Noah

1. Incident BackgroundOn April 25, 2026, the customer reported that after a local grid power outage and restoration, a QM unit in an SM66 cabinet failed to activate, and two internal fuse tubes were blown. Subsequent inspection revealed red oil level alarms on both Transformer 1 and Transformer 2, along with relay abnormalities. After venting, testing, and disassembly, it was confirmed that Transformer 1 was damaged due to oil loss causing switch burn-out, while Transformer 2 remained operationa

The Most Widely Used Power Transformers: Oil-Immersed and Dry-Type Resin TransformersThe two most widely used power transformers today are oil-immersed transformers and dry-type resin transformers. The insulation system of a power transformer, composed of various insulating materials, is fundamental to its proper operation. A transformer's service life is primarily determined by the lifespan of its insulating materials (oil-paper or resin).In practice, most transformer failures result from damag

Transformer grounding protection measures are divided into two types: The first is transformer neutral point grounding. This protection measure prevents neutral point voltage drift caused by three-phase load imbalance during transformer operation, enabling protection devices to trip quickly and reducing short-circuit currents. This is considered functional grounding for the transformer. The second measure is grounding of the transformer core and clamps.This protection prevents induced voltages f

The rural power grid transformation plays an important role in reducing rural electricity tariffs and accelerating rural economic development. Recently, the author participated in the design of several small-scale rural power grid transformation projects or conventional substations. In rural power grid substations, conventional 10kV systems mostly adopt 10kV outdoor auto circuit vacuum reclosers.To save investment, we adopted a scheme in the transformation that removes the control unit of the 10

In recent years, the accident rate of H59 distribution transformers has shown an upward trend. This article analyzes the causes of failures in H59 distribution transformers and proposes a series of preventive measures to ensure their normal operation and provide effective assurance for power supply.H59 distribution transformers play a vital role in power systems. With the continuous expansion of power system scale and the increasing single-unit capacity of transformers, any transformer failure n

Measures to Prevent H59 Oil Immersed Power Distribution Transformer from Burning OutIn power systems, H59 Oil Immersed Power Distribution Transformer play an extremely critical role. Once burned out, they can cause widespread power outages, directly or indirectly affecting the production and daily lives of a large number of electricity users. Based on the analysis of multiple transformer burnout incidents, the author believes that a considerable number of such failures could have been avoided or