In the last several years, the electric meter market has evolved in some significant ways. For example, utilities have increased their focus on maintaining the overall health of grid transmission and distribution networks. In turn, they are asking meter manufacturers to measure new parameters related to detecting fault conditions, monitoring power quality and identifying loads that can cause disturbances or outages on the grid. A partial list of new parameters includes peak voltage, peak current, zero-crossing detection and harmonic content. The need for measuring more harmonic content is driving up bandwidth requirements and compute resources needed for metrology. Other important trends are the need to directly measure neutral current channel in order to avoid electricity theft and meter tampering.
Electric utilities worldwide are aggressively rolling out smart meters with a wide range of communications technologies: PLC/RF, narrow/wide bandwidths and mesh/star topologies. Irrespective of chosen technology, all smart meter networks bring unique challenges. Utilities will deploy millions of meters, often in locations that have very poor signal conditions, and they expect 100% network coverage of all meters.
Meter communications systems operate in extremely noisy and increasingly crowded spectrum. Unlicensed RF bands are particularly challenging with no ability to control noisy neighboring networks. PLC networks face similar challenges with a wide variety of noise sources on the power line. In both networks, the spectrum becomes increasingly crowded as more meters are deployed. Successful deployment depends on cost driven components designed specifically for these unique challenges. Network robustness will depend on providing optimal link margin with devices with high sensitivity. In addition these systems must be designed with excellent interferer and adjacent channel blocking performance.
Utilities expect decades of useful life from their meters and networks. Flexibility to anticipate future requirements is therefore critical to the architecture and system specifications. These future requirements span new interference sources, new communications standards and new utility applications. In addition, with unique country requirements, no one design can meet all worldwide requirements. To reduce the effort to create multiple solution, smart meter communications engineers need a family of components that enable highly integrated or highly modular designs. This includes processor solutions spanning low power microcontrollers to cost optimized DSP's, standalone RF transceivers to single chip RF-SOC's, and discrete converters and amplifiers to full PLC modules.