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• Dielectric Fault Analyzer DFA100
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• Intelligent Diagnostic Devices
• Leakage Current Monitor
• M2H - MCM
• M4000 Series
• M5000 Series
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• ProTesT software
• TDR Series

Intelligent Diagnostic Devices (IDDs)

A family of continuous online diagnostic devices for power system apparatus

Doble's Intelligent Diagnostic Devices (IDDs) are a cost-effective online diagnostic system used to monitor electrical apparatus in the field. Each IDD is intended to be apparatus-specific and can be mounted in existing enclosures or in optional enclosures available from Doble. The IDD is easy to install and, onceconfigured, operates continuously.

IDDs are designed to operate reliably under extreme weather conditions and electrical interference found in normal substation operations. Self-diagnostics continuously track the condition of the IDD and issue alerts if an abnormality is detected in the system. Diagnostics also validate the information supplied by the gas monitor; only values determined to be valid are used in calculations made by the IDD.

IDD for Moisture in Transformers

Assessing the moisture content in insulation is a key factor to ensure transformer reliability and longevity. The moisture content in oil is continuously changing and could have adverse effects, mostly on oil quality.The Doble Expert System calculates the dielectric breakdown strength of the insulating fluid.

In addition to measuring the moisture in oil, IDD for Moisture estimates the water content of the paper, where the majority of the moisture resides. This permits tracking changes to detect when water vapor bubbles could form during overloads.It is essential to know the amount of moisture in the solid insulation, to determine the transformer's short- and long-term health.

IDD for Dissolved Gas in Oil Analysis (DGA)

The industry has come to rely on dissolved gas analysis to assess the condition of oil-filled transformers. It's so effective that some utilities employ online monitors to continuously measure the gas content in their transformers' insulation fluid. Yet online monitors provide just part of the solution needed to insure reliable operation. The data still needs to be reviewed by an expert to analyze its meaning. The IDD for dissolved gas captures information from a gas sensor (not included), performs additional calculations, evaluates the results, provides data storage and, if necessary, notifies of impending problems.

The rate of change of dissolved gas is often the most relevant indication of transformer condition. The IDD for DGA evaluates this critical factor for diagnosing the severity of abnormalities. By employing four trending cycles (short, medium, long and very long) the diagnostic analysis can identify a complete range of problems. This includes high rate of gas generation and short gestation periods to low levels of gas production over long periods of time.

IDD for Bushings and CTs

This revolutionary online diagnostic package continually monitors bushings and CTs. The IDD detects abnormalities in the insulation system and, when appropriate, issues alerts, both locally and remotely. IDD keeps asset managers informed of the status of their bushings, providing them lead time to determine appropriate corrective action when needed.

The IDD identifies the bushing that is manifesting abnormally and performs an analysis on the leakage current, providing assessment of the insulation system. The Expert System calculates the absolute and rate of change of power/dissipation factor and capacitance of the problem bushing, providing diagnostic information to determine the severity of the problem. The advance signal processing and field-proven algorithms eliminate the effect of noise and other environmental conditions that could lead to incorrect diagnosis of the bushing status and inappropriate corrective actions.

Features and Benefits

• Continuous Condition Assessment. The status of the equipment is constantly being evaluated by the field-proven Expert System, minimizing the need to perform routine testing.
• Early Identification of Problems. Refined signal processing and field-proven analysis identify abnormalities, anticipate failures, and eliminate false alerts.
• Prioritized Alerts. Based on the significance of the incipient problem, the analysis issues an alert indicating the criticality of the problem, providing a tool to manage risk.
• Specifies Corrective Action. An alert identifies the problem and prompts corrective action.
• Simple Installation. The IDDS are self-contained devices that require only connecting sensors, input power, and optional remote communication to complete installation with minimum outage time and resources.