Technical Requirements for Cummins Diesel Generator Set Parallel System

Technical Requirements for Cummins Diesel Generator Set Parallel System

(1) Multi-Unit Parallel Operation Functionality

• Two or more generator sets must support parallel operation.
• Multiple generators running in parallel must have automatic/manual start and automatic/manual stop functions, which operate independently without interference. 
• The system must support automatic start + manual stop operation.
• The auto-start mode should be adjustable based on different grid power system conditions to meet operational and maintenance requirements.

(2) Parallel Control Display Panel (Chinese Language)

• The display must show the main system and generator status in Chinese, including: 
• Single-line diagram indicating equipment status. 
• Real-time operating status of each generator.
• Alarms, warnings, and fault status for each generator.
• Operation logs and fault records for each generator.
• System protection functions.
• Hot standby redundancy capability.

(3) Stable Parallel Operation (50%-100% Load Range)

• Parallel units must operate stably within 50%-100% of total rated power.
• Smooth active & reactive power transfer must be ensured.
• Power distribution deviation ≤5% (per GB/T 2820.5-2009).
• Parallel operation must not reduce the rated output capacity of any unit.

(4) Fault Isolation During Parallel Operation

If one generator or its parallel device fails, it must not affect the startup, operation, or monitoring signals of other units.

(5) Redundant Master Control System

• A master control cabinet with hot backup redundancy is required.
• If the primary control module fails, the backup module must take over seamlessly to ensure uninterrupted power supply.

(6) Startup & Synchronization Time (≤60 Seconds)

• From startup command (excluding delay) to full parallel load-bearing: ≤60 seconds.
• Generators must start sequentially.

(7) Grid Power Recovery & Shutdown Sequence

• Upon grid power restoration, the system must: 
• Transfer loads back to the grid after an adjustable delay.
• Let generators run no-load for 2-10 minutes (adjustable) before shutdown. 
• Shut down generators sequentially.

(8) Load Demand & Unit Shedding/Adding Logic

• After grid failure, all units run in parallel for 2-10 minutes (adjustable), then:
• If load <50% of total rated power, one unit automatically stops.
• Repeat until no further reduction is possible.
• During operation, if load >50% of running units’ capacity, a standby unit auto-starts and synchronizes.

(9) Hot Backup & Scalability

• The parallel control system must support hot backup and future expansion without compromising reliability.
• Reserved expansion interfaces must be provided.