Products
SIGMA – LTC Assist On-line Monitoring Sub-system Maintenance Assistant for On-load Tap Changer
The Load Tap Changer (LTC) is one of the principal sources of failures in power transformers, due to the presence of moving parts that conduct and interrupt high currents while exposed to high electrical potentials. For this reason, as well as failures of a thermal and mechanical nature (see SIGMA LTC Diff and SIGMA LTC…
SIGMA – LTC Diff On-line Monitoring Sub-system Load Tap Changer Temperature Differential
The Load Tap Changer (LTC) is one of the principal sources of failure in power transformers, arising from the moving parts that conduct and interrupt high currents while exposed to high electrical potentials. The most common of these tap changer modes of failure are related to the contact deterioration or mechanical wear and tear that…
SIGMA – LTC Torque On-line Monitoring Sub-system Load Tap Changer Motor Torque
The Load Tap Changer (LTC) is one of the principal sources of failures in power transformers, arising from the existence of moving parts that conduct and interrupt high currents while exposed to high electrical potentials. As well as thermal failures (see SIGMA LTC Diff Sub-system), some of the common failure modes in LTCs are of…
SIGMA – Chroma On-line Monitoring Sub-system Dissolved Hydrogen, Chromatographic and Physical-chemical Tests
Gases dissolved in oil is recognized as one of the best indicators of the internal condition of transformers and reactors, and the analysis of the gas content of oil was largely propagated as a diagnostic tool for this equipment. This resulted in the development of a broad knowledge base and diverse techniques, to analyse the…
SIGMA – Efficiency On-line Monitoring Sub-system Cooling System Efficiency
Appropriate cooling of a transformer is fundamental for its safe operation to prevent the acceleration in the loss of useful insulation life, in the presence of high loading. Therefore, it is essential that the natural and forced cooling equipment, such as radiators, fans and oil pumps, should be in perfect working order, efficiently dissipating heat…
SIGMA – Fan On-line Monitoring Sub-system Assistant for Maintenance of the Cooling System
Adequate cooling of a transformer is fundamental for its safe operation and the prevention of accelerated aging and reduction in the useful insulation life under high loading. Thus, it is essential that the forced cooling equipment, such as fans and oil pumps, function perfectly. The total or partial failure of the cooling equipment can activate…
SS – Surge Suppression Module
The Surge Suppression Module or SS has the function to protect the service life of electronic equipment against transient voltage surges from external sources in an electric power substation. The external and internal transient voltage surges directly affect the performance and the service life expectancy of electronic equipment. Available to protect power supplies from 0…
SIGMA – Ageing On-line Monitoring Sub-system Insulation Ageing
Under normal operation conditions, a useful life of a transformer is principally determined by the life of its insulation. Whilst an aged insulation would not be directly responsible for ending a transformer’s working life, in the majority of cases, the deterioration of its mechanical properties increases the risk of failure in the presence of forces…
TS – Temperature Supervisor for Oil-immersed Transformers
Thermal monitoring of oil-immersed transformers is essential for their safe operation. This is the case not only for large-scale equipment, but also for medium-sized transformers and distribution transformers, thus achieving maximum return from the investment in these assets without jeopardizing their life cycle. The Temperature Supervisor’s competitive cost allows the inclusion of thermal monitoring for…