{"id":509,"date":"2015-01-29T05:00:06","date_gmt":"2015-01-29T05:00:06","guid":{"rendered":"https:\/\/wireless-telemetry.com\/blog\/?p=509"},"modified":"2015-01-29T05:00:06","modified_gmt":"2015-01-29T05:00:06","slug":"introducing-vfd-energy-analytics-for-telemetry-scada-and-control-systems-part-2-of-3","status":"publish","type":"post","link":"https:\/\/wireless-telemetry.com\/blog\/?p=509","title":{"rendered":"Introducing VFD & Energy Analytics for Telemetry, SCADA, and Control Systems \u2014 Part 2 of 3"},"content":{"rendered":"

Jim Mimlitz, NRI<\/p><\/div>Yesterday, in Part 1<\/a> of this series, we reported that a recent pump station upgrade\u00a0resulted in\u00a0a staggering\u00a0energy cost reduction\u00a0\u2014 reducing the average electricity charges from $345\/month to less than $114\/month!\u00a0 Since you have kindly returned today for Part 2, your consideration will be repaid with the details of how this feat was accomplished\u00a0\u2014 and how this new technology may be applied to benefit your water\/wastewater utility, as well.<\/p>\n

Key to\u00a0Energy Efficiency: Reduction of Friction Losses<\/strong><\/h3>\n

In order to explain the pump station energy savings, let’s return to the automobile analogy.\u00a0Why does an automobile\u00a0achieve better gas mileage at moderate speeds than high speeds?\u00a0Isn’t it possible to just introduce a few higher gear ratios (6th gear… 7th gear)\u00a0so that the engine maintains the same RPM’s and MPG fuel consumption at higher speeds?\u00a0 The answer is\u00a0NO\u00a0\u2014 and the reason\u00a0is rooted in\u00a0friction or “drag”<\/a>.\u00a0\u00a0Because drag\u00a0force increases as the square<\/em> of the speed (and drag\u00a0power increases as the cube<\/em> of speed),\u00a0cutting the speed in half, for example,\u00a0decreases friction force by a factor of four (and decreases friction\u00a0power by a factor of 8).<\/p>\n

Keep in mind, though, that cutting the speed in half would require the car to run twice as long at 1\/8 power\u00a0\u2014 so the friction losses decrease overall by a\u00a0factor-of-4.<\/p>\n

In a water distribution system,\u00a0drag losses\u00a0mainly occur between the flowing water and the inner pipeline surfaces, but the same principle applies: drag force increases as the flow velocity squared.\u00a0 For example, cutting the pump flow rate in half will reduce accumulated\u00a0friction losses by a factor of four.\u00a0 It is here\u00a0\u2014 the reduction of friction losses\u00a0\u2014\u00a0where substantial energy savings may be hiding within a water utility\u00a0\u2014\u00a0and waiting to be discovered.<\/p>\n

\"Friction<\/a>

Friction Losses Increase as the Square of the Velocity.<\/p><\/div>\n

VFD’s and Pump Speed Control<\/strong><\/h3>\n

In order to control the flow velocity, the pump speed must be controlled with a\u00a0VFD\u00a0\u2014 a Variable Frequency Drive.\u00a0 And what is a VFD?\u00a0It is\u00a0a type of motor controller that varies the frequency and voltage supplied to the electric motor. Other names for a VFD are variable speed drive, adjustable speed drive, adjustable frequency drive, AC drive, microdrive, and inverter. In pump station applications, VFDs can be used to provide variable-speed pumping operation, as well as to provide slow ramp-up starts and slow ramp-down stops. If you are interested in reading a more in-depth explanation of VFD technology, please visit the wikipedia reference:<\/p>\n

http:\/\/en.wikipedia.org\/wiki\/Variable-frequency_drive<\/a><\/p>\n

Innovative VFD \/ Telemetry Integration<\/strong><\/h3>\n

Over the past 19+ years at NRI, we have developed innovative VFD\/Telemetry integration techniques through dozens and dozens of variable-speed pumping projects.\u00a0In the process, our techniques have pushed the state-of-the-art in Rural and Municipal Water control technology. We have helped water utilities:<\/p>\n