Pioneering the future of power testing and monitoring
PD
Transformer PD Monitoring
Partial discharges in power transformers are localized electrical discharges that occur within insulation materials, which can weaken the insulation and lead to serious transformer failures. Monitoring and detecting partial discharges is crucial for the health and longevity of power transformers, as they are often early indicators of insulation degradation. These discharges produce pulses of energy and generate electrical noise, which can be identified using specialized sensors and monitoring equipment.
Early detection and continuous monitoring of partial discharges help utilities and operators take preventive actions, such as maintenance or replacement of the affected components, to avoid costly and unplanned transformer failures and ensuring the reliability and efficiency of power transformers in the electrical grid.
Ultra High Frequency (UHF) PD measurement utilizes the 300 Mhz-3 GHz range. In this range partial discharges produce fast electromagnetic impulses that are measured by antenna and a transducer. The UHF method is a non-destructive method for the transformer insulation system condition assessment. This frequency range is the most sensitive to small discharges, also it provides the most data for PD localization. This frequency range has high bandwidth and also is almost fully immune to outside interference.
Transformer UHF PD Monitoring
Partial discharge (PD) monitoring in power transformers is a critical aspect of their maintenance and reliability. UHF (Ultra-High Frequency) PD monitoring and traditional electrical PD monitoring are two common techniques used to detect and assess PD activity in power transformers.
•UHF PD Monitoring: UHF PD monitoring relies on detecting the electromagnetic emissions generated by PD events in the ultra-high frequency range (typically several hundreds of MHz to several GHz). Antennas or sensors are placed on the transformer to capture these signals.
• Electrical PD Monitoring: Electrical PD monitoring involves measuring the electrical impulses produced by PD events. This method typically uses capacitive or resistive couplers to capture the signals.
Transformer HFCT PD Monitoring
POWER VIEW Transformer HFCT sensors are designed to detect high-frequency electromagnetic emissions associated with PD activity in power transformers. These sensors comprise a high-frequency coil wound around the transformer’s grounding strap or core, allowing them to pick up electromagnetic signals induced by PD events. The high sensitivity of HFCT sensors enables the detection of subtle PD activity, even in the presence of significant background noise.
Partial discharge monitoring with HFCT sensors represents a valuable tool for enhancing power transformer reliability and mitigating the risks associated with insulation degradation. By leveraging the sensitivity and non-intrusive nature of HFCT sensors, utilities and operators can detect PD activity in real-time, enabling proactive maintenance interventions and optimizing transformer performance. Despite challenges, the adoption of HFCT-based PD monitoring is essential for ensuring the resilience and longevity of power transformer assets in modern electrical power systems.
By installing HFCT sensors at the grounding conductor od transformer main tank, utilities can continuously monitor PD activity and assess insulation condition in real-time.