RF & Wireless

AMR/Smart Grid

With a smart meter the reading process is fully automatic and continuous

In metering we are generally concerned with electricity meters, gas meters, heat meters and water meters. When an energy meter is read automatically, we talk about Automated Meter Reading (AMR) or smart metering. Until now, the meter reading has been purely manual, either by the customer or, labour-intensive, by employees of the provider.
With a smart meter the reading process is fully automatic and continuous. This is not only efficient but also allows a continuous recording of the consumption over very short-time intervals, for example, once a day, instead of once a year. Smart Metering is the first step required in the context of smart grids to bring communication into households. In the European Union by 2020 a total of 80% of all domestic connections should have a smart meter, although it now looks as though this schedule will probably not be upheld. For example, Germany will most probably reach the 80% mark only in 2022. For AMR, it seems that the Wireless M-Bus for communication between the meter and the data collector, which will then handle the direct communication with the energy suppliers, will become the adopted standard in Europe. The latter communication is usually via the Internet. It may be either wired via DSL or broadband cable or wireless according to various mobile radio standards appropriate to the data such as EDGE, GPRS or LTE. While transceivers for the wireless M-Bus in Southern Europe operate at frequencies around 169 MHz, in other European countries the frequency range around 868 MHz is used for the Wireless M-Bus. In other countries such as England, the systems use frequencies in the 2.4 GHz area, where, for physical reasons, the range of 2.4 GHz systems in buildings is very limited. 

PV: Photovoltaics

Photovoltaic Micro Inverter Safety disconnect is using wireless connection between modules and Data concentrator

Solar cells convert solar power into direct current (DC) and a converter then converts this into the appropriate sinusoidal alternating voltage or the alternating current (AC) of the connected power network. Wireless communication is available for data networking of the modules, this allows detailed data on the electricity generation to be passed on and evaluated. Often it is sufficient, however, to connect the converter via WLAN, Bluetooth or ZigBee to a tablet or a PC in order to obtain a detailed analysis of the electricity generation over a certain period of time.

Wireless M-bus

Wireless version of Mbus standard covered by innovative three wire connections using EBV chip Hermes

With its ‘Hermes’ chip, EBV Elektronik has brought a monolithically integrated component for M-Bus communication to the market that requires very little power for its operation, but nevertheless has a high driving load. The IC actively supports a low-power mode, which is very efficient especially for wireless M-Bus applications. Energy suppliers are currently experimenting with many different methods for collecting consumption data. However, the most convenient method is likely to be reading through an Internet gateway. Smart-grid technology ensures that electricity networks are no longer strictly uni-directional but operate flexibly; smart grids also bring the communication into the house. As an intelligent network, the smart grid, allows flexible control of power flow, in which the inclusion of the energy consumer plays an important role, since consumers will also be able to control the smart grid in the future. Thus, for example, a refrigerator can be controlled via a smart grid in such a way that it cools more strongly in order not to place additional load on the network in the high-consumption hours of the morning. In this way, a well-insulated freezer can shift most of its cooling activity (and therefore its consumption of electricity from the public grid) to the periods of low consumption. Whether a dishwasher begins its rinsing at 10 pm or at 3 am, is irrelevant to the consumer, because the latter only wants to put away dishes that are reliably washed and dried at a suitable time by the following morning. Depending on the network load, a smart grid can control an intelligent dishwasher so that it completes its work at an optimal time when the cheapest electricity tariff also applies. Smart grids can only be realised in the first place with appropriate communication between all parties involved, and it is here that communication via radio links comes into play. In particular, the communication of terminal devices such as refrigerators, freezers, dishwashers, etc., with a central unit should preferably be via wireless systems, among which ZigBee is a prime candidate, operating in the 2.4 GHz area. The central smart-grid interface within a residential unit can communicate wireless with the power grid.