The traditional power utility's electrical network moves vast amounts of energy from power stations to a large number of customers (consumers). In essence, a power plant consists of a centralized control, the mechanism for one-way flows of power, and passive networks.
This classic view of the power grid is passing into history. On the energy net, there will be not only more lines, circuit breakers, and transformers, but also electronics, information, and communication protocols. The smart meter provides the way to get information regarding load usage into the communications channel. From there, the information is sent back to the power utilities' generation and control centers.
One of the main drivers pushing this development is the goal that by 2020, greenhouse gas emissions will have been reduced by 20% compared to 1990 levels, energy efficiency will increase by 20%, and 20% of electricity will come from from renewable sources. So the smart grids are the future of electronics and communications. Here we provide a tutorial for the design and the implementation of the smart meter portion of the smart grid.
The trend for smart grid systems management in the industry is to integrate a complete smart-meter System-on-Chip (SoC) that combines precision metering with a flexible and programmable processing. In addition, there should be Power Line Communication (PLC) subsystems to safely and effectively couple data onto the power line. With care, the power line can carry data along with power. Finally, provisions should be in place for advanced security methods for the transfer of data. With care, it should be possible to put all of this functionality in a single device.
The goal of a smart meter system is real-time control and adaptability of the grid, integration of decentralized generation from renewable energy sources, and support for multiple communication standards. These standards have to be secured by physical routers and by software firewalls such as, for example, the encryption of the communication. The information about energy flow in the smart grid cells has to be reliable and secure to avoid energy wastage and guarantee an end-to-end optimized management of the energy.
The SoC for smart grid is a device that integrates a programmable PLC modem. It contains a high-performance application core and metrology functions (see Figure 1).
The typical architecture is composed of a primary digital core , a secondary digital core and a metrology sub-system .
In part 2, we will examine each of these sections to see what they do and consider accuracy requirements.