Trends in Power Quality Monitoring P

Power quality (PQ) has become an important concern for utility, facility, and consulting engineers in recent years. End-use equipment is more sensitive to disturbances that arise both on the supplying power system and within the customer facilities. Also, this equipment is more interconnected in networks and industrial processes so that the impacts of a problem with any piece of equipment are much more severe. The increased concern for PQ has resulted in significant advances in monitoring equipment that can be used to characterize disturbances and PQ variations. Analysis tools can present the PQ information as individual events (disturbance waveforms), trends, or statistical summaries. By comparing events with libraries of typical PQ variation characteristics and correlating with system events (e.g., capacitor switching), causes of the variations can be determined. In the same manner, the measured data should be correlated with impacts to help characterize the sensitivity of end use equipment to PQ variations. This will help identify equipment that requires power conditioning and provide specifications for the protection that can be developed based on the PQ variation characteristics. Understanding the performance of the power system is becoming increasingly important. PQ variations such as momentary interruptions, voltage sags, capacitor switching transients, and harmonic distortion can impact customer operations, causing equipment malfunctions and significant costs in lost production and downtime. Reliability and PQ are key requirements for the digital economy and for many process industries. Electric utilities must be able to characterize and assess the system performance at all levels of the system. This performance information must be available in a form that customers can use to evaluate the impacts on their processes and to evaluate the economics of PQ improvement alternatives. The performance information should also be shared throughout the utility so that problem areas can be identified and solutions implemented. Technologies to continuously monitor performance are available, and the Internet provides a convenient method for sharing the information with all interested parties.