Technical Specification: AC Test System with Ultra-Low Partial Discharge

Precision Power Frequency Testing for HV Components & Insulation Systems

Core Functionality

This specialized AC test system delivers 120kV power frequency voltage with minimized partial discharge (PD) levels for reliable factory testing of high-voltage components. Designed for both standard compliance checks and advanced research applications.

Key Specifications

Parameter                                          Value

Output Voltage                                  120 kV AC (50/60 Hz)

Partial Discharge Level                      < 5 pC (typical at 100 kV)

Test Modes                                         Withstand Voltage • PD Measurement • Research Tests

Voltage Regulation                             ±1% (0-120kV range)

Load Compatibility                             Capacitive • Resistive • Inductive

Test Applications

Power Frequency Withstand Tests per IEC 60270 & IEEE 4™

Partial Discharge Factory Testing for:

    • Instrument transformers (VTs/CTs)

    • Circuit breakers & disconnectors

    • Bushings & insulators

    • Gas-insulated switchgear (GIS)

Dielectric Research on insulation materials

Design Advantages

✅ One-Stage Transformer Technology

Eliminates cascaded voltage drop

Enhanced waveform purity (THD <2%)

Reduced maintenance vs. multi-stage systems

✅ Multi-Load Capability

Optimized for capacitive loads (e.g., cables, bushings)

Integrated compensation for inductive loads (reactors, transformers)

Resistive load stability (1-500 kΩ range)

✅ Ultra-Low PD Background

Shielding: Double-layer EMI enclosure

Grounding: <2Ω earth resistance requirement

Connections: Corona-free terminals

System Components

1. **120kV AC Transformer**  

- Oil-insulated • ONAN cooling  

- 150 kVA base rating (scalable)  

2. **Control Console**  

- Digital kV-meter (0.5 class)  

- PD measurement interface (IEC 60270 compliant)  

- Ramp rate control (0.1-5 kV/s)  

3. **Safety System**  

- Overcurrent trip (0.1s response)  

- Emergency off-circuit  

- Flashover protection  

Compliance & Standards

Factory acceptance tests: IEC 60060-1, IEEE Std 4™

Partial discharge: IEC 60270, EN 60270

Safety: IEC 61010-1, OSHA 29 CFR 1910

*"The single-stage design achieves PD levels 60% lower than cascaded systems – critical for detecting micro-defects in HV insulation."*

Typical Test Configurations

Insulator String Test: 120kV/60 min withstand + PD <10pC

VT Validation: Step-up to 150% rated voltage

GIS Section Test: 80kV PD measurement @ 1.1 Ur

Request Custom Configuration

Contact engineers for solutions optimized for:

Higher voltage needs (up to 300kV)

Specific PD sensitivity requirements

Automated test sequences