Free Expert Guides on Power Systems, Circuit Design & Electrical Troubleshooting

1. Causes of ResonanceA 500kV GIS switching station is designed following the principle of “primary equipment intelligence and secondary equipment networking”. The PT high - voltage side has no disconnector and is directly connected to the bus GIS. Through the analysis of fault recording diagrams, when the 5021 circuit breaker opens, the fracture capacitance and PT form a series circuit. Moreover, the bus voltage, after being paralleled by the PT inductance, shows inductive c

Automatic backup switching (ABTS) devices are core components ensuring the safe, reliable, and stable operation of factory power grids. Their startup logic strictly follows the dual criteria of "loss of voltage in the working power supply + no - current detection", effectively avoiding misjudgments caused by secondary disconnection of voltage transformers (VTs) or maloperations of ABTS due to secondary circuit faults of current transformers (CTs). The activation condition requires both "no volta

Practical Experience Sharing from an Electrical Engineer in the FieldBy Oliver, 8 Years in the Electrical IndustryHi everyone, I'm Oliver, and I've been working in the electrical industry for 8 years.From early involvement in substation commissioning and equipment inspection, to now managing the maintenance and fault analysis of entire power systems, one of the most frequently encountered devices in my work has been the voltage transformer (VT / PT).Recently, a friend who's just starting out ask

By Echo, 12 Years in the Electrical IndustryHi everyone, I'm Echo, and I've been working in the electrical industry for 12 years.From early involvement in commissioning and maintenance of distribution rooms to later participation in electrical system design and equipment selection for large-scale projects, I’ve witnessed how voltage transformers have evolved — from traditional analog devices to intelligent, digital components.The other day, a new colleague from a power compan

With the rapid development of power systems, electronic voltage transformers (EVTs), as key measurement devices in power systems, their performance stability and reliability are crucial for the safe and stable operation of power systems. The electromagnetic compatibility (EMC) performance, as one of the core indicators of EVTs, is directly related to the ability of the device to work normally in complex electromagnetic environments and whether it will cause electromagnetic interference to other

1. Fault SituationIn September 2023, as a front - line fault maintenance worker, I detected abnormal voltage on the 10kV Section I bus of a substation during monitoring duty and informed the operation and maintenance team. The monitoring system showed: U0 = 0 kV, Ua = 6.06 kV, Ub = 5.93 kV, Uc = 6.05 kV, Uab = 10.05 kV, Ubc = 5.94 kVMy team and I rushed to the site. We suspected the secondary air circuit breaker of the 10kV Section I bus voltage transformer was closed and found the U - phase fus

By Felix, 15 Years in the Electrical IndustryHi everyone, I'm Felix, and I've been working in the electrical industry for 15 years.From early involvement in traditional substation commissioning and maintenance to now managing electrical system operations for multiple photovoltaic and wind power projects, one of the most frequently encountered devices I deal with is the Electromagnetic Voltage Transformer (PT).The other day, a shift operator at a new energy plant asked me: “We have an e