PQ Definitions & Standardized Waveforms


Owning and operating transmission and distribution networks requires knowledge of power quality definitions and standardized disturbance waveforms. With utilities growing use of power quality monitoring, having engineers with knowledge of power quality and disturbances is a must when troubleshooting utility-related power quality problems. Learning the power quality definitions and technical jargon is one of the starting points when aiming to become a power quality engineer. Learning how to recognize some of the simpler disturbances while learning some of the definitions helps engineers begin to grasp the subject matter of power quality.

Every utility transmission and distribution network is unique. With technologies available from Electrotek and Dranetz, utilities can install a power quality monitor anywhere on their network. When a power quality problem surfaces which causes an interruption in their customers' business or manufacturing activities, utilities want to know the characteristics of the voltage and current as soon as possible. Voltage and current characteristics can be anything above and below a monitoring point. Numerical data doesn’t provide the engineer with nearly enough information about the problem; thus, the reason power quality monitoring instruments were developed.

Electrotek’s power quality digital library comprises a wealth of numerical and disturbance waveform data from many different utilities and power quality conditions characteristics of only utility operations. Gaining experience in being able to identify disturbances based on their shape and numerical data comes with experience. However, learning how to recognize waveforms including what’s going on with the voltage and current, regarding upstream utility equipment, downstream equipment, and/or loads provides is a very useful learning tool. Electrotek’s basic power quality training classes offer beginners basic knowledge regarding power quality definitions and standardized waveforms. Utility engineers can gain exposure to more complex disturbance waveforms through taking a series of classes in our advanced power quality training classes.

Architecture & Engineering Firms

Architects and engineers design and upgrade electrical systems for residential, commercial, and industrial facilities. Downstream of utility power systems, the behavior of customer power systems when powering non-linear electronic loads is quite different. Lower levels of energy are distributed and delivered to individual customer loads with non-linear, dynamic impedance characteristics. A&E firms don’t have near the experience in dealing with power quality and disturbance waveforms that Electrotek expert PQ engineers do. The objective for the A&E firm is to gather all of the technical information regarding the power quality problem and work with Electrotek if the problem is caused by a design issue with the customer’s electrical system. In the majority of cases, the PQ problem involves disturbances generated by operation of the customer's loads. Disturbances from the utility may also be related to the problem. Digesting all of this information, possibly combined with power quality monitoring data recorded by advanced Dranetz PQ monitor(s), will be helpful in determining what remedial actions are necessary to solve the customer's problem. Most of the involvement on the part of A&E firms is responding to the request of the customer and keeping them updated as Electrotek and the A&E firm focus on gathering and analyzing the information critical to understanding it.

A&E firms are increasingly faced with specifying the right type power quality monitoring equipment for a facility they’re designing. A&E firms and their customers are starting to realize that not all monitoring instruments and data analysis software are equal. The power quality data recorded by a monitor is only as good as the algorithms used to sense and capture the right type of data required to diagnose the problem. This is compounded by the quality of the data management and analysis software. Many PQ software platforms don't allow users to understand the software and are not very user friendly. Today's PQ problems require total flexibility in downloading PQ data from multiple monitors and performing various types of advanced analyses to determine the cause of the PQ problem. 

A&E firms may also be responsible for commissioning a new or renovated facility before the customer takes occupancy. Traditionally, commissioning a facility doesn’t involve power quality or making power quality measurements. Commissioning an electrical infrastructure and its loads in a facility consists of measuring voltages, and checking to see if power is available to all loads. Availability of power to loads is only the beginning of what is required to ensure proper operation of non-linear electronic equipment in customer facilities. However, if facility commissioning involved specific PQ-related tests on the wiring and grounding system and power quality monitoring with loads installed and operable, potential wiring- and grounding-related power quality problems could be identified and remedied before customers are allowed to take occupancy. Electrotek has developed specific test protocols to accomplish wiring and grounding tests with power quality monitoring in new and upgraded customer facilities. Our expert power quality engineers maintain the knowledge necessary to properly commission customer facilities as an effective proactive measure to avoid costly PQ problems.

Engineers responsible for addressing problems with customer electrical systems need to know power quality definitions and jargon and how to recognized disturbance waveforms. This knowledge will help engineers to communicate with their customers, and the electricians when dealing with potential power quality problems. Electrotek expert power quality engineers are trained to address potential power quality problems developing in new and renovated facilities before the cause costly production line downtime and expensive equipment repairs.

Equipment Manufacturers

Equipment manufacturers who engage in power quality monitoring to learn something about early product failures in their customers’ facilities should be able to understand power quality definitions and basic jargon, as well as, recognize basic power quality disturbance waveforms. Recognizing basic waveforms will allow them to engage in semi-technical discussions with Electrotek and their customers regarding the causes of equipment failure. Electrotek’s ability to identify the likely causes of failure by engaging in our forensic analysis service is an important step in pinpointing the actual cause of failure. The cause of failure can be incoming utility power quality disturbances, generation of disturbances by normal operation of non-linear electronic loads inside a customer facility, or inadequate power quality equipment immunity to common everyday disturbances. In the majority of cases, all three combine to significantly increase the rate of equipment failures.

A manufacturer’s customer or field service personnel will want to discuss the power quality data analysis report generated by Electrotek. Such discussions are important whether those reports resulted from monitoring carried out by the manufacturer or by Electrotek. The report combined with those discussions are typically transferred to the product engineering department. Electrotek often leads or participates in such discussions. This helps manufacturers understand how to incorporate report results into improving product designs to improve immunity to electrical disturbances. Manufacturers can also enroll in Electrotek’s basic power quality training to help them begin learning how to use power quality definitions and jargon, as well as recognize basic power quality disturbances. Advanced power quality training is also available from Electrotek on the more complex subjects of power quality, some of which manufacturers would benefit, depending upon the type of electrical and electronic equipment they sell and the types of PQ problems occurring in the field.

End Users

End users play a unique role in power quality as they are at the “end-of-the-line” with respect to disturbances—utility generated or generated by interactions between customer loads and their realistic wiring and grounding systems with deficiencies. Their patterns of use for their loads, maintenance (program and effectiveness) of their facility and electrical systems, and upkeep of their electrical and electronic loads are all critical factors that determine the rate of occurrence and severity of power quality problems. With one of Electrotek's core missions being helping customers to develop power quality basics and understand the front-end value of managing their own internal power quality, customers must the proactive step to learn and understand basic power quality definitions and jargon, as well as at least recognize basic power quality disturbance waveforms. 

Their objectives will be somewhat different than those of manufacturers, A&E firms and utilities. End users must be concerned with power quality on more of a facility systems level. This means they must treat and think of their plant electrical system as a “power quality system”, recognizing the importance of identifying when unusual equipment behavior and operating conditions that can determine the severity of a facility's power quality problem. Customers must know when to question their power quality. End users may recognize basic disturbances and determine if they might have impacted their electrical or electronic equipment. Keeping a log of historical utility events, equipment behavior, electrical system modifications and unusual electrical measurements to name a few always end up filling holes critical in solving lingering power quality problems. Monitors determine when (date/time) disturbances occurred and provide the numerical and disturbance waveform data. Electrotek experts determine why they occurred (i.e., what in their plant allowed the disturbances to occur), why their electrical and electronic equipment reacted the way it did (e.g., malfunction or failure), as well as how to prevent the disturbances from occurring again, and how to “harden” their equipment to avoid the problem in the future. Electrotek's PQView data management and analysis software is an extremely useful diagnostic tool that can pull the puzzle pieces together to help end users determine if the right electrical conditions developed to cause a power quality problem to surface. 

End users know their facilities, electrical systems, and equipment better than anyone else. At Electrotek, we teach end users to be the “eyes and ears” of their own electrical systems, loads and power quality, as they operate and maintain their facilities and plants. End users don’t have to become experts at all-things-power-quality to learn and become proficient in managing their internal power quality. They only have to know enough to recognize when a piece of equipment may be reacting negatively to poor power quality and recognize when it’s necessary to take proactive steps to avoid increasing the risks for developing what typically turn out to be serious and costly power quality problems. End users can rely on Electrotek to be their expert-go-to source for helping them understand what’s going on in their facilities, how to identify underlying power quality problems before they take their part of the bottom line, as well as how to avoid them in the future.