to an Ethernet-based network, complications can emerge. The system needs to incorporate Ethernet devices, such as switches and routers. This results in a potential risk of network communication latency due to network topology changes, traffic congestion, or packet queue prioritization. And for mission-critical or time-sensitive applications, even millisecond long network interruptions cannot be tolerated, as they may severely impact system operation or jeopardize onsite personnel safety.

Communicating Partners

Service

Required Communication Recovery Time

SCADA to IED, Client-server

IEC 61850-8-1

400 ms

IED to IED interlocking

IEC 61850-8-1

4 ms

IED to IED, reserve blocking

IEC 61850-8-1

4 ms

Protection trip excluding Bus Bar protection

IEC 61850-8-1

4 ms

Bus Bar protection
(GOOSE)

IEC 61850-9-2 on station bus

Bumpless

Sampled Measured Values
(SMV)

IEC 61850-9-2 on process bus

Bumpless

What are PRP/HSR protocols and how are they used?

The Parallel Redundancy Protocol (PRP) and High-availability Seamless Redundancy (HSR) protocols described in IEC 62439-3 are two technologies that provide seamless failover from a single point of failure. Based on these two seamless redundancy protocols, a redundancy box (Redbox) can quickly activate non-HSR or non-PRP end devices connected to HSR or PRP networks with zero switch-over time. Mission-critical applications in SAS communication can benefit from these redundancy technologies to ensure network reliability.

Challenges Faced:

1. Redundant network monitoring and troubleshooting

  • MAC and IP address network management systems cannot detect if a packet has been duplicated by PRP/HSR
  • System administrators will not know the redundant network’s real-time status, or will be unable to troubleshoot any failed redundant paths.

2. Un-unified device and network management interface

  • An increasing number of networking devices such as industrial Ethernet switches and embedded computers have been implemented in the IEC 61850 system.
  • Many do not run on Manufacturing Messaging Specification (MMS) protocol.
  • Today’s most common protocol for managing IT equipment is Simple Network Management Protocol (SNMP).
  • PRP/HSR devices use Supervision Frame for device management.

Hence, while MMS devices are normally visible to Power SCADA, SNMP or Supervision Frame networking devices are not, so it can be difficult to manage both control devices and networking devices in a centralized manner.

Recommended Solution:

Control devices and redundant networks are monitored on a PRP/HSR-capable Power SCADA management server

The best use of native PRP/HSR substation computers is to deploy a PRP/HSR-capable Power SCADA management server. With some specially designed PRP/HSR management middleware, the PPR/HSR management server can enable the Power SCADA to collect and analyze the raw data from various distributed devices. The PRP/HSR management middleware is designed to support both SNMP and MMS interfaces. The current redundant network status can be fully monitored, and a single-point failure can be immediately discovered. This makes real-time troubleshooting a simple task.

Even system administrators with little knowledge of PRP/HSR technology can easily manage, monitor, and troubleshoot the PRP/HSR network on a single Power SCADA platform.

Substation operators find it easy to manage all devices on the PRP/HSR system using the Power SCADA’s simple, clear and effective visual tools. In addition, troubleshooting can be easy, as any single failure point can be shown on the Power SCADA, making the SAS or any other PRP/HSR applications more reliable and stable.

This solution makes network diagnosis, troubleshooting, and device condition monitoring reliable, efficient and easy.

If you would like to know more about PRP/HSR network management, please download Moxa’s white paper here.

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