Interoperable information and communication technologies ...

Interoperable information and communication technologies from the

electricity socket up to the network control centre

Ch. Brunner, IT4Power, Switzerland

B. M. Buchholz, NTB Technoservice,

Germany

A. Naumann, Otto von Guericke University Magdeburg

Summary

The enhancement of distribution networks into smart grids is accompanied by new functions

and technologies like:

• Energy management on distribution level,

• Distribution system automation,

• Smart metering,

• Smart building automation and involvement of consumers into the energy market.

All these technologies require an intensive exchange of data. As a consequence, the

information and communication technology (ICT) will penetrate the distribution systems

down to the end customers (Consumers and/or producers) on the low voltage network.

Today on the different control levels of electric networks various communication protocols

and information systems are applied. The data models and services of these systems are

different and do not allow seamless information exchange between the levels:

• Network control center – substations, traders, power plants and virtual power plants

• Inside the substations,

• Substation – medium and low voltage (MV and LV) distribution networks and its

consumers and power producers,

• Inside the buildings and industrial enterprises.

As a result of the analysis, the demand of information exchange of all participating clients is

defined. The function, the integration into the ICT system and the services of new

stakeholders in the smart grid environment like “Virtual Power Plants”, “ICT provider” or

“Metering service provider” are considered.

For economic reasons, the communication technology in the distribution level should be

based on the existing infrastructure. Depending on the location the most economic technology

can be applied like Distribution Line Carrier (DLC), radio, telecommunication cables (copper

ore fiber optics).

Otherwise there is a strong need that the data models and the services of the communication

system will be uniform for the overall network control and data acquisition. The paper

describes how the data models and services of IEC 61850 will be applied for this purpose.

The power network wide application of IEC 61850 data models and services shall be

supported by standards for gateways:

• To home automation and smart meters (were simplified models and services are applied),

• To data base systems using Common Information Models (CIM / IEC 61968).

Relevant efforts in the IEC working groups are considered. Recommendations about further

standardization efforts are given.

Finally, the paper describes the pilot application “Web2Energy” - a European lighthouse

project funded by the European Commission.

1. Smart Distribution

The establishment of Smart Grids in the distribution level is driven by the European Targets

20-20-20 in 2020 what means 20 % reduction of carbon emissions, 20 % share of renewable

energy in the primary energy balance and 20 % increase of energy efficiency. A significant

contribution to achieve these targets will come from a new quality of distribution networks

providing the three pillars of “Smart Distribution systems”:

• Smart Terminal: Self-healing capabilities for the distribution networks based on ICT-

enabled response and thus automated fault elimination in MV feeders to increase the

reliability of supply significantly.

• Smart Aggregation: Active distribution networks with flexible and reconfigurable

aggregation and management of distributed secure and unsecure (fluctuating) power

sources, storage and controllable loads in virtual power plants. The goal is to reach an

optimum combination of environmental protection (lower CO2 emissions) and

economical value.

• Smart Metering: Customer integration into the electricity market by variable tariffs

effecting efficient demand-side management and response to improve the efficiency of

energy production, to achieve energy savings and to reduce peak power demand, leading

to lower system costs and improved embedding of renewable energy sources.

The new functions are demonstrated in Figure 1.

Dat

a C

olle

ctio

n

+ -

smart meteringsmart terminal automation

smart energymanagement

Dyn

amic

tariffs

Market

Billing

Home automation

• Remote reading of short circuit indication•Remote control of switches•Shorting supply interruptions after faults from hour to minutes

• Aggregation of dispersed generation with and without secure production for flexible market participation•System service provision•Scheduling and balancing

• Market integration of consumers - motivation for load shifting through variable tariffs•Higher efficiency of metering processes

+ - + -

QVL

+ -

VPP

Figure 1 – The pillars of smart distribution

The realization of the 3 pillars of smart distribution requires the wide spread implementation

of advanced technologies which are still not broadly applied today:

• Smart meters which are remotely readable and which can operate with variable tariffs

through receiving and visualizing tariff signals,

• Communication facilities for data exchange on all levels of the power system down to the

LV consumers,

• Building automation facilities to achieve higher efficiency of electricity use in households,

business and industry.

In the first priority, communication links have to be established until the last meters to

consumers.

2. New quality of information exchange in the distribution level

Today, an ICT infrastructure for control and supervision of distribution networks is not

widely and extensively applied to the medium and low voltage levels. Communication for

power system control currently ends at the MV- busbars of the substations 110 kV/ MV.

Secondly, the existing communication networks for control in the upper level of the power

system are mostly owned by the grid operators. Different communication standards are

applied for different control levels like:

• inside the substation,

• between substation and network control centre,

or for different equipment like

• protection relays,

• meters,

• switchgear and transformers.

The current situation is shown on the left side of

Figure 2 - Communication in power systems today and in the future

The current situation causes high engineering efforts for converting between the various

communication levels. Various interface testers and diagnosis tools have to be applied.

future the communication has to move down and cover the whole distribution system.

Furthermore, uniform data models and services have to be used an all levels.

distribution level public communication networks should be used

available and most economical

telecommunication cables or radio.

In the normal case, several telecommunicati

networks. They are able to take over the functions of “Communication Providers for Smart

Distribution”. The stakeholders of the electricity business in distribution systems like the

trader, the distribution network operator or the virtual power plant operator should conclude a

between substation and network control centre,

or for different equipment like

switchgear and transformers.

hown on the left side of Figure 2.

Communication in power systems today and in the future


els. Various interface testers and diagnosis tools have to be applied.


data models and services have to be used an all levels.

distribution level public communication networks should be used adapting

most economical communication physics e.g. power line carrier,

telecommunication cables or radio.

In the normal case, several telecommunication providers cover the areas of the distribution

They are able to take over the functions of “Communication Providers for Smart


network operator or the virtual power plant operator should conclude a


els. Various interface testers and diagnosis tools have to be applied. In the


data models and services have to be used an all levels. Thirdly, in the

the locally

communication physics e.g. power line carrier,

on providers cover the areas of the distribution

They are able to take over the functions of “Communication Providers for Smart


network operator or the virtual power plant operator should conclude a

common contract with the communication provider in their area offering the best ratio of

prices and services.

The meters and the remote terminal units on the consumer or producer side b

servers which will use a dedicated or a dial

should offer flat- rates for both types of connections.

Figure 3 – Data content for information exchange

The data which will be exchanged between the clients (control levels) and the servers

presented in Figure 3.

3. IEC 61850 - the core standard of Smart Grids

Today, we can see worldwide a broad consensus that the data models and services of IEC

61850 will be used in the smart distribution grids.

• IEC 61850 is the first communication standard for power automation which is globally

accepted.

• IEC 61850 provides generic object oriented and self describing data models

logical nodes (LN) attributes and data cla

• The data models are open for any extension if requested in the future.

• IEC 61850 is open for new

• The services of the previous standards are not only kept but s

extended. The GOOSE service, for example,

and lead to a fundamental improvement of the performance.


The meters and the remote terminal units on the consumer or producer side b

servers which will use a dedicated or a dial – up connection. The communication provider

rates for both types of connections.

Data content for information exchange

e exchanged between the clients (control levels) and the servers

the core standard of Smart Grids


ll be used in the smart distribution grids. The reasons for this trend are obviously:

IEC 61850 is the first communication standard for power automation which is globally

IEC 61850 provides generic object oriented and self describing data models

des (LN) attributes and data classes.

The data models are open for any extension if requested in the future.

IEC 61850 is open for new communication physics and link layers.

The services of the previous standards are not only kept but significantly

The GOOSE service, for example, allows a quick peer- to- peer communication

and lead to a fundamental improvement of the performance.


The meters and the remote terminal units on the consumer or producer side build the data

up connection. The communication provider

e exchanged between the clients (control levels) and the servers is


The reasons for this trend are obviously:

IEC 61850 is the first communication standard for power automation which is globally

IEC 61850 provides generic object oriented and self describing data models based on

ignificantly improved and

peer communication

• The technical committees of IEC are working on standard extensions for further

applications like “power quality”, “dispersed generation”, “hydro power plants” and

“wind power plants”. The standardization process is still ongoing.

In this sense, the IEC 61850 application layer

physical and application layers as shown in

Figure 4 – Reference model of IEC 61850 using various layers 1 and 2

On the left side of Figure 4 the current coverage of the OSI/ISO layers is shown in accordance

with the mapping on Ethernet

The application in distribution networks can use all types of physical media. A specific

communication mapping will adapt the layer 7 for a seamless interaction with the lower

layers. But the data models (IEC 61850

(ACSI - abstract communication service interface

In this way it can be ensured that

and clients in the substations and in the distribution level.

most economical communication channel

area is now open!

One of the first projects applying IEC 61850 to provide the

distribution is the project “Web2Energy

The reference architecture of the whole information and communication system (ICT)

developed for this pilot application

This figure demonstrates that IEC 61850 is the core standard for communication. However,

the complete ICT system needs more.

The technical committees of IEC are working on standard extensions for further


The standardization process is still ongoing.

application layer is suitable for combination with different

plication layers as shown in Figure 4.

rence model of IEC 61850 using various layers 1 and 2

the current coverage of the OSI/ISO layers is shown in accordance

with the mapping on Ethernet as it is defined in IEC 61850-8-1 for substations.


g will adapt the layer 7 for a seamless interaction with the lower

(IEC 61850-7-4xx and IEC 61850-7-3) and the abstract

abstract communication service interface - IEC 61850-7-2) will be kept identical.

ay it can be ensured that the communication uses the same semantic

and clients in the substations and in the distribution level. Furthermore, the way to apply the

most economical communication channel which is available in the infrastructure of the supply

One of the first projects applying IEC 61850 to provide the complete functions of smart

Web2Energy” [1] which is funded by the European Commission.

architecture of the whole information and communication system (ICT)

pilot application is presented in Figure 5.


ICT system needs more.

The technical committees of IEC are working on standard extensions for further


is suitable for combination with different

the current coverage of the OSI/ISO layers is shown in accordance

1 for substations.


g will adapt the layer 7 for a seamless interaction with the lower

the abstract services

will be kept identical.

semantic for all servers

Furthermore, the way to apply the

available in the infrastructure of the supply

functions of smart

” [1] which is funded by the European Commission.

architecture of the whole information and communication system (ICT)


First of all, the security and the performance of information exchange shall be on a high level

“smart” and fulfill advanced expectations. Therefore, the standard

needed approaches and requests that this part

Secondly, the stakeholders of the power supply process (on the terminology of

communication: clients) use data base system for operations. In the past each vendor

implemented its own data base with proprietary formats

SCADA, Geographical information system (GIS)

However, a big amount of data is relevant for different data bases and if one data will be

changed than it had to be done in several applicati

time. This variety of data bases inside on

the various applications. To overcome this issue, IEC 61968 defines UML based Common

Information Models (CIM) for all

Figure 5 – ICT reference architecture of Web2Energy

The project Web2Energy will use the CIM

exchange between the data bases will be possible without any conversion.

A further issue is the fact that meters still use their own communication protocols

based on standards, partly proprietary protocols depending on the vendor and the sales region.

The same situation is valid in the area of building automation. A market participation of the

electricity consumers will include the action of an “energy butler”. This intelligent electronic

device controls the internal generation

households where the time of operation is not important for life convenience

machines, dish washers, air conditioner


“smart” and fulfill advanced expectations. Therefore, the standard IEC TS62351

needed approaches and requests that this part of smartness will be achieved also.

the stakeholders of the power supply process (on the terminology of


emented its own data base with proprietary formats for different applications like

SCADA, Geographical information system (GIS), Asset Management or network planning.


be done in several applications with different data formats in the same

time. This variety of data bases inside one enterprise often leads to inconsistency of data in

To overcome this issue, IEC 61968 defines UML based Common

Information Models (CIM) for all data requested in the distribution network management [2].

ICT reference architecture of Web2Energy

The project Web2Energy will use the CIM model in the data bases of all stakeholders. A data

bases will be possible without any conversion.

A further issue is the fact that meters still use their own communication protocols




the internal generation / storage units and some switchable devices in the

households where the time of operation is not important for life convenience

, air conditioners or heaters.


IEC TS62351 defines the

of smartness will be achieved also.

the stakeholders of the power supply process (on the terminology of


r different applications like

et Management or network planning.


ons with different data formats in the same

consistency of data in

To overcome this issue, IEC 61968 defines UML based Common

data requested in the distribution network management [2].

in the data bases of all stakeholders. A data

A further issue is the fact that meters still use their own communication protocols – partly




switchable devices in the

households where the time of operation is not important for life convenience like wash

Based on price signals from the higher communication level the butler ensures an optimum

ratio of services and costs inside the households or in the industry. The complete ICT system

has to consider the variety of these influences to become seamless.

4. Gateways

4.1. IEC 61850 data model - CIM data management

The data management of all clients

common information models. Consequently, the incoming and outgoing information to and

from the other system components has to be converted between IEC 61850 and CIM.

Figure 6 – Relation between CIM and IEC 61850 modeling

The data model of IEC 61850 presents the current value

In Figure 6 a metered value is

TotWh for metered energy and the attributes actVal

number of counted pulses, pulsQty

units e.g. in accordance with the SI system and finally

The amount of data in the CIM data base is significantly higher

information is stored and the actual metered value builds only a pixel in the whole

presentation of the meter.


atio of services and costs inside the households or in the industry. The complete ICT system

has to consider the variety of these influences to become seamless.

CIM data management

The data management of all clients in project Web2Energy is consequently based on the



Relation between CIM and IEC 61850 modeling

The data model of IEC 61850 presents the current value and metadata of this value.

presented by the Logical Node MMTR for meter, the data class

ed energy and the attributes actVal – the actual value expressed in the

number of counted pulses, pulsQty – the puls quality in Wh/puls, Units to define the applied

units e.g. in accordance with the SI system and finally t - the time stamp.

data in the CIM data base is significantly higher – the general meter



atio of services and costs inside the households or in the industry. The complete ICT system

in project Web2Energy is consequently based on the



and metadata of this value.

MMTR for meter, the data class

the actual value expressed in the

the puls quality in Wh/puls, Units to define the applied

the general meter


The IEC 61850 – CIM Converter has to define the locality of the submitted values and adapt

them how it is shown in Figure 6. The Web2Energy project will develop standard converters

for these gateway functions.

4.2. Meter and smart building communication

Currently there is no chance to implement IEC 61850 at the communication levels of meters

and building automation. The communication at these levels should be simple – services and

openness of data models don’t play a role. For this reason a large amount of proprietary

solutions and standards was developed and applied.

On the other side, the amount of data which is common on the lower levels of meters or

building automation and network control is low. In principle, it contains the metered values,

the price signals and the tariff forecast – much less in comparison with the thousands of data

required for power system control.

Figure 7 - Gateways between meter/ building communication and the system WAN based on IEC 61850

The energy butler in the buildings in principle needs only the tariff signal and the tariff

forecast from the system level. It can be received directly from the WAN or through the

meters as shown in Figure 7.

The meters communicate inside a closed system to a data server. Meters of other media like

water, gas, heat are incorporated in this system.

Therefore, in the project Web2Energy the converter for IEC 61850 based provision of

metered values to the clients is allocated in the data server.

Nowadays, there run activities to define a common simple and efficient communication

structure for the multi-utility metering [3-5]. In Europe the favorites are the M-Bus (wire and

wireless) with SML in the application level. Hopefully, in the field of building

communication favorites like KNX [6] or Bacnet [7] can achieve in mid- term the status of

common standards in Europe as well.

5. Common data models from the consumer socket up to Control centers

The application of IEC 61850 as a core standard of Smart Grids is strongly supported by

several working groups in IEC.

Today it is possible to use the common data models in all levels of power system control as

presented in Figure 8.

Figure 8 - Coverage of the power system levels by common data models

At the level between substations and Control centers a global and widespread use found the

standard IEC 60870-5-101 (point to point) and -104 (WAN). The weakness of this standard is

that the data have to be defined in the engineering process by assignment of numbers –

uniform on both sides. This approach requires expensive engineering and leads often to

inconsistencies.

But it is more expensive to change the running communication systems and to introduce IEC

61850 with all its convenient services. The short term solution is now offered by IEC 61850-

80-1: Mapping the data models of IEC 61850 to the structures of IEC 60870-5-101/4.

In the lower levels new consistent data models are brought to standards – for hydro power

plants, for dispersed generation and for wind power plants as shown in Figure 8.

IEC is still open to take off further data models if the need is demonstrated in pilot projects.

This extension is a further target of the Web2Energy project.

Today, the working group (WG) 10 of the IEC technical committee (TC) 57 is responsible for

all the generic parts of IEC 61850 that are not domain specific as well as for the parts related

to the substation automation. For other domain specific parts, specific working groups exist:

• WG17 for dispersed generation

• WG18 for hydro power plants

• TC88 / Project team 25 for wind power plants

It is planned, to establish a coordination group to ensure consistency of the modeling across

the different working groups. It is as well intended to publish in the future the complete set of

data models for the different domains as a database. This as well to facilitate the reuse of

already defined models from one domain in another domain – e.g. elements that have already

been defined in the context of hydro power generation may be reused for thermal or nuclear

generation.

These activities show: In the context of “Smart Grids”, the interoperable data exchange over

all levels from the electricity socket up to the network control center is toady a reachable

target.

6. Application of IEC 61850 Data Models for Smart Distribution

In the framework of the lighthouse project Web2Energy the data models for implementation

of the 3 pillars of smart distribution are defined in accordance with Figure 3. A standard data

model exists in the published documents for the most of data to be exchanged.

Figure 9 – Three pillars of smart distribution and the relevant data models

However, each of the application requires more or less new data models.

comparison of some available and additionally proposed data models

Web2Energy has the target to extend the related standards accordingly.

7. New service providers in the environment of smart distribution

Smart Meters with communication facilities are offered on the markets for other media as

well. Advanced concepts are focused on a common multi

distribution to the relevant stakeholders

via a multi-utility controller MUC as presented in

protocols are applied.

Figure 10 – System with data acquisition from various multi

The metering service provider is responsible for the data acquisition of the metered values.

the next level the information provider selects the required data for the various stakeholder

functions, e.g. trader, VPP or DNO

compressed data into the IEC 61850 protocol. The information provider serves other markets

in the same way: selection and compression of the required data for each stakeholder with the

subsequent conversion into the requested communication protoco

A further market role is the ICT provider who offers the requested physical infrastructure for

communication.

Three pillars of smart distribution and the relevant data models - examples

However, each of the application requires more or less new data models. Figure

available and additionally proposed data models used in Web2Energy.

Web2Energy has the target to extend the related standards accordingly.

in the environment of smart distribution


well. Advanced concepts are focused on a common multi-utility data acquisition and

to the relevant stakeholders. The communication of the various meters i

utility controller MUC as presented in Figure 10 [5]. At this level

System with data acquisition from various multi-utility meters

ing service provider is responsible for the data acquisition of the metered values.


VPP or DNO on the electricity supply field and converts the



subsequent conversion into the requested communication protocols.


examples

Figure 9 presents a

used in Web2Energy.


utility data acquisition and

various meters is bundled

At this level the meter

ing service provider is responsible for the data acquisition of the metered values. At


erts the




8. Conclusions

A first experience regarding the implementation of the 3 pillars of smart distribution is

achieved in the European Lighthouse project “Web2Energy” by strictly use of the most

advanced IEC standards for communication and data management. Today the standards do

not cover the whole amount of information which is requested in the practice. The need for

further extension is considered.

The pilot applications are necessary

• to qualify the standardization work,

• to investigate new approaches and services including the relevant business models

• to recognize legal and regulatory barriers and demonstrate alternatives

In the context of “Smart Grids”, the interoperable data exchange over all levels from the

electricity socket up to the network control center is toady a reachable target.

9. References

[1] www.web2energy.com

[2] www.smartgrids.eu, SmartGrids Strategic Deployment document, Deployment Case 4.

[3] www.dlms.com

[4] www.figawa.de

[5] www.m-u-c.org

[6] www.knx.de

[7] www.bacnet.org

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