Mining Dry-Type Transformer

I. Working Principle
The mining dry-type transformer operates on the fundamental law of electromagnetic induction. Alternating current supplied to the primary winding generates an alternating magnetic field, which is coupled through the core to induce required voltages in the secondary winding, thereby achieving efficient voltage transformation. Unlike standard industrial dry-type transformers, it adopts an epoxy resin vacuum-cast, fully sealed structure. The high and low-voltage windings are hermetically encapsulated in high-performance resin, eliminating flammable insulating oil entirely. The unit relies on natural air convection (AN) or forced-air cooling (AF) for thermal dissipation, making it ideally suited for the hazardous, explosion-proof, and moisture-prone environments of underground mining.

II. Key Performance Characteristics

Major Advantages:

Inherent Safety & Flame Retardancy: Completely free of transformer oil, eliminating all risks of oil leaks, fires, or explosions. The resin-cast windings feature outstanding arc resistance and self-extinguishing properties, preventing the ignition of underground methane (firedamp) and coal dust, and fully complying with stringent underground explosion-proof safety standards.

Superior Environmental Resilience: The fully sealed encapsulation offers exceptional resistance against dust, moisture, condensation, and dripping water, reliably withstanding harsh underground conditions characterized by high humidity, airborne particulates, and corrosive gases.

Simplified Maintenance: Eliminates tedious routine procedures such as insulating oil sampling, laboratory testing, oil purification, and replacement, significantly reducing operational expenditure. It is typically equipped with an intelligent temperature control system (PTC/Pt100) for real-time winding thermal monitoring, over-temperature alarming, and trip protection.

High Flexibility & Compactness: Features rugged, vibration-resistant construction that allows compact spatial integration, making it the perfect match for underground mobile substation skids.

Inherent Limitations:

Higher Cost & Thermal Constraints: Initial procurement costs are higher than equivalent oil-immersed transformers. Due to thermal conduction limits imposed by the solid resin encapsulation, short-term overload capacity is slightly lower than that of oil-filled counterparts.

Difficult Field Repair: The resin encapsulation is a monolithic solid structure, rendering field insulation repairs virtually impossible. In the event of severe winding internal faults, complete replacement or factory overhaul is usually required.

Weight & Logistical Challenges: Due to robust enclosures and dense casting construction, high-capacity models are relatively heavy, posing logistical challenges during underground transport and maneuvering in restricted spaces.

III. Application Scenarios
Primarily deployed in underground coal mines, metal, and non-metal subterranean mining power distribution networks, frequently serving as the core transformer unit for explosion-proof mobile substations:

Mining Machinery Power Supply: Delivering low-voltage power to underground continuous miners, roadheaders, heavy-duty armored face conveyors (AFCs), belt conveyors, and hydraulic pump stations.

Auxiliary & Safety Infrastructure: Supplying power to underground working faces, tunnel lighting, environmental monitoring systems, and underground communication networks.

Critical Infrastructure Feeding: Powering essential underground installations such as main drainage pump rooms and auxiliary ventilation fans.

Surface Industrial Facilities: Widely utilized in open-pit mining operations, coal preparation plants, and mineral processing facilities characterized by heavy dust accumulation or stringent fire safety requirements.

Summary
With intrinsic safety, fire resistance, and explosion-proof capability as its core strengths, the mining dry-type transformer stands as vital backbone equipment ensuring safe and continuous power supply in underground mines. By leveraging a fully sealed resin-cast dry structure to eradicate oil-related fire and explosion hazards, it guarantees secure power delivery for gassy underground mobile substations and heavy extraction machinery.

Specification for 10000V Mining Dry-type Transformer

Specification for 6000V Mining Dry-type Transformer