By Juan Brossa

From a long time ago mechanical meters have been the unquestionable leaders in energy measurement. They have fulfilled this function in a very scrupulous way with few technological advances. Their design was more typical of that from a watch making factory than a research department.

Finally, more than a decade ago, the long supremacy of mechanical meters began to be influenced by the new design of static meters. It was the first time after a long period of tradition that the mechanical solution turned to electronic technology.

From a technical perspective, in the first electronic meter designs there were no specific solutions for this type of device, so in most cases the experience of the engineer in knowing how to combine all the different components was the key point for a good design. The first step was the selection of the central processing unit, which is dedicated to managing all the external peripherals – analogue to digital converters, display controllers, data memory, communications, etc. Taking into consideration the significance of the worldwide meter market, most of the electronic components manufacturers have created a specific design line for this type of device, resulting in the opportunity of having all the functions mentioned in only one silicon chip, instead of combinations in a number of them. This has resulted in a significant reduction of the space needed on the printed circuit to assemble the electronic components. In addition the reliability is increased, because the total number of components of the design has been significantly reduced.

The most noteworthy point has been the introduction of new communications systems. Taking as a starting point the first meters with only a measurement capability, there was a small evolution when the optical interface was introduced. However, only with the advent of electronic meters were there innovative solutions and now it is possible to use wireless communications and also the electrical network as the physical medium to send and receive information. This change allows us to position the meter as a basic part of an energy management system instead of as an isolated device dedicated to measurement.

Energy management system

Energy management system

With reference to the mechanical design, over the past few years a lot of technical improvements have been introduced, such as plastic injection, which allows the option to inject several plastic pieces in a unique process, simplifying in a considerable way the assembly of the plastic parts of the meter and providing a more robust solution. With reference to the mechanical components, new options to develop more complex tools allow the integration of several mechanical functions in one solution, again simplifying the assembly process and improving the reliability of the product.

This technology evolution has been reinforced with the introduction of very important changes in the metering qualification process. Previously this was a very complex process, authorising a product in one place or in a local area, and then repeating the process across the whole country, and later to all the different countries in which it was decided to sell the meters. With the introduction of the MID, a unique approval process is provided for all the European Community countries, considerably simplifying the process. And it is very important to note that this normative is also a valid reference for many countries which are not part of the EC.

Circutor, with more than 35 years of expertise designing electronic devices, was one of the first companies worldwide to introduce in the market a very wide family of electronic meters. The main reason to justify Circutor’s decision to get into this market was the changing request for products, making necessary an evolution towards an electronic solution and the energy meter concept from a mechanical design. Circutor was able to contribute with its wide experience, based in its differential protection devices, network analysers and systems to compensate reactive energy.

Through a major design effort the R&D department of Circutor has applied many of the technological changes that have been discussed above to create a new range of meters, the Cirwatt type B family. These range from the basic single phase meter, able to be competitive in the most aggressive markets, up to advanced three phase meters able to communicate using the electrical network or using complex wireless technologies and with an internal power relay capability to cut remotely the energy supply to the end user.

This new family provides a technological evolution because innovative concepts have been applied to all the different parts of the meter. These include innovations associated to the electronic design, because of work with compact solutions that allow the provision of a very powerful calculation unit with the integration of all the necessary peripheral parts in a single chip, in this way providing a considerable reduction in device size and improvement of the quality of the product because of the reduced number of components. The mechanical parts have also been simplified and an attempt was made to minimise the number of components based on the use of multiple plastic injection techniques and the laser as the key system for final product labeling. All this design effort has been complemented with the introduction of important improvements in the manufacturing process, with the target to increase the production capability while maintaining the quality levels that are characteristics of Circutor’s products.

With the introduction of this new family, Circutor has overcome the challenge to introduce a technical evolution in the meter market, with the ability to offer a new range of products with high reliability and good technical behaviour, while remaining competitive.

This new meter range was developed not only to provide an answer to the real needs of the actual market, but in the future that they will be the key pieces in energy efficiency management. The problems associated to increasing energy consumption and its influence on the natural resources is well known. Thus it is not possible to talk about human development without talking about efficient energy management. Applying this to the meter world means developing devices capable to make as a first step passive management of the energy demand, with the target to make the user aware of their real consumption for any instant and the ecological cost to produce that energy. And a second step is the introduction of intelligent management of some loads in the domestic and industrial environments. In so doing the meter is converted from an element to measure to the most important part of an energy system.

Circutor, an energy efficiency leader, has defined a target to extend this concept to its full range of products. This direction is permitted by the state of the technology and the company believes that the evolution from mechanical to electronic meters has been only the first step towards energy management.