DLMS/COSEM protocol on trial in the Netherlands

There is little practical experience of the standardised protocol DLMS/COSEM in the Netherlands at present, and a pilot project is therefore being carried out on behalf of EnergieNed in a joint venture between KEMA, Gastec and various Dutch energy companies. 

In a liberalised energy market different suppliers can offer energy via one common infrastructure. By regularly changing supplier it is possible to get the cheapest energy (whether or not this is combined with the best value-added services) in our homes. All energy consumers in the Netherlands will be able to choose their suppliers from 2004. 

To invoice this energy it is important to be able to make a distinction between the ‘energy products' of different suppliers. It must therefore be possible to take meter readings quickly, and remote measurement, combined with automatic data collection, is a reliable and efficient technique. There are various communication protocols for telemetry and data collection. The Netherlands Standardization Institute (NNI) has recently recommended the protocol DLMS (IEC 61334-4-41) for this purpose[1], preferably implemented using the object model COSEM (draft IEC 62056-62). The COSEM specification uses object-modelling techniques to provide a view of the functionality of the metering equipment, since it is available at its interface[2].

An integral approach was sought when drawing up the NNI recommendation, and the aim was to be able to use the same protocol for the exchange of meter readings for electricity, gas, water and heat. The great advantage of DLMS/COSEM is that this is an open (standardised) protocol – there is no need to be dependent on one supplier. 

In May 2000 the Dutch organisation for energy companies, EnergieNed, organised an international symposium to draw the attention of the target group to the possibilities of DLMS/COSEM. One of the conclusions of this symposium was that large numbers of energy meters will have to be replaced or adapted for telemetry as soon as the liberalisation of the energy market really gets underway[3]. Suppliers of meter products must therefore be convinced of the need to implement DLMS/COSEM as soon as possible.

SUPPLIER DEPENDENCE

Telemetry equipment is being fitted for many customers who are already free to choose their suppliers in the electricity sector in the Netherlands. The mains and metering companies are, however, still faced with the dominant position of one supplier. If the data collection system used comes from this supplier, they are forced to buy meters from the same supplier to avoid problems of incompatibility. For the mains and metering companies this creates many disadvantages, such as:

  • Great dependence on this one supplier
  • Little or no freedom of choice when buying energy meters
  • Little flexibility in functionality
  • Higher costs due to lack of competition 
  • Less incentive for the supplier to improve quality.

All these disadvantages are eliminated if DLMS/COSEM is used. Now it becomes possible to read the meters of different manufacturers from one data collection system, thus reducing prices and increasing quality. In addition the exchange of metered data is easier and more flexibility is offered – an important factor in a liberalised market. However, all this can only be achieved if the energy world itself asks for meters in which DLMS/COSEM is implemented.

PRODUCTS

Three manufacturers of electricity meters have already implemented DLMS/COSEM in some of their meters – Siemens, Schlumberger and Deutsche Zählergesellschaft (DZG). In the Netherlands the first meters will be taken into service this year. No suppliers of gas, heat and water meters use DLMS/COSEM; they are holding back for the present, and also waiting for the standardisation of COSEM to be completed. However, one manufacturer of gas meters has promised to implement a DLMS/COSEM interface in the near future, and we expect that in 2001 a lot more DLMS/COSEM-based products will appear on the market. 

To read DLMS/COSEM-based energy meters, the MV-90 and C2000 data collection systems commonly used in the Netherlands will have to be adapted. The suppliers of MV-90 and C2000, Itron and Siemens, have already stated that they will adapt their systems to use DLMS/COSEM. This development will also take place in 2001, but the DLMS/COSEM products will still not be available to those customers from the first and the biggest part of the second tranche of those who are able to switch suppliers (the big and medium-sized energy consumers). However, commercial companies recognise the need to obtain meter data from certain groups of customers from the third tranche (the small consumers such as households) which will be available from 2004. DLMS/COSEM will not be too late for this group, and they will be able to make use of the advantages that the protocol offers.

PRACTICAL TRIAL

The pilot project is being carried out to obtain more practical experience of DLMS/COSEM. It is being done parallel to some trials in Germany. During the trial the correct functioning of the meter products and the data collection systems will be tested. An important aspect is to investigate if the functionality specified as a minimum for such metering in the Metering Code of the Dutch Office for Energy Regulation (DTe) is actually implemented in the DLMS/COSEM products. In particular the trial will look at the so-called ‘plug and play' character, with which the energy meter can automatically be configured.

Two different tests are necessary to verify the connectability of energy meters to data collection systems. First the conformity of the individual energy meters must be tested. This conformity test must establish whether the meter communicates in accordance with DLMS/COSEM. It forms the basis for getting a guarantee that the protocol has been properly implemented. A conformance test system is needed, which has been specified by the conformance testing working group of the DLMS User Association. Although it still has to be developed by an external supplier, we hope to be able to use it for the pilot project. 

Then the various data collection systems must be tested to determine whether energy meters from different manufacturers with a variety of functionality can communicate correctly (interoperability). The test plan to be used in the practical trial describes both forms of test, to demonstrate the connectability of the whole system.

TEST ROOM

A special laboratory test room will be set up at KEMA Consulting, where energy meters can exchange data with a data collection system. The three electricity meters fitted with a DLMS/COSEM interface and the data collection systems MV-90 and C2000 will be involved in the first phase of the practical trial. The manufacturers of these systems have promised their co-operation. 

One of the meters will not be set up in the test room; instead it will be coupled with the data collection systems via a modem link with the manufacturer in Germany. We have also made contact with suppliers of gas, heat and water meters, and will subject these meters to the same practical trial once they have been equipped with a DLMS/COSEM interface.

TRIAL RESULTS

KEMA Consulting Arnhem recently carried out a similar and very successful pilot project with the protocol IEC 60870-5-104. This showed that such a project can stimulate knowledge and innovation, both on the part of energy companies and their suppliers. The testing and assessment of components used in a pilot project has a favourable effect on uniformity and thus reduces costs for the energy companies.

The results of the DLMS/COSEM practical trial will be distributed within the energy world. If they are positive, it will clear the way for a broad acceptance and large-scale implementation of the system in the Netherlands. Suppliers of meter products from the electricity, gas, heat and water sector will take advantage of this and will develop products in accordance with the DLMS/COSEM protocol. The final objective of the practical trial is to encourage the Dutch energy companies to have confidence in the system, so they can change over to large-scale procurement of DLMS/COSEM meters.

References

1. Netherlands Guide of Practice NPR 6233, “Remote reading of meters – Data collection protocols”, Netherlands Standardization Institute (NNI), Delft, August 1999.

2. Gyozo Kmethy, “Meter data exchange – standardisation for interoperability”, Smart Energy International, issue 3, 2000, pp. 34-37.

3. Syllabus for the seminar “DLMS/COSEM: the ultimate data collection protocol for the liberalised energy market”, EnergieNed, Arnhem, 11 May 2000.