Why Run Generators in Parallel?
For offshore drilling platforms, remote industrial sites, and critical facilities, parallel operation of multiple diesel generator sets provides flexibility, reliability, and efficiency that a single large unit cannot match.
Key Benefits
- Modular capacity: Add or remove units based on load demand
- Improved efficiency: Run generators at optimal load (70-80% of rated capacity)
- N+1 redundancy: Continue operation even if one unit fails
- Maintenance flexibility: Service individual units without total shutdown
- Lower initial cost: Install base capacity now, expand later
Technical Requirements for Parallel Operation
Successful paralleling requires matching these parameters across all units:
- Voltage: Within ±1% (typically ±4V for 400V systems)
- Frequency: Within ±0.2 Hz
- Phase sequence: Must be identical (ABC or CBA)
- Phase angle: Within ±10 electrical degrees
Control Systems
Modern parallel systems use digital controllers with load-sharing capability:
- Isochronous mode: Equal frequency, proportional load sharing
- Droop mode: Slight frequency drop under load (3-5% droop typical)
- Base load + peak mode: One unit carries base load, others handle peaks
Jichai Engines for Parallel Applications
Hailong supplies Jichai 190 and 6190 series diesel engines optimized for generator paralleling:
- Electronic governors with ±0.25% frequency regulation
- Fast load response (10% load step in under 3 seconds)
- Harmonic damping for stable parallel operation
- CAN bus integration for remote monitoring
Installation Considerations
When designing a parallel generator system:
- Size conductors for combined short-circuit current
- Install synchronizing panel with synchroscope or LED indicators
- Provide adequate cooling for all units
- Use identical fuel specifications across all generators
Need help specifying a parallel generator system? Contact us at +86-532-66090318 or nora@qdhailong.com.