Is the application of 11kV surge arresters technically feasible in substation environments?

June 20, 2025

As an 11kV surge arrester supplier, I confirm these units are suitable for substations—with critical voltage-specific considerations.

1. Core Functionality

Surge arresters protect substation equipment (transformers, switchgear) from overvoltages caused by:Lightning strikes,Switching operations,Grid transients.

They divert excess current to ground, preventing insulation damage .

2. Applicability in 11kV Substation Sections

Ideal for:

11kV switchgear bays

Distribution transformers (11kV windings)

Feeder/cable terminations

Not suitable for:

Higher-voltage sections (e.g., 24kV/36kV busbars)

Generator step-up transformers

3. Advantages

Cost Efficiency: Lower cost than higher-voltage arresters (e.g., 24kV/36kV), enabling multi-point protection.

Voltage Matching: Optimized for 11kV system parameters (e.g., continuous operating voltage ≥ 9kV per IEC 60099-4).

Targeted Protection: Mitigates typical 11kV surge profiles (e.g., 8/20μs impulses up to 40kA) .

4. Limitations & Risks

Voltage Mismatch: Using 11kV arresters on >11kV equipment risks:

Thermal runaway during overvoltages

Failure to clamp surges, leading to equipment damage

Inadequate Energy Handling: Higher-voltage sections require arresters with larger energy ratings (e.g., 36kV units for 36kV buses) .

5. Selection Criteria

System Voltage: Verify equipment operating voltage (must match arrester rating).

Surge Type:

Lightning-prone sites: Prioritize high discharge capacity (>20kA).

Switching-heavy grids: Focus on fast response time (<100ns).

Location: Coastal/industrial sites demand pollution-resistant housings (e.g., silicone rubber with creepage ≥25mm/kV) .

6. Complementary Solutions

For multi-voltage substations:

24kV Sections: Use 24kV Surge Arresters(rated Uc ≥ 19kV).

36kV Sections: Deploy 36kV Surge Arresters (energy absorption >15kJ/kV).

Conclusion

11kV surge arresters effectively protect 11kV substation equipment when voltage-matched. For mixed-voltage sites, combine with higher-rated units (24kV/36kV) for comprehensive coverage. Always validate arrester specifications against local standards (IEC/IEEE) and environmental conditions .

References