Product Overview

The HET 40kVA exciter transformer delivers precision testing with dual-voltage outputs (10kV/5kV) and ultra-low partial discharge (<5pC). Designed with ONAN cooling and advanced electrostatic shielding, it complies with IEC 60076-11 for demanding high-voltage applications.

Electrical Specifications

Key Features

Dual-Voltage Operation

• Tap-selected outputs without manual reconfiguration

• Common LV winding with multi-tap HV design

• Automatic voltage stabilization during switching

Thermal Performance

• ONAN cooling with 25# transformer oil

• Continuous operation at full rated capacity

• Winding temperature rise ≤65K

Protection Systems

1. Overvoltage Protection

• Piezoresistors on all HV outputs

• Zinc oxide arresters (15kA rating, IEC 60099-4)

• Dual ground reference points for operator safety

2. Insulation Control

• 10kV corona-free fiberglass bushings

• Electrostatic shielding between all windings

• Isovolumetric capacitance cores in HV bushings

Mechanical Design

Enclosure Features

• 12-gauge steel housing with corrosion-resistant coating

• Wheel-mounted (4× industrial casters with brakes)

• Shell-type oil tank with 50L conservator

Terminal Configuration

• LV terminals: High-creepage porcelain bushings

• HV terminals: Fiberglass-reinforced epoxy bushings

• All bushings feature dual corona rings

Winding Technology

• Cylinder-type windings with balanced capacitance

• Electrostatic compensation for uniform voltage gradient

• Inter-turn insulation (1.5mm Nomex® layers)

• Compound insulation tubes for partial discharge control

Installation & Maintenance

Commissioning Requirements

• Minimum 1.2m clearance from grounded objects

• Initial oil BDV ≥45kV (2.5mm gap)

• Pre-operation IR ≥8,000MΩ

Service Schedule

• Monthly: Bushing contamination inspection

• Quarterly: Oil dielectric strength testing

• Annual: Complete winding resistance test

Typical Applications

• Power cable withstand testing

• GIS (Gas Insulated Switchgear) commissioning

• Transformer impulse testing systems

• High-voltage component research & development