Product Overview

The HET 30kVA/20kV exciter transformer features a unique 4-winding design with individual bushings for each 10kV winding. Engineered for 30-300Hz variable frequency operation, it delivers ultra-low partial discharge (<2pC) and complies with IEC 60076-11 for high-voltage testing applications.

Electrical Specifications

Advanced Design Features

Multi-Winding Configuration

• Four independent 10kV windings with separate bushings

• Parallel/series connection options for 10kV or 20kV operation

• Individual isovolumetric capacitance cores per winding

Thermal Performance

• Continuous operation: 30 minutes at full load

• Winding temperature rise: ≤65K

• Oil temperature rise: ≤55K (top layer)

• Cooling method: ONAN with 25# transformer oil

Protection Systems

1. Overvoltage Protection

• Piezoresistors on all 4 HV outputs

• Zinc oxide arresters (20kA rating, IEC 60099-4)

• Dual-point ground connection system

2. Insulation Control

• Electrostatic shields between all HV/LV windings

• 20kV corona-free fiberglass bushings

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

Mechanical Construction

Enclosure Features

• 12-gauge steel tank with ANSI 61 gray finish

• Quad-wheel base with locking casters (250mm diameter)

• Shell-type oil tank with 50L conservator

Terminal Configuration

• 4× HV bushings with dual corona rings each

• LV terminals: Porcelain bushings (350V input)

• All connections voltage-graded per IEC 60137

Winding Technology

• Cylinder-type windings with balanced capacitance distribution

• Electrostatic compensation for uniform voltage gradient

• Compound insulation tubes for partial discharge control

• Precision top-bottom area matching (±3%)

Installation & Maintenance

Commissioning Requirements

• Minimum 1.2m clearance between phases

• Initial oil BDV ≥50kV (2.5mm gap)

• Pre-energization IR ≥10,000MΩ

Service Schedule

• Monthly: Bushing contamination checks

• Quarterly: Oil dielectric testing

• Annual: Winding resistance measurements

Typical Applications

• Multi-terminal cable testing systems

• GIS (Gas Insulated Switchgear) commissioning

• Rotating machine insulation diagnostics

• Partial discharge research setups