Power Quality Monitoring Data Analysis


With the increase in the use of non-linear electrical and electronic loads in customer facilities, the increase in grid load, the increase in weather activity and the increase in the age of the grid, today's power quality problems are more complex. To add another layer of complexity, utilities and their customers are increasing their use of distributed generation (DG) equipment. Solving a power quality problem on the grid today requires conducting a more detailed power quality data analysis than traditional analyses required. One of Electrotek’s core competencies is conducting advanced and detailed analyses of power quality monitoring data. 

Electrotek uses custom designed software tools to analyze monitoring data and a proven methodical approach to determine key information regarding the power quality upstream of the monitor towards the energy source and downstream of the monitor towards the load. Electrotek has an in-depth understanding of power quality on transmission and distribution systems and the types of power quality phenomena that cause disturbances to start developing and mature into disturbances that cause serious power quality problems. Electrotek also has an in-depth understanding of how disturbances impact customer electrical systems, impact electrical and electronic loads and how loads play a role in causing disturbances to occur.

Architecture & Engineering Firms

Customers experiencing power quality problems may return to their A&E firm to determine why a problem is occurring and how to resolve it. Most A&E firms are not prepared to deal with power quality problems and do not own power quality monitors. In fact, when called most firms look to expert power quality engineers for assistance with monitoring and data analysis. Some firms will work to have a monitor installed to collect power quality data but lack the expertise to conduct a proper analysis. 

Power quality data analysis by Electrotek expert engineers provides valuable information key to understanding, identifying, solving and preventing (UISP) power quality-related electrical and electronic equipment problems. Electrotek’s PQView expert power quality data management and analysis software includes advanced functions which can detect potential wiring- and grounding-related errors in monitoring data whether captured on a new or upgraded customer electrical systems. These functions can be incorporated into our engineering service designed to determine the location of disturbances and their cause. It is vitally important to detect wiring and grounding errors before customer equipment is energized, before disturbances generated by the utility arrive at the facility's utility service entrance and and before the customer’s own equipment begins to suffer more serious problems.

Equipment Manufacturers

While some manufacturers are learning to conduct power quality monitoring, learning how to properly analyze power quality data takes years of experience to grasp. Although reading power quality monitoring data is based on scientific and engineering principles, combining the results of a data analysis performed by Electrotek's expert engineers with our long history of experience and other key data from the problem site is truly an art. The art of recognizing disturbance data and properly utilizing the voltage and current waveforms to understand where the disturbance came from doesn’t come easy to the untrained human eye. There’s much more involved that just being able to identify a disturbance or two. Disturbances don’t occur in clean “text book” form. They occur in the real world as complex disturbances where many disturbances overlap.

Real-world disturbances typically contain a half-dozen or so power quality phenomena which work together to jeopardize the performance of electrical and electronic equipment. The first part of a disturbance may instantly place equipment in an undesirable state lowering its immunity to the next part of a disturbance. Manufacturers make the typical mistake of reviewing monitoring data and not know how to determine good power quality from bad power quality. To identify the real cause(s) of a power quality problem and provide customers with useful analyses, Electrotek developed their own advanced software to analyze power quality data. Electrotek has expert power quality data analysis engineers who have years of experience in determining the causes of power quality problems and how to solve and prevent them. Extensive training and experience is required to read disturbance waveforms and relate data to the causes and locations of disturbance-causing sources and loads as well as pin-pointing wiring and grounding problems.

End Users

While end-use customers have electricians and electrical engineers on staff, they lack experience in analyzing power quality monitoring data. Proper analysis of power quality monitoring data requires years of experience from expert power quality engineers at Electrotek. Our engineers are thoroughly educated and trained in power systems and power quality engineering. Our engineers use Electrotek’s advanced power quality data management and analysis software—PQView. PQView is designed to conduct detailed advanced analysis on power quality data and disturbance waveforms.

Analysis results identify the location of the disturbance source(s), the types of disturbances embedded in complex waveforms, the statistical nature of the disturbances—whether or not they are likely to occur again and the energy content of the disturbances including magnitude and frequency. Part of Electrotek’s expertise is to match the results of a power quality data analysis with the state and condition of their wiring and grounding system, the impact on the customer’s equipment and the appropriate power quality mitigation devices and steps to solve the problem.

End users are so accustomed to applying 60-hertz AC circuit theory to understand the operation of their electrical systems and loads. Because of the nature of non-linear loads that use electronic switching to convert AC energy to DC energy, any perturbation in the voltage applied to or current drawn by a non-linear load will cause a responding perturbation to occur. Connecting a non-linear electronic load to a linear facility electrical system is like trying to mix oil and water. Electronic loads draw non-linear current; that is, current at frequencies other than 60-hertz. Facility electrical systems were designed based on the expected use of 60-hertz current. The current required by a non-linear load will draw 60-hertz current, but it will also draw currents at other frequencies from above 60 hertz to as high as 30 MHz. 

Facility electrical systems also switch voltages and currents to control the flow of power through the system. This switching, carried out by electromechanical equipment such a circuit breaker or contactor, for example, introduces high-frequency energy into the system. This high-frequency energy tries to flow into a non-linear load along with 60-hertz current and can cause the load to malfunction or fail if the load is not designed to absorb or "reject" the energy. All AC line voltages contain energy at frequencies other than 60 hertz. In other words, all AC line voltages contain electrical disturbances as part of their every day voltage profiles. Because every power quality problem is unique just as every facility electrical system is unique, it becomes very difficult for the common electrical engineer and electrician to determine which disturbances are causing problems in a customer facility and which are not. Pulling all of this information together and conducting the appropriate power quality analysis to understand, identify, solve and prevent (UISP) power quality problems is Electrotek's expertise.