This is the very third episode of the blog series we hope it will shed some light on energy efficiency, more specifically, on the efficiency of electrical equipment. So, if you are a maintenance/building/production manager, this one’s for you. If (and only if) you want to lower energy usage and costs, of course.

In the first episode we talked about what Power Quality is, we defined particular Power Quality Indices, and more. Find them out right here. In the second one, we talked about B-B-B-B-Bad Power Quality and its negative effects. Right now, we’re gonna talk about Power Quality Measurement. Let’s!

How do you measure Power…Quality?

Oh, well, Power Quality cannot be measured. As per se. What can be measured and we measure are various intermediary values. They describe the current and voltage waveform like their RMS value, their half period RMS values and their lag/lead angle. Based on these values, Power Quality Indices are then determined. Not just in any way, but the hard way - by complex calculations.

The measured values have a measurement frequency sometimes lower than 1 data point per second. We should right about now tell you that up to 232 data points/second are needed for some of the more complex Power Quality Indices. So, a simple energy meter cannot provide us with the required information. So, it cannot be used to determine/analyze the relevant Power Quality Indices. What now?

The tools

In view of the above, when doing Power Quality measurements specialized devices must be used. These devices are intuitively called Power Quality Analyzers, and they are either fixed or mobile systems. Their price ranges from 700 EUR - for the fixed, low-end versions, up to 6,000 EUR - for the mobile, high end versions. Yes, we know!

Who should do it?

The measurement should be conducted by authorized electricians, as they require installing complicated devices in exposed and energized circuits. As for the Power Quality Analysis, it is usually conducted by electrical engineers which are often also authorized as Energy Auditors. So, authorized personnel only.

Or

The Power Quality Analysis process could be automated. How? By using dedicated, fixed devices and advanced software solutions. Thus, every end-user can do it by himself, without being exposed to health and safety risks, whilst also minimizing the associated costs. Automation is the best answer.

Playing hard to implement

The prices are currently making Power Quality Analysis a process that is hard to implement in real-time. There are not many energy boundaries which are permanently monitored from this point of view, and the few ones that have fixed Power Quality Analyzers only do so in the Point of Common Coupling (PCC) - for example, on the secondary winding of the Power Transformer which supplies the energy boundary.

What does this mean?

This means that the Power Quality Analysis is not properly conducted (if it even is conducted) and the disadvantages that are generated by bad values of Power Quality Indices are not identified and, implicitly, are not mitigated. That’s bad. Very bad. But it can be good. Very good.

But about this in another episode (in another year, the next one, which is not so far, far away). Stay tuned and follow us for more energy stuff.