Protection equipment for 6-35kV power grid voltage transformers

Abstract

The invention provides a piece of protection equipment for 6-35kV power grid voltage transformers, comprising voltage transformers. A measurement and control protection device is arranged beside the voltage transformers. Each voltage transformer is internally equipped with a temperature sensor. Current transformers are arranged between the voltage transformers and a power grid bus. High-voltage load switches are arranged between the current transformers and the power grid bus. By adopting the protection equipment for voltage transformers, the real-time working condition of the voltage transformers can be judged comprehensively. By tripping the load switches of the voltage transformers, abnormal bus voltage can be cut off, and damage to the voltage transformers is prevented.

Description

technical field [0001] The invention relates to a protective device in a power system, more specifically to a protective device for a voltage transformer of a 6-35kV power grid. Background technique [0002] Fully enclosed silicone rubber voltage transformers are widely used in ungrounded power grid systems of 6-35kV power grids. Compared with oil-immersed voltage transformers, they have many advantages, such as small size, high insulation level, and convenient operation and maintenance. However, due to the voltage The core shell of the transformer is fully enclosed by silicon rubber, and its heat dissipation level is poor. In the abnormal operation mode when the single phase is grounded in the 6~35kV ungrounded grid system, the ungrounded phase voltage rises to 1.732 times the normal voltage, and the electric energy load capacity of the voltage transformer is nearly 4 times the normal capacity, for example: 10kV commonly used The voltage transformer has three secondary coi...

AI Technical Summary

Problems solved by technology

[0002] Fully enclosed silicone rubber voltage transformers are widely used in ungrounded power grid systems of 6-35kV power grids. Compared with oil-immersed voltage transformers, they have many advantages, such as small size, high insulation level, and convenient operation and maintenance. However, due to the voltage The core shell of the transformer is fully enclosed by silicon rubber, and its heat dissipation level is poor

In the abnormal operation mode when the single phase is grounded in the 6~35kV ungrounded grid system, the ungrounded phase voltage rises to 1.732 times the normal voltage, and the electric energy load capacity of the voltage transformer is nearly 4 times the normal capacity, for example: 10kV commonly used The voltage transformer has three secondary coils with a capacity of 30 / 30 / 40VA. The capacity regulation requires that the power grid can run for 2-3 hours. The heat generated exceeds the normal heat dissipation level of the voltage transformer itself, causing the voltage transformer to burst and burn.

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