Impulse Current Generator
2ms Energy Screening Test System for MOV Arresters (150A-2200A)
This automated test system identifies defective ZnO varistor elements during production using 2ms rectangular impulses (150A-2200A) per IEC 60099-4 standards, featuring sequential testing across three terminals with integrated cooling.
Key Specifications
| Parameter | Circuit 1 | Circuit 2 | Circuit 3 |
|---|---|---|---|
| Capacitance | 8μF | 16μF | 2μF |
| Charging Voltage | 30kV | 30kV | 35kV |
| Current Peak | 850A | 1700A | 150A |
| Waveform | 2-2.4ms (±20%) | 2ms | |
System Configuration
Core Components
Charging System: 50kV/40kVA transformer (1A max current)
Energy Storage: Multi-bank capacitors (2-16μF)
Waveform Control:
Adjustable inductors (0.5mH-8mH multi-tap)
Impedance matching resistors (1-100Ω)
Test Terminals: 3-position turntable (10s charge time)
IEC 60099-4 Compliance
Peak duration: 100-120% of specified value
Total duration ≤150% of peak duration
Overshoot ≤10% of peak current
Precise disconnection timing (1-2× total duration after zero-cross)
Measurement & Control
| Component | Specification |
|---|---|
| Current Transformer | 5000A through-type (100-5000A primary, 5A secondary) |
| Voltage Divider | 25kV/250V resistive |
| Test Interval | Adjustable 10-99s (software controlled) |
| Pulse Rate | 6 pulses/minute (max) |
Automated Safety Features
Cooling System:
Forced-air cooling with directional fans
Non-contact temperature monitoring (<50°C threshold)
High-temperature alerts
Sequential Discharge: Turntable automates element handling
Isolated Design: Protected test compartments
Testing Workflow
Load MOV elements onto turntable
System automatically:
Positions element at test terminal
Charges capacitors (
<10s)<>
Applies 2ms impulse
Measures:
Peak current (150-2200A range)
Waveform parameters (Tf/Tt)
Energy absorption
Cools elements before discharge (auto-triggered if >50°C)
Rotates turntable to next test position (1-5min intervals)
Why This System?
High-Throughput: Tests 3 elements simultaneously (1 test/minute)
Precision Waveform: Meets strict IEC 60099-4 duration/overshoot requirements
Operator Safety: Automated handling of hot elements
Flexible Configuration: Adjustable L/C components for different MOV grades
Conclusion
This 2ms energy screening system provides complete production-line testing of MOV arresters per IEC 60099-4, combining high-current impulses (up to 2200A) with automated element handling and temperature-controlled safety. The triple-test-terminal design ensures efficient quality control for ZnO varistor manufacturing.
