Intelligent Motor Controller

My first thought would be speed or rpm.

A motor can be set up with a tachometer which measures rotational speed and sends a correction signal to a variable frequency drive. Other systems use a servo motor with an encoder and servo drive.

Note: this is not new. Allen-Bradley has their Smart Motor Controller (which is a soft-starter, not a variable frequency drive). Smart/Intelligent just means that it probably has a microprocessor.

Another technology is phase-correction. The phase difference between a motor's voltage and current increases as the load decreases. What this device does is to reduce the difference at any load. How it does this is going to take more space (and typing) than I care to do, I'm sorry to say.

Note: this is also not new. The first time I heard about it was in 1984, more than 20 years ago.

Last note: the devices I just described do not do "anticipation". The speed or phase-difference has to change before the controller makes a correction.

Hees,

I don't know the particular device you are talking about, but this sounds too much like one of Dennis Lee's gimmicks. (Be Free Technology).

http://www.befreetech.com/feinfo.htm

A report of his motor "controller":

"He suggests that motors get hot because of planned obsolescence. Basically, he says, the power company sends more power than the motor needs, and the motor company uses that to make the motor hot and eventually break down. He says he builds a device that will measure the current a motor draws, and lowers it to that exact point to run the motor without it getting hot."

Taken from this site of exposes:

http://www.randi.org/jr/112301.html

On the other hand there are devices that can save some power in certain circumstances on "household" motors as you describe, but without "anticipation". The kind I am familiar with, is only for single phase induction motors that are relatively inefficient and/or lightly loaded, and in most cases only the 4 pole (1725 rpm at 60 Hz, or 1440 rpm at 50 Hz) variety. Of course the advertising hype doesn't mention all the limitations, only the very optimistic "Saves up to ......", which represents their absolute best case.

There are new things all the time, but there are many scams out there, and even when something like this works, the payback is questionable.

For larger industrial motors there are a variety of devices that can save some energy, but even then whether they actually pay for themselves is based on the specifics of a given installation.

If it isn't a name brand, investigate thoroughly.

Greg

Dennis Lee: "He suggests that motors get hot because of planned obsolescence. Basically, he says, the power company sends more power than the motor needs, and the motor company uses that to make the motor hot and eventually break down. He says he builds a device that will measure the current a motor draws, and lowers it to that exact point to run the motor without it getting hot."

I am regularly (unfortunately) amazed by "geniuses" lack of understanding of electricity! I wonder if he thinks that a 10 HP motor will use (and waste) all 10 horses of its power when running with no load . . . ?

Intelligent motor controllers have been around for a long time, and they have reduced operating costs for industries worldwide.

Anticipation is not necessary in the big scheme of things. Measurement of operating conditions and figuring out what's needed is relatively easy.

Let's use an HVAC system for an example. In the old days, a large HVAC system may have been designed with a constant speed blower and either dumping hot or cold air somewhere other than into rooms where zone thermostats are satisfied. Of course, this hot or cold air took energy to make it that way, and dumping it wastes energy. Additionally, some of that hot or cold air may have been useful in other parts of the building, but system design didn't allow for diversion to places where it could have been used.

By monitoring building conditions, duct damper and fan speed controls can be used effectively to control building comfort fairly much more efficiently. Multiply this 1000's of times over, and pretty soon, you've got yourself a pretty good worldwide energy savings.

Bill,

Good point about the variable speed possibility!

I was only assuming constant speed applications.

Greg

When the motor is running at partial load (assumed as cage induction motor)by redusing the voltage losses are reduced resulting in savings.There are many manufacturers making this .Power Boss Uk, Savawatt uk, web sites will give lot more info.China has a lot of manufacturers .

Just reducing the voltage is not the way these devices operate. They analyze the voltage and amperage and alter the wave form.

Low voltage by itself tends to make induction motors run hotter and less efficiently.

Greg

Depending on the type of motor or its application there is a number of ways

• Monitor the exact speed with devices such as Tachometers or optical pick-ups. then adjust the fuel or power to automattically keep the speed at an exact measurement.
• Monitor and adjust the firing point of a piston
• Monitor the phase difference or lag time
• in a power supply, digitize the analog signal and control the work period of a signal then re convert it to an analogue signal

The anticipation generally is only as a response to small changes, however, the phenominal speed of electronics compared to the real world of motors makes it seem instantaneous. (can you see a Microsecond)

Real anticipation can be done on a factory floor by using cameras or detectors to see when an object is arriving on a conveyor.

Most of these "intellegent" motor controllers are really just a scam to separate ignorant people from their money by appealing to their desire to save energy. The basic flaw in the entire concept is that ONLY ENERGY THAT IS WASTED CAN BE SAVED! In other words, if you have a motor running at 1/2 load, it is ALREADY saving a lot of energy compared to running at full load, because a motor uses primarily only the energy it needs to do the work! The only energy 'wasted" in any AC motor application is in the losses in the motor, not the load. So if you look carefully at AC motor specifications, they will show you the efficiencies at various load ratings, i.e. 80% at full load, 85% at 3/4 loaf, 86% at 1/2 load etc. What you will almost always see is the as the load goes down, the efficiency actually goes UP in a lot of cases. So even though the Nola circuit (the basis of ALL of these intellegent controller designs) does work to reduce the magnetization losses in a motor, those losses really only represent a very small fraction of the power being used at any given load percentage. What these scam artists do is to state the savings based on a percentage of Losses Saved, not a percentage of losses compared to running power.