Next Generation PowerCommand Controls For New Cummins Gen-Sets

Diesel Progress North American Edition, May, 2001

Cummins Power Generation has developed a new family of diesel generator sets designed to offer improved fuel economy, lower emissions and improved control and diagnostic capability. The new DFE series gen-sets are available in ratings of 300 kW (DFEG), 400 kW (DEE-H), 450 kW (DFE-J) and 500 kW (DFE-K) at either 50 or 60 Hz and are suitable for standby or prime power applications, the company said.

"These generator sets use the new Cummins QSX 15 truck engine, which has greater power output per cubic inch of displacement than previous designs," said Pat Murphy program management and product planning for the Minneapolis, Minn., company. "It's also a full authority electronically controlled engine, which means excellent fuel economy and reliability."

Murphy also said the 15 L, turbo charged and air-to-air charge-air cooled engine provides significant emissions reductions, allowing them to meet all current EPA Tier 1 and Tier 2 non-mad requirements.

The engine package features G&O charge-air cooler/radiators, Fleetguard oil filters, Donaldson radiators and Nelson mufflers. The engine drives a single-bearing alternator coupled directly to the engine flywheel with flexible discs for drivetrain reliability and durability. Two thirds pitch armature windings minimize output voltage third-order harmonic content, the company said.

A Permanent Magnet Generator (PMG) excitation system limits voltage dip during transient load application, sustains three-phase short circuit current at approximately three times rated for up to 10 seconds and is resistant to harmful effects of harmonics generated by nonlinear loads. The alternator is also suitable for applications containing large motors or sensitive electronics. Several alternator sizes are available to meet individual application needs.

The DFE series gen-sets also incorporate the latest generation of the company's PowerCommand controls. The system, which was initially available on the company's 2MW DQKC gen-sets, provides in excess of 200 diagnostic monitoring functions and offers plug-and-play interoperability with most building automation and electric utility SCADA systems.

"In generation paralleling applications, PowerCommand gen-sets offer near instantaneous synchronization of multiple gen-sets and the precise load sharing that are critical in emergency standby operations," said Gary Olson, technical counsel at Cummins Power Generation. "Reliability is enhanced because PowerCommand logically interacts with the engine and alternator to both protect the equipment and minimize nuisance failures. Like previous versions of PowerCommand, it excels in networking and paralleling applications where the gen-set must perform as part of a coordinated system."

The DFE series gen-sets with the newest PowerCommand control are LonMark compliant and also meet the new UL2200 safety standard that covers the complete stationary engine generator assembly rather than individual components.

"Prior to UL2200, some of the subcomponents of a generator set were individually compliant to separate UL standards, such as fuel tanks, alternators and control panels," said Jim Iverson, Cummins Power Generation's technical marketing manager. "This new standard covers the entire operational gen-set and gives electrical inspectors the highest level of confidence that the complete generator set design has undergone an extremely thorough review by UL. This should reduce the time and effort involved in inspecting and approving new generator set installations.

The new standard is initially being applied to commercial diesel gen-sets from 500 kW down to 35 kW, but the company expects that by midyear, all gensets up to 2000 kW will be compliant.

Quiet Diesel Gen-Sets For Marine Applications

Adapting the quiet design features of its RV generator sets along with digital controls from its larger units, Onan recently introduced its first small digital generator set for marine applications. The 4/5 e-QD gen-set, initially unveiled at the Fort Lauderdale Boat Show, is the first in the company's e-QD (electronic quiet diesel) series and is available in 4 kW and 5 kW outputs at 50 and 60 Hz, respectively

New models in the e-QD series available include the 7/9 e-QD, with 7 kW and 9 kW outputs; the 9.5/11.5 e-QD, with 9.5 kW and 11.5 kW outputs; and the 11/13.5 e-QD, with 11 kW and 13.5 kW outputs, at 50 and 60 Hz, respectively

"The e-QDs are the first digital gen-sets really designed for the marine pleasure craft market," said LeAnne Ketelsen, manager, worldwide marine sales and marketing. "The digital controls are highly reliable and bring a new level of information to the user."

The e-QD series' digital electronic control, developed by Onan, provides extensive diagnostic capabilities, which are accessed from the start/stop switch status light mounted on the gen-set's control panel. The control continually monitors gen-set operation and alerts the user to potential problems, such as a blocked water intake system or failed impeller, before overheating occurs. The protection for no raw water flow is a unique, patent-pending feature.