How Do Power Quality Analyzers Work?


Before you begin using your power quality analyzer, it’s important to learn how they work and what power quality issues they aim to discover. To get the most out of your device, it’s essential to learn the features and functions of the test equipment you are using. This is the only way you’ll be able to use the device to properly help you discover and pinpoint power quality issues. This article will help you understand the basics of power quality analysis and what power quality issues these devices can help you discover. When it comes to industrial applications, the benefits of these tools are vast, but nothing can replace the expertise of a trained and certified power quality specialist.

What is a Power Quality Analyzer?

Power quality analyzers measure voltage and current waveforms to determine whether they meet specifications. These devices use sensors to detect electrical disturbances such as spikes, sags, transients, harmonics, and noise. They also provide protection against equipment damage from surges, faults, and other electrical events.

The most common types of power quality analyzers are:

  • Multimeters
  • Oscilloscopes
  • Spectrum Analyzers
  • Digital Signal Processors

Multimeters– Multimeters are similar in appearance to an analog volt-ohm meter. They can measure AC or DC currents, voltages, resistance, capacitance, inductance, impedance, and many other parameters. A typical multimeter has three main functions:

  1. Voltage measurement
  2. Frequency measurement
  3. Resistance measurement

Oscilloscopes- An oscilloscope is a type of digital display that shows waveforms on its screen. It consists of two parts: a probe and a computer. An oscilloscope works by measuring the time it takes for a signal to travel from one point to another. This gives you information about the shape of the waveform as well as how fast it changes over time.

Spectrum Analyzers-  A spectrum analyzer is a special type of oscilloscope that displays the amplitude of a signal at different frequencies. You use a spectrum analyzer to analyze signals such as radio waves, microwaves, radar, television, audio, etc. By analyzing these signals, you can see what kind of interference they contain.

Digital Signal Processors- A DSP is a specialized processor designed specifically for processing digital data. A DSP can perform complex mathematical operations much faster than a general-purpose microprocessor. For example, a DSP could calculate the square root of a number using fewer steps than would be required with a regular CPU.


Why is power quality important?

Power quality is crucial because it affects equipment operation, safety, and reliability. If power quality is poor, then equipment may be damaged, causing downtime and increased maintenance costs. Poor power quality also increases the risk of fire, which can cause serious damage to property and the safety of the workers. 


Main power quality problems include:

Transient Overload– A transient overload occurs when the load on a circuit exceeds the capacity of the circuit for a short period of time. Transient overloads usually occur during peak demand periods such as late at night or early in the morning. The result is that some circuits may be overloaded while others are underloaded. This causes voltage fluctuations which can cause equipment damage.

Sags & Dips – Sags and dips in power are caused by the voltage fluctuation in the power supply. The sags and dips occur when the load current exceeds the maximum rating of the power supply. This causes the output voltage to drop below the minimum rated voltage. 

Harmonics Distortions– Harmonic distortions occur when the frequency components of the voltage waveform are out of phase with one another. This causes harmonics to be added to the fundamental frequency. The result is a distorted sine wave. 

Noise- is a high-frequency distortion of the voltage waveform caused by disturbances on the power grid or from equipment like switches or transformers. Undetected noise can cause equipment malfunction and early wear. 

Undervoltage- Undervoltage occurs when the voltage level of the power supply drops below what is needed for the device to operate properly. 


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About Advanced Power Quality, Inc.

Advanced Power Quality is an industry leader in power quality solutions with decades of combined experience. APQ offers power quality studies, analysis, field investigations, monitoring and advanced training to keep today’s engineers ready and equipped to handle the growing power quality challenges. 

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