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Continuous monitoring of bushing and transformer insulation

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Omicron’s new Montrano online monitoring system is focused on assessing the dielectric health of power transformers under load. The system records changes in capacitance (C), dissipation/power factor (DF/PF), partial discharge (PD) and transient over-voltages. These are primary indicators of insulation breakdown, which can lead to dielectric failure in bushings and transformers.

Early detection prevents failures

Dielectric flashover of insulation in bushings and inside transformers is one of the most frequent causes of failure in power transformers. Aging insulation progressively degrades to the point that it can no longer withstand electrical stress. This can cause bushings to explode, transformer destruction and long outages for repair. The continuous monitoring of the dielectric state of bushing and transformer insulation is therefore essential for managing transformer health. Such continuous online assessments ensure safe, reliable operation during the intended service life of transformers.

Advanced warning of pending failures

Montrano provides detailed trend charts that show the dielectric state of insulation over time. Early warnings and alarms indicate the severity of negative trends. This enables users to assess the risk of failure and plan corrective action early to extent transformer service life.

Reliable online results

Montrano minimises the misleading impact that changes in grid unbalance (phase shifts) can have on C and DF/PF measurements. It achieves this by using the individual phases of a nearby voltage transformer as an absolute measurement reference. The resulting accuracy enables reliable comparison with recommended bushing supplier reference values to determine bushing insulation condition. A second transformer can be used for measurement comparison if a voltage transformer is not available. 

Additionally, Montrano employs advanced noise suppression using UHF signals and a unique gating technique for reliable PD source recognition. This enables the system to effectively separate external noise, like corona, from harmful PD. Montrano also detects transients directly at the bushings to more effectively assess their impact on bushing and transformer insulation.

Customised monitoring solution

The complete Montrano monitoring system includes a set of bushing tap adapters, UHF sensor, data acquisition units, a central computer and monitoring software. The system’s modular design allows it to be easily customised and expanded to match specific monitoring requirements.

Web-based data access

With the system’s convenient web interface, users can view data at any time to determine the actual dielectric condition of insulation in bushings and inside the transformer. The interface also enables users to schedule monitoring, set alarm and warning thresholds and check system status.

Expert monitoring support
High-voltage expertise is not required to benefit from Montrano’s powerful monitoring capabilities. Omicron’s dedicated team of HV engineers provides expert service and support. This includes onsite consultations to evaluate monitoring requirements; system installation, setup and training; as well as assistance with data evaluation and assessment reports.

Montrano continuous monitoring 
system for bushings and transformers

Montrano provides trend data
to assess transformer dielectric health

Company profile

Omicron is an international company serving the electrical power industry with innovative testing and diagnostic solutions. The application of Omicron products allows users to assess the condition of the primary and secondary equipment on their systems with complete confidence. Services offered in the area of consulting, commissioning, testing, diagnosis and training make the product range complete.

Customers in more than 140 countries rely on the company’s ability to supply leading edge technology of excellent quality. Service centres on all continents provide a broad base of knowledge and extraordinary customer support. All of this together with our strong network of sales partners is what has made our company a market leader in the electrical power industry.

Omicron electronics

Tel: + 44 (0) 1785 251000

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