Stator earth fault protection for Generators by 20Hz Injection method
Stator earth fault protection for Generators by 20Hz Injection method
The 100% stator earth fault protection system is based on a sub-harmonic injection principle. To implement a 100 % stator earth fault protection system a 20Hz current is injected into the generator star point. The 20Hz generator SGEN-1001 is used in combination with the Band Pass Filter SBPF-1001 in the Stator Earth fault protection. The injection can be performed by connecting the SGEN-1001 and the SBPF-1001 to the load resistor of an earthing or neutral transformer. If an earth fault occurs in the generator star point, the 20Hz current flows through the fault resistance. From the driving voltage and the fault current, the protective relay determines the fault resistance.
Features
- 100 % stator earth fault protection based on subharmonic injection
- Detectsstator earth faults when the generator is offline
- Provides a wide range of fault resistance coverage
- Low-cost unit with high performance
- Plug and Play System
Applications
- Generators
Specifications
20Hz GENERATOR SPECIFICATION
| Power Supply | |
| Supply Voltage | 85 to 260V AC, 1φ, (47Hz to 63Hz) or 120V to 370V DC |
| System Status | |
| LED | Power & Signal |
| Alarm | PFC contact |
| Output Signal | |
| Output Voltage | 50V Peak to peak +10%, Rectangular |
| Output Current | 5A continuously |
| Output Frequency | 20Hz +5% |
| Efficiency | 85% |
| Environment | |
| Operating Temp | 0°to 55°C |
| Humidity | 93% Non-Condensing |
| Cooling | Passively Cooled |
| Mechanical | |
| Dimension | 482mm x 173mm x 245mm +5mm |
| Enclosure | Panel/Table Top Mountable |
| Protection Class | IP20 |
| Test | |
| Burn-in Test | IEC 60068-2-78 |
| Vibration Test | IEC 60068-2-6 |
| Shock Test | IEC 60068-2-27 |
| Seismic Test | IEC 60068-3-3 |
20Hz BANDPASS FILTERÂ SPECIFICATION
| Input Signal | |
| Frequency | 20Hz +5% |
| Voltage | 50V +10%, Rectangular |
| Output Signal | |
| Output Voltage | Min 25VÂ RMS without Load |
| Output Current | 5A continuously |
| Output Frequency | 20Hz +5% |
| Withstand voltage | 245V AC at 50Hz (NGT V) |
| The impedance at the centre frequency | <5Ω @ 20Hz |
| The impedance at System frequency | >50Ω @ 50Hz |
| Environment | |
| Operating Temp | 0°to 55°C |
| Humidity | 93% Non-Condensing |
| Cooling | Passively Cooled |
| Mechanical | |
| Dimension | 482mm x 173mm x 245mm +5mm |
| Enclosure | Panel/Table Top Mountable |
| Protection Class | IP20 |
| Test | |
| Burn-in Test | IEC 60068-2-78 |
| Vibration Test | IEC 60068-2-6 |
| Shock Test | IEC 60068-2-27 |
| Seismic Test | IEC 60068-3-3 |
