智能仪表：AMR/AMI

For AMR (and AMI) to become truly pervasive it needs to provide more than a reduction in meter reading costs. Optimization for Asset tracking, dynamic pricing, tamper notification, outage management, supply automation, load profiling and network diagnostics are critical elements for the success of this infrastructure. This drives the move from Mechanical Meters towards Static (electronic) meters for all major utilities (Electricity, Water, Gas, Heat).

Currently, meters can be read manually, touch-read (handheld device with a wand or probe), Radio, Bus, Power Line, Modem, or GSM/Satellite. The drivers behind each choice are cost, existing infrastructure, and local regulations. In some regions the usage charge for a radio frequency band is higher than the cost of manual reading, or the local grid may not support communication over the power line (PLC).

In any case, the trend is towards AMR increases the electronics content of the meter itself, and AMI drives a networked infrastructure for all metering. A complete implementation could include power line communication to the electricity meter, and low power wireless communication from the electricity meter to other utility meters. Low power wireless communication to the major loads in the home/business (AC, Heaters, Refrigeration, etc) and would also allow dynamic setting control during power plant peak loading.

Given the need for very low power consumption, microcontrollers like the MSP430 are ideal for any metering application. An advanced electronic meter requires an MCU that offers precise measurements over a wide dynamic range, programmable Flash, non-volatile storage, real-time clock function, flexible display and AMR-enabled communications features. The MSP430 family offers up to up four 16-bit independent sigma-delta converters and programmable gain amplifiers along with specific integrated e-metering modules such as the ESP engine or 32x32 hardware multiplier allowing for easy, high performance metering calculations Utility Metering

TI’s F28x controller platform provides a cost-effective means to implement PLC technology. Along with advanced DSP cores, the controllers integrate robust peripherals such as analog-to-digital converters (ADCs), timers and pulse-width-modulation (PWM). F28x controllers offer a unique combination of 150 MIPS of 32-bit control-optimized performance, system integration and microcontroller- (MCU) like ease-of-use. This high level of system integration simplifies design and keeps control systems compact and cost-efficient. MCU-like instructions and on-chip flash memory enables rapid prototyping.

Range, network configuration and power consumption are important factors when selecting a Low Power Wireless (LPW)solution. Range is affected by output power, sensitivity and selectivity, which in turn impact the jamming of other signal sources and the ability to distinguish the desired signal from local interferers. Point to Point, Star or Mesh Network choices not only impact these elements, but also the standards and frequency ranges chosen. TI’s LPW/Chipcon product family offers the performance and flexibility needed for Metering AMR and AMI applications.

For the electricity meter, power for the electronics can be derived from the single to 3-phase power lines. For other utilities, the meter would either need to be attached to a power source or leverage an internal battery. In some regions it may also be possible to use rechargeable batteries and small solar cells to recharge them during the day. In order to do this effectively, high efficiency power and battery management devices are necessary.