IEC 61850 for Power Quality — solving the PQA integration problem

IEC 61850 has solutions for a lot of systems where currents and voltages are crucial ingredients of a system. Click HERE for a list of use-cases.

One of the practical challenges for TSOs (Transport System Operators) and DSOs (Distribution System Operator) is the integration of Power Quality Analyzers into utility monitoring systems. 

Traditionally, each PQA (Power Quality Analyzer) manufacturer has its own communication interface, data structures and software tools, so integrating equipment from different vendors often requires developing and maintaining vendor-specific drivers, especially when detailed PQ parameters and events are involved. IEC 61850 offers a good way to address this problem. 

Vendors like SATEC offer PQA ... e.g., PM180 is an example of a Class A Power Quality Analyzer where IEC 61850 is used not only for basic electrical measurements, but also for Power Quality information. PQ parameters, harmonics, frequency-related information, events, alarms and status can become part of the IEC 61850 information environment instead of remaining accessible only through a proprietary PQA interface. 

Client/Server (Reporting etc.) can be used for measurements, PQ parameters, events and monitoring, while GOOSE provides fast exchange of event and automation information. PMU functionality is also available for synchronized measurement applications. For a TSO or DSO, the key benefit is architectural: instead of integrating every new PQA through another proprietary driver, Power Quality devices can become part of the same IEC 61850 infrastructure already used for other substation IEDs.

Click HERE for accessing the corresponding ICD document (IED Capability Document).

The new IEC 61850-7-440:
Basic communication structure –
Compatible logical node classes and data object classes – Power quality metering

will contain the following PQ specific Logical Nodes (currently in IEC 61850-7-4 Ed2.1):

• Flicker measurement Name: MFLK 
• Harmonics or interharmonics Name: MHAI .
• Non-phase-related AC harmonics and interharmonics Name: MHAN 
• Metering single phase Name: MMTN
• Metering 3 phase Name: MMTR 
• Frequency variation Name: QFVR 
• Current transient Name: QITR 
• Current unbalance variation Name: QIUB
• Voltage transient Name: QVTR 
• Voltage unbalance variation Name: QVUB 
• Voltage variation Name: QVVR

Other vendors have similar PQAs ...

What is the Scope of the IEC 61850 Series?

The seven IEC 61850 CDVs published the other day (7-4, 7-4n and 7-4nn) use all the same Scope which starts:

Excerpt from:

Communication networks and systems for power utility automation – Part 7-4: Basic communication structure – Compatible logical node classes and data object classes – Core

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1.1 General

This part of IEC 61850 specifies the information model of devices and functions generally related to common use regarding applications in systems for power utility automation. In particular, it specifies the compatible logical node names and data object names for communication between intelligent electronic devices (IED). This includes the relationship between logical nodes and data objects.

...

This standard and its direct counterparts (7-4, 7-4n and 7-4nn) are applicable to describe device

models and functions for:

• substation and feeder equipment,
• substation-to-substation information exchange,
• substation-to-control centre information exchange,
• power plant-to-control centre information exchange,
• information exchange for distributed generation,
• information exchange for distributed energy resources,
• information exchange for metering,
• information exchanged for hydro power plants, or
• information exchange for wind generation plants.

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The main title of all parts of the series IEC 61850 is: 

Communication networks and systems for power utility automation 

This title is some how an indication of the scope.

IEC 61850 can be used everywhere as follows:

Communication networks and systems for power utility automation

The narrow scope to power utilities is sometimes used by people that do not like the IEC 61850 series ... or do not want to let people outside the power utilities to apply it ... 

But the crucial content of the many different parts is applicable in most automation domains ... where ever electric power is found - buildings, factories, ... 

A lot of Logical Nodes, e.g., STMP (Supervision of Temperatures) are useful for transformers, bearings, tanks, ... 

Lessons learned:

1. The various parts of IEC 61850 are applicable far beyond of the written scope - if you like it or not.
2. Often the discussion related to the scope is aimed to tell you, that IEC 61850 is not applicable outside power utilities (or substations) - trust me: it is applicable far beyond.

By the way, the discussion of scopes could be ridiculous: IEC 60870-5-104  defines:

"This part of IEC 60870 applies to telecontrol equipment and systems with coded bit serial data transmission for monitoring and controlling geographically widespread processes. It defines a telecontrol companion standard that enables interoperability among compatible telecontrol equipment"

IEC 60870-5-104 does not have substation automation (usually not a widespread area) in its scope - BUT, you know 104 is used as the communication inside many substations! Ok ... why not. But then also IEC 61850 can be used for telecontrol ... see IEC 61850-80-1, ...
In the wind power industry it was discussed some 20 years ago: IEC 61850 is not applicable for wind turbines, because wind turbines are not substations ... hahaha

Enjoy IEC 61850!