The Intellix BMT 330 continuously monitors the condition of bushings in real-time and provides end users with the information they are used to receiving from off-line tests, namely changes in capacitance and power factor (tan delta), to assess the bushing dielectric efficiency and insulation integrity.

Using custom made adapters connected at the bushing tapping points, the Intellix BMT 330 measures:

• The change in bushing leakage current compared with the original values calculated from the bushing nameplate information.
• The timing differences between the 3 bushing current phases, which translate to phase angle differences relative to each other.

The Intellix BMT 330 measures both oil and ambient temperature. It correlates capacitance changes linked to thermal expansion of the bushing and compensates for the measurements being made at actual bushing operating temperature compared with nameplate values obtained off-line.

PD is a localized breakdown of a small portion of a solid or fluid electrical insulation system that is under high voltage stress, which does not completely bridge the space between two conductors. PD results in localized gradual erosion of the insulation system that eventually leads to failure of the critical insulation between transformer windings. Using the same bushing adapters, the Intellix BMT 330 offers the added advantage of measuring high frequency signals in order to monitor PD activity, giving an added level of protection for the main tank of the transformer.

The amplitude of the PD pulses, as well as the number of pulses, are recorded and used to calculate an overall measure of PD activity. Several methods are used to discriminate between internal PD and external noise (corona discharge).

The Intellix BMT 330 can easily be integrated with GE Vernova's Kelman DGA analyzer, giving the end user a unique all-in-one solution that provides a more comprehensive view of the transformer's overall condition, from bushing diagnostics and PD, to complete main tank monitoring.

Having an all-in-one integrated solution from GE Vernova will significantly increase the ability to detect potential transformer problems at an early stage. The system will provide status on:

• Deterioration of the bushing insulation
• Partial discharge activity
• Moisture content in oil
• Developing key fault gases H₂, CO, C₂H₂, C₂H₄, C₂H₆, CO₂ and CH₄

This helps to decrease the risk of unplanned downtime and improve network reliability.

GE Vernova's Perception software allows an operator to easily download and visualize the data available from a critical transformer and use it to make better, more informed decisions. The software is an upgradeable tool, allowing users to view all relevant transformer data from one centralized point .

Having a one-source provider for complete transformer monitoring activities can effectively lower installation costs, as well as reduce the administrative burden of coordinating various maintenance crews. GE Vernova has extensive experience and worldwide resources available to deliver integrated monitoring solutions and assist customers with transformer challenges, including installations, commissioning, training and on-going technical support.

Substation Automation Example

The application below showcases an integrated solution for bushing and transformer main tank monitoring utilizing the Intellix BMT 330, the Kelman DGA analyzer and the Perception software for data analysis.

Per IEEE C57.13.6, a 0.15S class CT must maintain 0.15 accuracy from 5% of rated current through rating factor. This is a significantly tighter tolerance for error as compared to a standard CT: 2X better within rating factor and 4X better at light loads.

With GE Vernova’s RevenueSense CT’s, this tight tolerance of 0.15 accuracy is maintained for an extended range of 1% of rated current through rating factor. Similar to Encompass CT’s, moving from a standard CT to a wide range CT allows for a reduction in inventory, part numbers, and billing multipliers.

However, where Encompass CT’s offer equal performance over an extended range, RevenueSense CT’s offer improved high accuracy performance, allowing for increased billing accuracy and increased revenue.

The RevenueSense CT with rated range from 1% up through a rating factor of 3 covers the operating range of up to 8 other standard ratios, allowing for up to 90% reduction in inventory requirements. Additionally, the tolerance for CT error is tighter over the entire range, allowing for improved metering accuracy, particularly at light loads.

In this business case example, a commercial customer requires premium accuracy to maximize billing revenue. The assumed hours of operation for this business are Monday to Friday, 9am to 5pm. The business is closed weeknights and weekends.

The RevenueSense CT, with its premium accuracy increases billing revenue by $40.93 annually versus the standard CT. The additional cost of three high accuracy CT’s is roughly $60 in this example, yielding a payback in less than 18 months.

* JAK-0S also available with RF=2 with high burden

Indoor Voltage Transformers

Outdoor Current Transformers 

Outdoor Voltage Transformers