A detection method for open circuit fault of dyn11 type distribution transformer winding connection joint

Abstract

A Dyn11 distribution transformer winding connection joint open-circuit fault detection method comprises the following steps: after an open-circuit fault occurs to the windings of a Dyn11 distribution transformer, the voltage and phase change at a low-voltage side outlet of the distribution transformer is analyzed; the voltage amplitude and phase at the low-voltage side of the distribution transformer are measured in real time using a PMU synchronous phasor measurement unit, the collected voltage amplitude and phase are stored and compared with preset thresholds, and the collected voltage amplitude and phase need to be actively uploaded to a monitoring master station if the collected voltage amplitude and phase exceed the preset thresholds; and the master station studies and determines the type of open circuit based on the specific changes of the received voltage amplitude and phase and according to a logic judgment relationship, adopts different auxiliary decisions according to the power supply network topology and the open-circuit type, and pushes the open-circuit type to an equipment owner in order to process the alarm information in a timely manner and conduct related emergency repair work. The scheme of the invention is applied to Dyn11 distribution transformer winding connection joint open-circuit detection methods and online monitoring devices.

Description

technical field [0001] The invention relates to a detection method for an open circuit fault of a Dyn11 type distribution transformer winding connection joint, belonging to the technical field of distribution transformer maintenance. Background technique [0002] Dyn11 type distribution transformer has been widely used in power system and user side due to its good quality such as economy, high sensitivity to single-phase grounding, and adaptability to unbalanced three-phase load. At present, the fault monitoring level of the medium and low voltage distribution network is low. The dispatching can only monitor the outage of the entire distribution line or the single-phase grounding fault based on the information of the SCADA system, but the faults in some sections and some stations of the distribution line cannot be detected in time. The internal high-voltage winding of Dyn11 type distribution transformer has relatively few open-circuit faults, but once it occurs, it will inev...

AI Technical Summary

Problems solved by technology

At present, the level of fault monitoring in medium and low voltage distribution networks is relatively low. Dispatching can only monitor the outage of the entire distribution line or single-phase ground fault based on the information of the SCADA system, but it is impossible to detect faults in some sections and stations of the distribution line in time.

The internal high-voltage winding of Dyn11 type distribution transformer has relatively few open circuit faults, but once it occurs, it will inevitably cause the reverse rotation of the three-phase motor or the damage of the three-phase motor stall or the power failure of the user, which will seriously affect the product quality and even cause personal safety problems.

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