Power Quality Analyzer: What is it?

The energy analyzer is a tool capable of measuring, recording, and identifying phenomena that affect energy quality, providing the user with all the information necessary for an accurate diagnosis of the measured electrical system.

It is also commonly called a recorder, however, it is important to always evaluate the technical characteristics of each model, so that through application and capacity, the user can identify the appropriate equipment.

The analysis software is an integral part of the tool, as it allows the user to properly process the recorded information, thus generating a report or a direct diagnosis of the object of the analysis. 

What is an Energy Quality Analyzer for?

Considered one of the most complex areas of engineering due to abstractions, modeling and dense mathematics (not to mention complicated), electrical engineering is what keeps almost everything in operation.

However , as in any other area, it is necessary to monitor, maintain, carry out measurements, which are like “medical examinations”, and solve problems.

There are countless problems and nonconformities that haunt engineers, technicians and everyone who uses and needs electricity to live or operate. Let's look at some of them below:

Power quality problems

• Power outage or “blackout”;

• Voltage outside the limits, absence of a phase, or the so-called “power outage”;

• Burning of loads, equipment, lamps and household appliances due to a voltage surge or even an atmospheric discharge;

• Poor sizing of protection circuits;

• System expansion and load increase without adequate retrofit;

• Disturbances in waveforms generated by frequencies other than 60Hz, causing burnouts and crashes;

• Poor sizing or overloads in systems, transformers, etc.;

• Incorrect power factor correction, or poorly applied systems.
  

We could list countless problems here, however, the important thing is to understand that problems with energy quality are like “illnesses” or “injuries” that can be analyzed, diagnosed and solved with a tool suitable for this purpose.

Imagine that you feel very tired (you have a power outage or are overloaded), or that you have a headache that stays there all the time (harmonics in the network), or that you faint (interruption)... We can make several analogies, but the main one is that, to solve the problems, it is essential that exams, or rather, analyses and measurements are carried out.

Just as a doctor needs an X-ray or a CT scan to define a diagnosis, the electrical engineer, technician, or consultant needs adequate tools to know what to do and what measures to take.

Analyzing curves, oscillographs, graphs, and other forms of presenting measurement results are essential to being assertive in the diagnosis.

Difference between energy logger and energy analyzer

An energy logger is a device capable of measuring and recording electrical quantities in general, such as: voltage, current, power, consumption, demand, among other basic ones. Imagine a “multimeter”, but with more measured quantities and with greater storage capacity (memory).

An energy analyzer is still an energy recorder (after all, it also records energy), since it stores all this information, but it has technology and hardware capable of recording much more complex phenomena, which require much higher processing capacity. So we define, informally, a difference.

 To illustrate, we can talk in terms of memory and sampling, considering the ranges of the vast majority of equipment available on the market:

	Memória	Amostragem por ciclo
Analyzers	Between 2GB to 16GB	Between 128 to 1024 samples
Registrars	Between 16MB to 2GB	Between 96 to 256 samples

The differences do not end here, as we have differences in terms of integration (time recordings), interface, treatment software, among several other factors. We can therefore summarize, roughly, that analyzers are advanced analysis tools, such as a CT scanner or an MRI, for example, while recorders are more common tools such as a blood pressure monitor or stethoscope.

Don't forget that I am basing this on market nomenclature, however, this is an informal name/definition. Therefore, it is very easy to get confused, and there is no crime in that. The person writing to you calls a photocopy a XEROX, and everyone understands that. Finally, I would like to emphasize the need to assess the TECHNICAL CHARACTERISTICS of each piece of equipment. For each problem or nonconformity, one may be more suitable than the other. 

Importance  and purpose of an energy analyzer

There is no way to perform a report or an analysis of power quality for any reason without a data collection. An analysis can be performed in a few minutes, hours, days, months or years, so the amount of information to be analyzed can be very difficult to assess without the right tool.

 Data collection, or recording, is the first step in analysis, and when we talk about Power Quality , it is practically impossible to collect data without an analyzer.

Let's look at a hypothetical situation for example:

Transformer with  high temperature

It was found through a thermographic measurement that the transformer is operating at a temperature much higher than that specified by the manufacturer. When measuring the current, it is not clear that there is an overload because there is still capacity to work. So, what should we do? In this hypothetical situation, an analysis of the k factor may be necessary, for example.

What is K factor?

The “K” factor is a constant that indicates the transformer’s capacity to supply non-linear loads (for example: induction furnaces, motor speed variators, rectifiers, inverters, no-breaks, etc.) and withstand harmonic currents without exceeding its operating temperature.

So to know the k factor, we need to know about harmonic currents. But how do we measure them?

Harmonics are frequencies that are multiples of the fundamental frequency (60HZ), which operate throughout the system, disturbing our ideal sinusoidal waveform.

If we consider the measurement of the first 41 odd harmonic orders, we have 41×60 frequencies to be measured, with their respective integration intervals in an analysis of at least 1 week. We are talking about hundreds of thousands of records.

But let's say that with great intention you collected 1 week of records for each frequency. Now comes the calculation part! Good luck with the Fourier Transforms and filtering and mitigation techniques! It is possible that this analysis, if possible, will take a few months to be performed. By then, the transformer may have burned out, or the client's patience may have run out.

It is not possible to perform complete Power Quality analyses quickly, with various simultaneous phenomena and events, without a power quality analyzer. The analyzer is an essential tool for engineers, technicians, electricians, companies, dealerships and teams that deal with electricity.

There are different models of power quality analyzers, for different applications, with different investments and we will dedicate a specific article to this.

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Below, in the link, see the main models and their applications .