Neutral Grounding Arc Suppression Coils

Neutral Grounding Arc Suppression System (Peterson Coil or Fault neutralizer) are mainly used in power systems to suppress ground arcs and various resonance phenomena. A ground arc occurs when a single-phase-to-ground fault generates a power-frequency arc at the fault point. The fault currentis relatively small and can easily extinguish at the voltage zero crossing, but it may reignite repeatedly due to the accumulation of system capacitive charges. This intermittent arcing to ground can induce overvoltages severaltimes higher than the rated value, posing serious threats to the insulation of transformers, instrument transformers, and surge arresters. 

Ferroresonance, on the other hand, is a nonlinear resonance phenomenon caused by the interaction between the nonlinear characteristics of a voltage transformer or power transformer core and system capacitance. It is characterized by abnormal rises in voltage and current, often accompanied by noise and overheating, and may lead to the burnout of voltage transformers. Harmonicresonance arises when harmonic sources in the power system, such as rectifiers and frequency converters, interact with system inductance and capacitance parameters, amplifying certain harmonic voltages or currents. This can cause overheating of capacitors and cables, maloperation of protection devices, and deterioration of power quality.

The hazard of ground arcs lies in overvoltage generation and insulation damage; the hazard of ferroresonance lies in equipment failure and system instability; and the hazard of harmonic resonance lies in intensified overheating and reduced power quality.To address the frequent occurrence of arc faults and resonance phenomena (such as ferroresonance and harmonic resonance) in small-current grounding systems.ORION Resistor has developed the OR-ASRD Neutral Grounding Arc Suppression and Harmonic Elimination System. This device integrates microcomputer control, overvoltage protection, and vacuum high-voltage switching technologies to form a fully automated protection system. It is specifically designed for non-effectively grounded neutral systems up to 35 kV,capable of reliably limiting lightning overvoltages,switching overvoltages, resonance overvoltages, and arc-grounding overvoltages.

Working Principle

Arc Suppression: The OR-ASRD suppresses intermittent arc-grounding faults by limiting the recovery voltage of the faulted phase and its rate of rise, thereby rapidly extinguishing the arc.Resonance Elimination: For nonlinear resonance faults, the device eliminates ferroresonance by short-circuiting the open-delta winding of bus-mounted PTs, effectively damping oscillations. 

Fault Management: The system provides precise fault line selection and tripping functions, enabling accurate fault location and rapid isolation, which significantly enhances system safety and power supply reliability.

ORION currently offers two types of arc suppression coil systems.

The first type is the Magnetic-biasing type, and the second is the Vacuum on-load tap-changing type.

The magnetic-biasing type adjusts the inductance by changing the magnetic permeability of the core through excitation current control. It has no mechanical contacts, offering fast response and long service life, although the regulation accuracy is relatively lower.

The vacuum on-load tap-changing arc suppression coil relies on mechanical tap switching with a vacuum interrupter. It provides high adjustment accuracy and a wide inductance range, but it has mechanical wear, slower response, and requires periodic maintenance.

Magnetic-Biasing Arc Suppression Coil Wiring Diagram

Vacuum On-Load Tap-Changing Arc Suppression Coil Wiring Diagram

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Functional Features

Overvoltage Protection: Limits lightning, switching, and interphase overvoltages.

Arc-Grounding Suppression: Replaces arc suppression coils, eliminates intermittent arc-grounding faults, and reduces arc overvoltages.

Ground Fault Identification: Distinguishes arc-grounding, high-resistance grounding, and metallic grounding; records up to 20 fault events permanently, even during power loss.

Ferroresonance Suppression: Detects and quickly eliminates PT ferroresonance.

Voltage Monitoring: Can replace conventional PT cabinets, providing continuous voltage measurement.

Feeder Selection: Supports up to 36 feeders, enabling fast and accurate single-phase ground fault identification.

Remote Signaling: Optional binary-coded telemetry.

Alarms: Includes PT primary/secondary disconnection alarm and high-voltage current-limiting fuse failure alarm.

Communication: RS-232/RS-485 ports available for integration with SCADA or upper-level systems.

Applications

The OR-ASRD cabinet is widely applicable in distribution networks up to 35 kV with non-effectively grounded neutrals, serving

 industries such as power, metallurgy, petrochemicals, coal, and oil.

Operating ConditionsAmbient Temperature: -25℃ to +55℃

• Atmospheric Pressure: 80–110 kPa

• Ambient Humidity: Monthly average maximum relative humidity below 95%, no condensation on the cabinet surface; free from corrosive gases or severe dust and mold that could damage metal or insulation; no flammable or explosive substances present.

Ordering Information

• Please specify the system voltage and rated current when placing an order.

Standard Dimensions of ASRD

• 6 kV / 10 kV: 1000 × 1500 × 2300 mm (W × D × H)

• 35 kV: 2000 × 2400 × 2930 mm (W × D × H)

• Custom Dimensions: Can also be specially manufactured according to user requirements.

Operating Conditions

• Ambient Temperature: -25℃ to +55℃

• Atmospheric Pressure: 80–110 kPa

• Ambient Humidity: Monthly average maximum relative humidity below 95%, no condensation on the cabinet surface; free from corrosive gases or severe dust and mold that could damage metal or insulation; no flammable or explosive substances present.

Ordering Information

• Please specify the system voltage and rated current when placing an order.

  
  

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