Technical Report AERIUS and Smart Metering - diehl. · PDF filesmart meters to be used in virtually any ... sensors have been widely used for ... Technical Report_AERIUS and Smart

Diehl Gas Metering GmbH

Industriestraße 13 · 91522 Ansbach · Telefon +49 (981) 18 06 - 300 · Telefax +49 (981) 18 06 – 325

[email protected] · www.diehl-gas-metering.de

1

AERIUS – Smart Metering in gas consumption measurem ent Keywords: electronic gas meter, Smart Metering, Automatic Meter Reading, microthermal flow measurement Abstract Smart Metering will become increasingly important in the domestic segment in the near future – not only due to legal standards – and offer consumers more billing transparency. Hydrometer, a company that has shaped the market for water meters for over 150 years, is part of the Diehl Metering division set up in 2008. Diehl Metering is dedicated to supplying meters for all kinds of energy and is working intensively on the completion of a new static gas meter. Diehl Gas Metering GmbH in Ansbach, the company set up for this purpose, concentrates the gas metering expertise in the division and is developing the AERIUS G4 meter for households with a maximum flow rate of 6 m³/h. A whole product family is to be created in further development stages in the near future. AERIUS provides a temperature-compensated standard volume independent of pressure changes, which is an innovation in household gas measurement. Normally, gas meters use measuring methods in which the standard volume must first be calculated from the operating volume. However, the microthermal metering principle used by Diehl Gas Metering provides a standard volume that can be multiplied direct by the calorific value for billing. The possibility of integrating the meter into the IZAR system landscape offered by Diehl Metering creates a highly informative network for very accurate metering of heat, water, electricity and gas consumption. Diehl Gas Metering will present the AERIUS gas meter and the IZAR system landscape at the ZMP FNN Congress at NürnbergMesse on 23–24 May 2011. 1. Introduction The European Union’s new Energy Services Directive calls for appreciable savings in the use of precious reserves of raw materials in the coming years. These include gas as well as water, heat and electricity. With effect from 2011, consumers can request monthly billing from the utilities to obtain a prompt account of their consumption. This is intended as a basis for energy-optimized behaviour, which not only saves costs, but also spares resources in the long term. The prompt determination of consumption not only needs intelligent meters, so-called smart meters, but also a system that provides continuous data communication from the meter through to billing. As every system must be adapted to the existing local infrastructure and accommodate customer requirements, smart meters must be variable in terms of the communication modules equipped. A compact design and noise-free operation combined with accurate measurement of consumption enable smart meters to be used in virtually any installation location. Customer-friendly displays show consumers their energy consumption conveniently and create a high degree of billing transparency. Static equipment such as personal computers or mobile handheld equipment can be used for this purpose. Diehl Gas Metering is currently working on completion of the new AERIUS static gas meter for households, which is shown in Fig. 1 . The measuring principle of this meter is based on a microthermal method using the latest semiconductor sensors,

Technical Report first publication in gwf International Mai 2011

Irene Heidt Marketing Manager Diehl Gas Metering GmbH Industriestraße 13 91522 Ansbach Germany Tel. +49 981 1806-310 Fax +49 981 1806-325 E-mail: [email protected] Internet: www.diehl-gas-metering.de




2

which are produced on silicon wafers in a CMOS (Complementary Metal Oxide Semiconductor) process. These MEMS (Micro Electro Mechanical Systems) sensors have been widely used for years, not only in the industrial environment, but also in air conditioning, medical and automotive applications. The variable use of standard communication interfaces enables Diehl Gas Metering to present a gas meter that is not only smaller than conventional diaphragm gas meters, but also suitable for unrestricted use in Smart Metering applications. The meter can be supplied with all common interfaces, such as wired M-Bus or radio-based wireless M-Bus OMS®, according to the customer’s requirement. This means AERIUS can be integrated into an intelligent overall network for prompt and accurate recording of consumption, for example into Diehl Metering’s IZAR system. 2. Measuring principle of the AERIUS static gas met er Normally, gas consumption in households is measured by diaphragm gas meters. As this is a mechanical method of measuring, the signal must be converted from a mechanical to an electrical signal before it can be transferred. Diaphragm gas meters measure the operating volume. For billing purposes, the operating volume must be converted to a standard volume taking the pressure and temperature into consideration. Diaphragm gas meters are not usually equipped with temperature and pressure sensors, which means measurements of the operating volume contain uncertainties if only the mean annual pressure and temperature values are used. These uncertainties can be easily calculated via the general equation of states for ideal gases using the following definition

.constT

Vp =⋅

where p is the ambient pressure in mbar, V the volume measured in m³, and T the temperature in K. As natural gases can be regarded as ideal gases, this gives a volume measurement error of approx. 0.1 %/mbar pressure change and 0.37 %/K temperature change. The AERIUS static gas meter from Diehl Gas Metering is equipped with a microthermal flow sensor as measuring element for detecting gas consumption. As the gas temperature is measured at the same time by a temperature sensor integrated on the flow sensor and the measuring principle is independent of the pressure in the application range, this thermal method offers the possibility of measuring the standard volume. The standard volume can therefore be used directly for billing, without the need to first calculate it from the operating volume based on the altitude in metres and a mean temperature. This enables utilities to simplify the steps involved in processing meter data in the long term. For determining the gas consumption, the thermal flow sensor is equipped with a silicon compound membrane of a few micrometres thickness. A heating element comprising semiconducting silicon material and temperature sensors arranged symmetrically to the heating element across the direction of flow is embedded in the membrane. An electronic circuit integrated into the chip actuates the heating element briefly (<100 ms) so that the membrane is heated locally to a few Kelvin above the temperature of the gas. If no gas flows over the membrane, the temperature distribution is symmetrical in the direction of flow and in the opposite direction. The temperature sensors on the membrane then measure the same temperature and the difference between them is zero. If gas flows, additional heat is transferred from the membrane into the gas and causes the temperature distribution to change. It becomes cooler on the membrane in the opposite direction to flow upstream before the heater than in the direction of flow, i.e. downstream. This means that the two temperature sensors now measure different temperatures and a difference exists. The amount and sign of this difference




3

represent the measuring signal and provide information about the flow velocity and direction. Fig. 2 shows the principle of thermal flow measurement in diagrammatic form. Thermopiles of doped silicon and aluminium are used as temperature sensors. In addition to the measuring signal’s dependency on the flow velocity of the gas, the measuring principle is dependent on the type of gas. This dependency is based on the fact that transporting the heat from the membrane to the gas is also determined by the properties of the gas. To compensate for the dependency on the type of gas, AERIUS is equipped with a measurement mode that determines the gas type. This additional measurement is used to adjust the output signal in line with the type of gas. AERIUS can be used for natural gases of type H and conditioned biogases towards type H as per German DVGW Worksheet G260. The measurement mode offers the advantage of being able to distinguish between air and a natural gas. This makes it possible to detect air present in the gas pipe, which would indicate manipulation or a temporary de-installation. 3. IZAR system landscape for Smart Metering Intelligent meters for measuring consumption – smart meters – need communication interfaces for reading the current measurement data over long distances and transferring this data to an Automatic Meter Reading (AMR) system. As AERIUS already has an output signal in electronic form, this gas meter from Diehl Gas Metering can operate with all the usual standard interfaces. These interfaces enable the measured standard volume to be transferred to the utility or end consumer over wired or wireless interfaces. AERIUS will be supplied with the following interfaces:

• Wired M-Bus to EN 13757 Standard

• Wireless M-Bus to Open Metering Standard (OMS®)

• Optical infrared interface

Using these interfaces, AERIUS can be integrated into all AMR networks available on the market, such as METERUS, FNN-MUC or powerline systems. Diehl Metering offers a complete system landscape from one source, which can also incorporate AERIUS meters. The IZAR system not only reads individual meters, but creates a whole network that can be used for determining, transmitting and displaying all the necessary information about water, heat, electricity and gas consumption. The variable configuration of AERIUS with all common standard interfaces permits individual arrangements for reading gas consumption and adaptation to local factors. For example, mobile reading using the walk-by or drive-by mode is advisable if the consumption data must be available annually to quarterly. The data here is preferably transmitted over radio. This eliminates the need to lay additional cables, which avoids extra cost. In the walk-by mode, the data is recorded by mobile data acquisition devices like handhelds, PDAs or notebooks, which can record all the data using the IZAR@MOBILE software. To save time, the data can also be read in the drive-by mode, in which case all consumption data is recorded via a vehicle driving by at speeds of up to 50 km/h. The mobile IZAR system can be easily integrated into an existing fixed network. If monthly to daily reading is required, a radio fixed network or a cable fixed network is recommended. Permanently installed receivers collect the consumption data and forward this to




4

the utility for further data processing over a GPRS, LAN or WLAN link. Fig. 3 shows an example of a radio fixed network with all the necessary components for transferring consumption data for further processing. The values measured by the meter are sent to a GPRS receiver by radio using the OMS® standard. This forwards the data over GPRS to a central FTP web server at permanently defined upload intervals. The IZAR@NET software on a personal computer receives the transmitted and encrypted information from the web server, visualizes this and provides the data for further processing, for example, over an interface connection to billing systems.

IZAR@NET is an energy data management software used for automatic recording and secure transmission of all consumption data in an M-Bus or fixed radio network. Tours and data for mobile data acquisition using the walk-by or drive-by mode can also be planned and administered. IZAR@NET can be installed on any standard PC. If the network is expanded, only a software module needs to be installed. No changes are necessary if the reading method is modified, because IZAR@NET can request and process the data independent of the communication interface used. The data received by IZAR@NET is combined in a report by filters configured by the customer. This report is exported automatically in defined sequences to the utility’s database, data management system or billing system. Secure transmission and communication standards are assured by encryption of the data to DES (Data Encryption Standard) and transmission as per EN 13757, Mode T1. The integration of one of the largest database systems, ORACLE, which runs in the background of the AMR IZAR@NET software, offers a high standard of data security. The whole system can be backed up using customer-configurable back-up scenarios. In addition, double mirrored and encrypted web servers at different locations are used to avoid data loss in case of fire or other unexpected incidents and provide a high degree of data security. The IZAR system makes it clear that Smart Metering is not limited to intelligent meters, but must be regarded as a system landscape. A high degree of system flexibility is first created by the possibility of using variable interfaces at the meter. Other keywords are data security and extendibility of the system for creating an open system landscape to save costs and time. The IZAR system combines these points and offers the option of using a single software program as energy data management system for forwarding the data securely to both the consumers and the utilities for billing. 4. Summary and outlook The Diehl Metering division is currently working on the completion of a new static gas meter for the domestic segment. In order to meet customer requirements, Diehl Gas Metering GmbH has been set up in Ansbach as a centre of excellence for gas metering. The new AERIUS gas meter is based on a microthermal measuring principle. The heart of the meter is a semiconductor sensor produced in a CMOS process. As an electronic output signal is already available and the AERIUS meter is small (approx. half the size of a G4 diaphragm gas meter), it is particularly suitable for a Smart Metering system. AERIUS is equipped with standard interfaces according to customer requirements, either with a wired or wireless M-Bus protocol. As Smart Metering is not limited to intelligent meters, AERIUS can be integrated into all the usual AMR systems. If an open system landscape is used, e.g. Diehl Metering’s IZAR system, it is possible to set up a mobile network, a radio or cable fixed network. All the data collected, either mobile using the walk-by or drive-by mode or over the fixed network, is passed via secure FTP web servers to visualization and processing software, such as IZAR@NET. Customer-specific filters can be used for automatically sending reports to utilities’




5

billing systems. Here data security plays a major role in ensuring secure data transmission and avoiding the loss of data. Importance is also attached to using existing defined standards, whether for encrypting or processing the data. AERIUS will be equipped with unidirectional interfaces in the first phase, which will allow transmission of the data for the consumed gas volume and integration of the meter into an AMR system. AERIUS will be provided with bidirectional radio interfaces in a subsequent development phase. This will enable additional information to be transmitted to the gas meter, such as the calorific value of the natural gas, and an AMI system (Automated Metering Infrastructure) or even a Smart Grid Network can be set up. As AERIUS already provides a standard volume output, the knowledge of the calorific value will permit a direct display of energy consumption – and make AERIUS an energy meter. If the utility’s current tariff is also transmitted as further information, AERIUS can show a direct display of the energy costs incurred. Tariff rates can also be introduced without difficulty over the bidirectional radio link, which means that different tariffs can be used at certain times of the day. Upgrading AERIUS with bidirectional radio interfaces offers consumers greater billing transparency and increases their awareness of handling natural resources with even more care.

Characters: 15.659




6

Figures Fig. 1. AERIUS – the new smart gas meter from Diehl Gas Metering

Fig. 2. Principle of operation of microthermal flow measurement

Fig. 3. Transmission of consumption data over a radio fixed network

AERIUS

868 MHz GPRS TCP-IP

GPRS RECEIVER FTP WEB SERVER IZAR@NET




7

Fig. 4. Diehl Metering’s open system landscape IZAR for the integration of smart meters, data processing and transfer via IZAR@NET Authors Dr.-Ing. Christoph Sosna Research and Development Diehl Gas Metering GmbH Ansbach Tel. +49 981 1806 303 E-mail: [email protected] Dipl.-Phys. Ing. Manfred Schulze Member of Management Board Diehl Gas Metering GmbH Ansbach Tel. +49 981 1806 200 E-mail: [email protected]

Documents

Technical Report AERIUS and Smart Metering - diehl. · PDF filesmart meters to be used in virtually any ... sensors have been widely used for ... Technical Report_AERIUS and Smart