Smart Gas Meters: Technologies and Challenges
Transcript of Smart Gas Meters: Technologies and Challenges
Smart Gas Meters:
Technologies & ChallengesDr. R S Shekhawat,
New Products Development
(Gas Metering)
Secure Meters Ltd.
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ContentsMechanical meters and associated problems
What is ‘smart’ device?
Embedding smartness in meters
– The desired functionality of smart meters
– The design attributes enabling smartness
– How different flow metering technologies enable these features?
– The race/compromise of different functionality/features for optimal
product
Communication sub-systems
– ZigBee and associated SEP x.y
– Sub-GHz RF
– Bluetooth
– WiFi (futuristic)
Benefits
– The consumer
– Utility/DistributorSmart Ultrasonic
Gas Flow Meter
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Mechanical meters and associated
problemsIndia domestic installation base consists of diaphragm
meters
These are predominantly based on mechanical
measurement and are prone to various drawbacks
associated with it namely Accuracy degradation over period of time- Mechanical parts
Manual reading – No smart billing options like prepayment
No AMR functionality- No i/o’s and modules provisions
Prone to tampers- tilt , bypass, etc
There are two solutions to approach the above problem
which is practiced worldwide namely Retrofit mechanical meter with electronic interface
Electronic measurement based on emerging technologies
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Smartness
Oxford dictionary:
(Of a device) programmed so as to be capable of some
independent action.
• Example: Smart Transmitters have capability of:
– Configuration
– Re-ranging/auto-calibration
– Standalone/independent [communication]
– Signal conditioning
– Self-diagnosis
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Benefits derived out of its’ smartness
Ease of installation and communication,
Self-diagnosis,
improved readability and reliability.
Less subject to effects of temperature and humidity than
analog devices.
although vibration can still affect them, the effects are far
less than with analog devices.
Smart [transmitters] also provide increased accuracy.
And because can replace several different types of
devices, using them allows for inventory reduction.
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The desired behaviour of a Smart [Gas]
MeterRecord the consumption with best possible accuracy
Report energy consumption at any interval & on
excessive consumption
Elicit behavior of consumption patterns
Correlate consumption rates with appliances in house
Govern consumption by set limits (prepay mode)
Raise alerts/alarms for tampers
Remotely readable and controllable (tariff and supply)
Improved revenue collection with lower overheads
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Design attributes for smart functionality
Convert consumption in digital values, store & display
(The conversion must be high resolution (few ml))
Have good local amount of memory for local storage
(upto a month)
Flag/log different type of events (e.g. excess usage)
Event-driven communications with minimum delay
Inbuilt self diagnosis
Auto-calibration
Stop/resume flow switch
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Hybrid Smart Gas Flow Meters
Measurement still using mechanical elements
(diaphragms etc)
Compensation of errors easier (combination of gears
and electronically computed)
Coupling of mechanical index using magnetic or
magneto-optical
Degradation effects still persist: diaphragm material
shrinkage, gear train wear and tear, and thus need
recalibration after 5-7 years
Bigger in size & weight
Usually Noisy
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Electronic - Ultrasonic
Inherently electronic measurements (transit time or
frequency method)
Natural interface to electronic systems
Wide dynamic range
Easier calibration (in-built)
Small in size and thus much lighter
Longer life (no moving parts)
Differentiation between NG & air
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Electronic – Thermal
Very low starting flow (4 LPH)
Noise-less and wear free
Compact design
Differentiation between NG & air
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Electronic – Charge flow
Highly accurate
Minimal signal processing
Low power
Small in size
Gamma ray source containment is an issue
Heavy due to shielding of radiation
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Communication systems (Home Area
Network)
Wired or wireless
Metering Bus (Mbus)
ZWave
Bluetooth
ZigBee
Wi-Fi
GSM/GPRS
Mesh Radio
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