Alternateur A.R.K6F

Electrical Performance

• Type: Three-phase, brushless, self-excited synchronous alternator with PMG excitation

• Frequency: 50 / 60 Hz

• Power Factor: 0.8

• Voltage Range: 380/220V – 480/277V (configurable in star, delta, or parallel star)

• 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: 95.1–95.9% depending on frequency and load

• Overload Capacity: 110% for one hour in a six-hour operation cycle

• Telephone Harmonic Factor (THF): <2%

• Telephone Interference Factor (TIF): <50

• Short Circuit Ratio (1/Xd): 0.17 typical

• Power Ratings (Winding 311):

  • 50 Hz: 950–1313 kVA (Efficiency 95.4–95.9%)

  • 60 Hz: 1050–1575 kVA (Efficiency 95.3–95.5%)

• Reactances (Per Unit at Rated kVA):

  • Xd (Synchronous): 2.33–3.20

  • X’d (Transient): 0.18–0.23

  • X’’d (Subtransient): 0.07–0.08

  • Xq (Quadrature): 1.37–1.88

  • X’’q (Quadrature Subtransient): 0.20–0.26

  • X₂ (Negative Sequence): 0.16–0.22

  • X₀ (Zero Sequence): 0.08–0.09

  • Leakage Reactance (XL): 0.02–0.03

• Time Constants:

  • Transient (T’d): 0.185 s

  • Subtransient (T’’d): 0.025 s

  • Armature (Ta): 0.03 s

  • Open Circuit Field (T’do): 3.40 s

Construction & Design

• Insulation Class: H (125°C rise at 40°C ambient)

• Protection: IP23 (optional IP44 with 5–10% power derating)

• Cooling: Self-ventilated air cooling system

  • 50 Hz: 1.614 m³/s (3420 cfm)

  • 60 Hz: 1.961 m³/s (4156 cfm)

• Frame: Rigid steel structure with cast aluminum front and rear covers

• Stator: Double-layer winding with 2/3 pitch design eliminating 3rd, 9th, and 15th harmonics

• Rotor: Damped rotor dynamically balanced per BS6861 standards

• Bearings:

  • Drive End: 6224 (sealed-for-life ball bearing)

  • Non-Drive End: 6317 (sealed-for-life ball bearing)

• Overspeed Capability: 120% of rated speed (2250 rpm)

• Leads: 12 reconnectable leads (star, delta, or parallel star)

• Inertia (WR²): 25.98–26.52 kg·m²

• Winding Resistance:

  • Stator: 0.002 Ω/phase (22°C, star connection)

  • Rotor: 1.59 Ω (22°C)

Dimensions & Weight

• Rotor Weight: 1093–1110 kg

• Stator Weight: 1294 kg

• Complete Alternator Weight: 2541–2622 kg

• Shipping Weight (Crated): 2581–2660 kg

• Packing Dimensions: 194 × 92 × 147 cm

Regulation & Control

• Excitation System: PMG excitation with brushless AVR

• AVR Models: MX341 (standard), optional SX440, SX460, AS440, MX321

• Voltage Regulation Accuracy: ±1.0%

• Parallel Operation: Supported (AVR-dependent)

• Protection Features:

  • Stator winding and bearing overheat protection

  • Anti-condensation heater (optional)

  • Low-speed voltage drop protection

• RFI Suppression: Complies with BS EN 61000-6-2 & 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 System

Environmental Parameters

• Operating Temperature: –15°C to +40°C

• Relative Humidity: Up to 95% (non-condensing)

• Altitude: Up to 1000 m without derating

• Cooling Air Requirement: 1.614–1.961 m³/s depending on frequency

• Noise & Vibration: Balanced to BS6861 mechanical standards

Performance Summary

• Efficiency Range: 95.1–95.9%

• Voltage Dip (Transient Load): ≤25% at 0.8 PF

• Recovery Time: <0.5 seconds

• Locked Rotor Motor Starting: >300% rated current

• Applications: Prime power, standby, rental, telecom, mobile, railway, refrigeration, and lighting tower generator systems