Commissioning and maintenance procedures for low-voltage circuit breakers may include testing to determine whether the circuit breaker is able to respond correctly to faults or overload conditions as specified in the coordination study. This requirement may include ground fault (GF) as part of the protection scheme. Testing may be performed through primary or secondary injection; primary injection is the best …
Communication plays a critical role in the operation of modern substations. As the industry was evolving into the digital age, there was a need for a unified communication architecture, and the International Electrotechnical Commission (IEC) began to develop international standards for communication. In this quiz, we will explore the international communication standard IEC 61850. 1. What is the international standard …
It is said that spring is a time of new growth for Mother Nature, but it is also true for many man-made industries. It can be a time of heavy workload, especially for construction and related industries. Each season presents very real hazards that everyone must be made aware of. It is a good idea to train employees about these …
A numerical feeder protection relay would trip when a collector feeder breaker is closed due to inrush at a solar photovoltaic site. The inrush current is due to energizing power transformers. This article demonstrates how to use harmonic blocking to prevent this unwanted tripping. Magnetizing inrush currents may cause overcurrent elements to operate when the line is energized. The fundamental …
A major event occurred at a large power plant in the southwest region. A new generator circuit breaker (GCB) had been installed for a combined cycle power block (CCPB) consisting of a gas turbine generator (CTG) and a steam turbine generator (STG). The new GCB is located on the low side of the generator step-up transformer (GSU) serving the CTG. …
As advancements in technology have driven the world over the past 20 years, the ability to protect and control our electrical infrastructure has advanced as well. By implementing advanced technologies and innovative solutions, the grid has undergone a significant transformation, accommodating the growing demands of an increasingly digital and interconnected world. The enhanced visibility and automation have improved grid resilience, …