HYXHG series Intelligent Arc Suppression Device (for 3–35 kV Ungrounded Systems)

Application Scope

1. Applicable to 3–35 kV medium-voltage power systems.
2. Suitable for ungrounded neutral systems, resonant grounded systems (via arc suppression coil), and high-resistance grounded systems.
3. Suitable for networks dominated by cable lines, mixed cable and overhead lines, or overhead line-dominated networks.

Basic Functions

• During normal operation, the device monitors PT signals and provides system alarm, trip, and lockout functions. It includes single-phase ground fault detection, transition fault point location, arc suppression, harmonic suppression, over-voltage alarm, and fault recording functions.
• Records parameters such as fault time, fault type, fault phase, line voltage, and neutral current, facilitating fault analysis.
• When a single-phase ground fault occurs, the device responds within 30 ms, determines fault type, and automatically selects arc suppression measures (arc suppression coil, grounding resistance, or other methods).
• Suppresses sustained arc grounding, reducing the risk of insulation breakdown, short circuits, or equipment explosions.
• Provides PT disconnection monitoring, preventing false actions due to PT failures.
• Features PTK smart switching technology, which suppresses sustained overvoltage caused by arc-ground faults, protecting equipment safety.
• Supports RS-485 communication and MODBUS protocol for data acquisition and remote monitoring.

Additional Functions

• Can be configured with an automatic neutral selection circuit.
• Works with HYXL low-current grounding selection device to improve fault detection accuracy.
• Optional “elimination” mode: special technology discharges residual charge and prevents ferroresonance damage to PTs.
• User-customizable additional harmonic suppression modules are available.

Working Principle

1. The controller continuously monitors secondary voltages of PTs in open-delta connection.
2. When a single-phase ground fault occurs, changes in PT secondary voltages (Ua, Ub, Uc) are analyzed to determine the fault type.
3. For metallic ground faults, the device quickly isolates the fault point, issues trip signals, and protects equipment and personnel.
4. For intermittent arc-ground faults, the system detects fault characteristics and automatically operates the suppression unit within 30–40 ms, preventing overvoltage escalation.
5. For resonant grounded systems, the device suppresses transient and steady-state overvoltages, ensuring safe system recovery.

Main Features