L’**A.R.K4FG** est un alternateur triphasé sans balais conçu pour un fonctionnement industriel continu. Grâce à son **système PMG** et son **AVR MX341**, il offre une excellente stabilité de tension (±1 %), une faible distorsion harmonique (**THD < 5 %**) et une efficacité élevée jusqu’à **94,2 %**, idéal pour les groupes électrogènes **prime et standby**.
| Système d’excitation | SELF EXCITED |
| A.V.R. | MX341 WITH PMG |
| Régulation de tension à régime établi | ± 1.0 % |
| Court-circuit prolongé | >300% OF RATED CURRENT |
| Facteur de puissance nominal | 0.8 |
Electrical Performance
Type: Three-phase, brushless, self-excited synchronous alternator with PMG excitation
Frequency: 50 / 60 Hz
Power Factor: 0.8
Rated Voltage: 380/220V – 480/277V (configurable in star, delta, or parallel star connection)
Voltage Regulation: ±1.0%
Total Harmonic Distortion (THD): <5% (balanced linear load), <1.5% (no load)
Sustained Short Circuit Current: >300% of rated current for 10 seconds
Efficiency: Up to 94.2% at full load
Telephone Harmonic Factor (THF): <2%
Telephone Interference Factor (TIF): <50
Short Circuit Ratio (1/Xd): 0.09 typical
Overload Capacity: 110% for one hour in six-hour cycles
Reactances (Per Unit at Rated kVA):
Xd (Synchronous): 2.17–3.21
X’d (Transient): 0.12–0.17
X’’d (Subtransient): 0.09–0.12
Xq (Quadrature): 1.66–2.84
X’’q (Quadrature Subtransient): 0.25–0.39
X₂ (Negative Sequence): 0.16–0.26
X₀ (Zero Sequence): 0.06–0.08
Time Constants:
Transient (T’d): 0.08 s
Subtransient (T’’d): 0.019 s
Armature (Ta): 0.018 s
Open Circuit Field (T’do): 1.7 s
Waveform Distortion: <1.5% (no load), <5% (balanced linear load)
Construction & Design
Insulation Class: H (125°C rise at 40°C ambient)
Protection: IP23
Cooling System: Self-ventilated air cooling (0.486 m³/s @50Hz, 0.580 m³/s @60Hz)
Frame Structure: Rigid steel frame with cast aluminum front and rear covers
Winding: Double-layer stator winding, 2/3 pitch design to eliminate triple harmonics
Rotor: Damped rotor with dynamic balancing (BS6861 compliant)
Bearings:
Drive End: 6317 (sealed-for-life ball bearing)
Non-Drive End: 6314 (sealed-for-life ball bearing)
Overspeed Capability: 120% of rated speed (2250 rpm)
Leads: 12 reconnectable leads (star, delta, parallel)
Moment of Inertia (WR²):
Single Bearing: 5.43 kg·m²
Double Bearing: 5.23 kg·m²
Weight:
Complete Alternator: 1160 kg
Rotor: 463 kg
Stator: 535 kg
Shipping Weight: 1775 kg (50Hz) / 1780 kg (60Hz)
Packing Dimensions: 155 × 87 × 107 cm (50Hz) / 156 × 87 × 107 cm (60Hz)
Regulation & Control
Excitation System: PMG excitation with brushless design
AVR Model: MX341 (standard), optional SX460, SX440, AS440, MX321
Voltage Regulation Accuracy: ±1.0%
Parallel Operation: Supported (AVR-dependent)
Low-Speed Voltage Drop Protection: Standard feature
RFI Suppression: Complies with BS EN 61000-6-2 and BS EN 61000-6-4, VDE 0875G/N
Standards Compliance: IEC60034, GB755, BS5000, NEMA MG1-22, CSA C22.2-100, AS1359
Certification: ISO9001 quality management
Environmental Parameters
Operating Temperature: –15°C to +40°C
Relative Humidity: Up to 95% (non-condensing)
Altitude: Up to 1000 m without derating
Noise & Vibration: Balanced per BS6861 standards
Cooling Air Requirement: 0.486 m³/s @50Hz, 0.580 m³/s @60Hz
Performance Summary
Efficiency Range: 93.5–94.2% across load range
Voltage Dip (Transient Load): ≤25% at 0.8 PF
Recovery Time: <0.5 seconds
Locked Rotor Motor Starting: >300% of rated current
Applications: Prime power, standby, rental, telecom, mobile power, refrigeration, and railway generator systems
