Power quality analysis: Detecting phenomena that run through electrical networks
November 7, 2022
In electrical installations, various disturbances can affect the operation and lifespan of critical equipment. For this reason, an increasing number of companies are incorporating power quality studies into their electrical maintenance programs. In this article, academics and specialists share their perspectives on the matter.
As industries adopt more digital technologies in their processes, their equipment becomes increasingly vulnerable to electrical network disturbances. Issues such as swells, sags, harmonics, and flicker can significantly impact sensitive equipment, such as computers and PLCs, leading to malfunctions, total failures, or even accidents. Consequently, more companies are turning to power quality analysis to eliminate the “impurities” present in their electrical networks.
Christian Rojas Monrroy, a professor in the Department of Electronics at Universidad Técnica Federico Santa María and a member of AIE, defines power quality analysis as “a procedure used to assess the adequacy of an electrical installation to ensure and support the operation of its loads. This process evaluates electrical variables as well as the reliability of the electrical power service.”
José Mancilla, a professor at the DuocUC Puente Alto School of Engineering, elaborates: “Power quality analysis is an electrical input diagnosis that identifies anomalies that could compromise safety, cause equipment failures, disrupt operational continuity, or hinder energy savings.”
Jorge Huerta Plaza, a professor at the Industrial Processes School of Instituto Profesional IACC and an AIE member, adds: “All systems experience disturbances that alter signals. A power quality analysis detects voltage, current, or frequency deviations that lead to deterioration or malfunction of various loads. Common problems identified include device and equipment damage, increased energy losses, and higher costs or decreased system reliability.”
Héctor Palma, General Manager of PQMetering, agrees: “The industrial sector undeniably relies on the electrical system for effective and efficient operation. Disturbances not only reduce efficiency but also pose risks of additional problems. Power quality studies are essential to prevent these issues and enable businesses to perform optimally. Such studies aim to determine how closely an industrial power supply system resembles an ideal system.”
Secondary Effects
Leonardo Burgos Concha, an electrical instrumentation specialist at AVANTEC, explains that “in every industrial process, machinery and various types of lighting installed on the same electrical network generate energy consumption while also introducing ‘secondary effects’ that pollute the network and cause problems. These studies aim to identify and address phenomena that disrupt electrical networks within a facility.”
Cristian Vargas Ravelo, a professor in Electricity, Electronics, and Telecommunications at INACAP Concepción-Talcahuano and an AIE member, emphasizes that “power quality relates to the reliability of an electrical system. Ensuring the safety of both installations and personnel depends on monitoring and guaranteeing the proper functioning of all components through studies like these.”
Leonardo Araya, a professor at INACAP La Granja, explains that such studies can detect parameter deviations, such as voltage and frequency variations and supply interruptions. “Internally, an analysis might uncover excessive harmonics, poor power factor, or inadequately sized conductors, leading to losses from overheating,” he adds.
Luis Emilio Zapata, a professor in the Industrial Area of Iplacex School of Technology and an AIE member, highlights two monitoring systems: temporary systems for detecting specific issues over short periods and permanent systems for continuous quality monitoring, which provide real-time data and long-term benefits.
Carlos Silva M., Ph.D., an academic and researcher at the Energy Transition Center (CENTRA) at Universidad Adolfo Ibáñez, clarifies that the Technical Quality of Service Standard for Distribution Systems (2019) defines three components of service quality: product quality (voltage shape, magnitude, frequency, and harmonics), supply quality (frequency and duration of interruptions), and commercial quality (service and customer care). Silva notes that the emerging challenges in the sector are centered on the concept of product quality.
Tools and Standards
Luis Ojeda Diaz, a professor at INACAP Punta Arenas, mentions that the applicable national standard is DS-327, while international standards include IEEE 519, EN50160, and IEC 61000 series. “The IEEE 1159-1995 standard, ‘Recommended Practice for Monitoring Electric Power Quality,’ defines power quality issues,” Ojeda concludes.
Components of a Power Quality Analysis
According to Zapata, power quality analysis aims to evaluate electrical problems, including transients, harmonics, voltage regulation, power factor, grounding systems, and dynamic voltage fluctuations. The process includes three steps:
- Electrical Quality Analysis: Ensures compliance with national and international standards.
- Preliminary Analysis: Reviews previously identified issues.
- Visual Inspection: Examines and documents the electrical installation.
Sergio Flores Zúñiga, a professor at INACAP Punta Arenas, explains that while permanent monitoring is ideal, it is costly due to the complexity of industrial systems. Thus, monitoring is often conducted periodically to maintain control.
Distributors are required to comply with the Quality of Service Electrical Standard (NTCS), which mandates periodic random measurements of regulated clients. These measurements, typically over seven days, track parameters every 10 to 15 minutes.
Importance of Instrumentation
Effective power quality studies require specialized tools, such as single-phase and three-phase power quality analyzers. These devices are categorized by precision into Class S and Class A, the latter being the most accurate. Burgos recommends regular inspections with the proper instrumentation to prevent failures.
Palma emphasizes that “monitoring is the first and most crucial step in identifying and resolving power quality issues, enabling better energy management and real savings for businesses.”
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