Automatic meter reading devices introduced in the s were the beginning of meters which provided information back to the utility, a basic requirement of any smart grid system. The technology for monitoring sensors and relaying the data grew out of the caller-ID technology patented by Theodore Paraskevakos. All these technologies, and the more than one century of development, were necessary foundations for building the safer, more efficient, and more reliable electricity distribution network that will eventually become the smart grid.
Explore content Browse by Subject. Oral Histories. First Hand Histories. Special pages. Recent changes. User assistance Help. With this, the AC electricity system became feasible, and from the beginning of the 20th century it gradually took over from DC systems.
In metering, a new problem had to be solved — the measurement of AC electrical energy. In , the Italian Galileo Ferraris made the key discovery that two out-of-phase AC fields could make a solid armature like a disc or cylinder rotate.
Independently the Croatian-American Nikola Tesla also discovered the rotating electric field in Shallenberger also — by accident — discovered the effect of rotating fields in , and developed an AC ampere-hour meter. The braking torque was provided by a fan. This meter had no voltage element to take the power factor into account; therefore it was not suitable for use with motors.
These discoveries were the basis of induction motors, and opened the way to induction meters. The said phase displacement of phases results from the fact, that a field is produced by the main current, while the other field is excited by a coil of great self induction shunted from those points of the circuit between which the energy consumed is to be measured.
The magnetic fields, however, do not cross one another within the solid of revolution, as in the well known arrangement by Ferraris, but pass through different parts of the same, independent from one another. The meter used a brake magnet to ensure a wide measuring range and was equipped with a cyclometric register. Ganz started production in the same year. The first meters were mounted on a wooden base, running at revolutions per minute, and weighed 23 kg.
By , the weight was reduced to 2. Oliver Blackburn Shallenberger developed an induction type watthour meter for Westinghouse in It had the current and voltage coils located on opposite sides of the disc, and two permanent magnets damping the same disc. It was also large and heavy, weighing 41 pounds. It had a drum-type register. The rotor was a spirally slotted cylinder positioned in the fields of the voltage and current coils.
A disk riveted to the bottom of the cylinder was used for braking with a permanent magnet. There was no power factor adjustment. In the following years, many improvements were achieved: reduction of weight and dimensions, extension of the load range, compensation of changes of power factor, voltage and temperature, elimination of friction by replacing pivot bearings by ball bearings and then by doublejewel bearings and magnetic bearings, and improving longterm stability by better brake magnets and eliminating oil from the bearing and the register.
By the turn of the century, three-phase induction meters were developed using two or three measurement systems arranged on one, two or three disks. Paris Agreement. Smeaton also points out that there is currently no watchdog body keeping an eye on the smart meter issue in the UK. This would have shown his PLC system in action, along with others, to generate healthy debate on, and greater awareness of, the smart meter issue.
The public need to become aware that they have been dramatically undersold when it comes to Smart Meters. Email address:. Sign in Join. Sign in. Log into your account. Our Privacy Policy. Please Enter Promo code. We just need a few details so that we can find your account:. Payment Amount. Suggested Minimum Payment. Credit Card Number. Zip Code of Card.
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