Voltage power optimisation?

[skip.delclos]

We are very familiar with most 'typical' power conditioning systems. However, we have come across one that uses 'voltage power optimisation' (UK-based company) and are unfamiliar with this. Basically, it deals with the discrepancy between the actual supply voltage you recieve (205v - 250v) and the optimum voltage your equipment needs (220v). They claim all of the same benefits that traditional power conditioners claim to achieve (reduced kWh, costs, reactive power, maintenance, etc.). They also state that this is designed for overvoltage conditions 'in the UK'. They do not mention anything about reduction in amperage, which seems odd. Are there benefits to this technology over traditional conditioners? Any potential negatives? What if the conditions do not involve overvoltage? Thanks

 

[charlie b]

Are they claiming that this thing will save the customer money on their electric bill? If so, I strongly suspect that it is a fraud.

 

[skip.delclos]

Charlie,

Thanks for your reply. Yes they are claiming reduced energy costs, up to 20%, which I agree is very suspect to say the least. We have delt with some 'honest' power conditioning people who sell the system as PQ enhancement and only a small (1-2%) savings in energy. That was one of a few red flags that hit us when we read about this product. Any other ideas on this voltage optimisation? Wouldn't reducing the voltage possibly result in overheating the motors? Thanks
Skip Delclos

 

[Jraef]

Sounds like someone I know but will not name in a public forum (they have threatened to sue me in the past, cost me $50 for a lawyer to write them a letter which shut them up).

Worthless claims in my humble opinion. These things are all based on the old Nola Circuit that's been around since the 1970's, despite their claim that it is not. It uses SCR phase angle control to reduce the voltage in a continuous manner (like a soft starter, but a soft starter ramps and finishes, this stays low). The basic concept of "voltage optimization" is twofold:
1) You can lower the voltage to a motor that is unloaded BECAUSE it is unloaded and therefore (presumably) does not need full torque, thus saving magnetizing energy, and
2) If you lower the voltage of a 3 phase system to the lowest of the 3 individual values, you eliminate negative sequence currents that increase losses in the motor.

Both situations are technically true, but in reality the problem is grossly over stated, the solution is problematic but they ignore the problems, and the "energy savings" numbers they claim are bordering on fraudulent because they are actually referring to saving a percentage of the WASTED ENERGY, not the USEFUL ENERGY consumption. But when you look at the numbers, a motor that is 95% efficient is not wasting 20% right? it's wasting 5%. So how are you going to save 20%? What they do is reduce the magnetizing energy losses by 20%, which accounts for about 40% of the iron losses, which are about 25% of the total losses in a motor which in the case of a modern energy efficient motor is about 5%. So their claim of 20% savings is really 20% of 40% of 25% of 5%. Do the math, it's next to nothing.

But they have lawyers at the ready to challenge anyone that says they slipped over the border of fraud. Their wording is VERY VERY carefully crafted.