Building A Smarter Meter
The move to smart energy brings massive opportunity across the supply chain but choosing the right solution needs careful consideration at every level, says ByteSnap Design Director Dunstan Power.As c
Measuring energy usage isn’t fundamentally difficult but creating a robust infrastructure around smart energy requires many elements to come together. The underlying technology is developing rapidly to enable the smart grid and the physical devices put in place over the next three to five years will need to remain in operation for many more; up to 20 years and possibly longer.
Against today’s fast moving technological landscape it would be difficult to imagine many electronic devices that would stand that test of time but smart energy measurement and control solutions have to meet this challenge.
Trends within the industry strongly indicate that wireless communication between energy aware devices promises the most viable solution in terms of longevity and functionality. And this is reflected in the efforts of the ZigBee Alliance which has worked co-operatively to develop the ZigBee Smart Energy Standard, now widely trialled by utility providers around the world in preparation for large scale roll-out.
As this roll-out begins, demand will rise for systems that implement the Smart Energy Standard. In parallel to ZigBee certification, these solutions will also need to meet the commercial requirements of a competitive market. To address these needs ByteSnap Design has developed and launched the industry’s first ZigBee Smart Energy module which integrates metering and control functions in a single, ZigBee compliant platform.
ZMM-01 provides a pre-integrated and pre-certified solution targeting OEMs and system integrators looking for a cost-effective solution to implementing a smart energy solution based on the ZigBee Smart Energy Standard. Using industry leading discrete solutions from Ember and Cirrus Logic, ZMM-01 enables system integrators to bring solutions to market much more quickly and with significantly less development expenditure.
Creating a robust wireless connection is inherently difficult and gaining compliance testing for a wireless device can be both expensive and time consuming. The ZMM-01 removes this pressure by delivering a fully integrated and compliant platform on which to build smart energy solutions. By implementing metering and control functionality on a single module, system integrators are able to target a range of applications where the ZigBee Smart Energy protocol will be used.
The modular design overcomes two significant development challenges; developing a rugged analogue front end, AFE, for measuring mains levels of voltage and current with creating a reliable radio interface implemented using the ZigBee protocol over the underlying IEEE 802.15.4 layer.
The AFE is a Watt/hour meter on a chip, developed with smart energy metering in mind. The AFE accepts two current and two voltage inputs, with an energy linearity of ±0.1% of reading over 1000:1 dynamic range. RMS voltage and current calculations are made on-chip, giving active, reactive and apparent power/energy data with system level calibration and phase compensation. The device meets the IEC, ANSI and JIS accuracy specifications and also provides voltage tamper correction and a power supply monitoring function.
Based on the Arm Cortex-M3 core, the ZigBee SoC from Ember delivers ample processing power and memory bandwidth for the implementation of customer specific applications. Bespoke customisation is enabled though ByteSnap’s ZDM-01 development kit which provides the perfect development platform for end products based on the ZMM-01 module. It includes an optically isolated USB serial port as well as a mains load simulator, giving the ability to vary the current, voltage and phase angle without working with the mains.
Energy measurement and control are intimately linked functions of the smart energy concept: ZMM-01 is the only solution that successfully combines both in a cost-effective, low power platform, says ByteSnap. The potential for smart energy measurement combined with control is only just being explored and as such, ZMM-01 is at the sharp end of integration, providing a flexible wireless platform that can be configured to meet today’s requirements whilst providing the required reliability and robustness to remain in service for many years to come.