Perkins is developing a variety of hybrid engines to match power to task

hybrid engine Perkins
Perkins’ hybrid-hydraulic engine.
By Bill Tremblay

In the off-highway segment, one hybrid engine design likely won’t be the ideal fit for all heavy equipment.

That’s why Perkins is introducing Power 3.0, a range of hybrid power solutions for original equipment manufacturers (OEMs).

Perkins has created a dedicated team and new technologies focused on hybrid and electric power solutions that are relevant and adapted to meet the specific needs of construction machines.

Following a significant investment in hybrid engines and electrification research, Perkins unveiled a range of technologies designed to add value to OEMs as they design the next generation of off-highway machines.

“There’s a lot of interest in the market around what happens next,” said Oliver Lythgoe, product concept marketing at Perkins. 

A new engine era

Perkins categorizes engines in three sections. The 1.0 segment representing the classic diesel engines that were produced between 1930 and 2000. The 2.0 segment represents the emissions era where all research and development resources were tasked with making engines cleaner. 

“In that (2.0) period, particulate matter and NOx were reduced by 95 per cent,” Lythgoe said. “It’s a massive change in what comes out of the exhaust of an engine.”

Now, Perkins is focusing on the third incarnation of diesel engines. Power 3.0 will see research and development focus on how to create an engine that is focused on sustainability, as well as capable of delivering more productivity while consuming less fuel. 

“Power 3.0 is the next stage,” Lythgoe said. “The hybrids and electrics will be part of that story.”

The hybrid-electric, hybrid-mechanical and hybrid-hydraulic power technologies complement Perkins’ existing 0.5 to 18 litre range of diesel engines, ensuring OEMs and their customers benefit from machines that are more productive, quieter and have lower fuel consumption, whatever power solution they select.

“Through our close technical collaboration with our OEMs, and using a huge amount of real field data, we develop solutions that are truly relevant to the construction sector,” said Matt Coleman, product director at Perkins.

Perkins hybrid-mechanical engine.

Hybrid feasibility 

The notion of using the same hybrid tech that is found on-road on passenger vehicles for construction equipment isn’t feasible. 

“The operating cycles are so different in construction than what’s on highway,” Lythgoe said. “There’s no traffic lights. If you have a dozer travelling at 4km/h you’re not going to get much (energy regeneration) by braking.” 

With access to millions of hours of machine operating data, Perkins has identified the operating cycles of real construction machines vary from one application to another, and as machine size increases.

The duty cycles, operating conditions and packaging constraints for off-highway machines drive the need for specific configurations that are highly customized to the individual application.

“There isn’t one solution that fits all machines,” Coleman said. “Perkins is establishing itself as an integrator with multiple hybrid and electric power technologies.

“The difference between off-highway machines in operating conditions means that there is limited, if any, value in technology transfers from other sectors such as automotive, truck or marine.”

At bauma 2019, Perkins highlighted three hybrid power solutions through three engines, all at 75 kW (100 hp). To demonstrate modularity and flexibility, all three hybrid solutions are based on the Perkins Syncro 2.8 litre. The three hybrid engine technologies introduced are:  

Hybrid-electric

 There are several ways to incorporate the electric motor or generator, with Perkins preferred arrangement delivering fuel saving benefits while moderating the installation impact and minimizing the cost impact on the machine. The flexibility of the system provides opportunities for further efficiency and functionality improvements in the whole machine through use of 48-volt electrics.

“This takes energy and stores it in lithium ion batteries. You can store a lot of energy, but you can only release it quite slowly,” Lythgoe said. 

“It also takes a lot of space, and honestly its quite expensive.” 

Hybrid-mechanical

This stores energy in a high-speed flywheel, which can be delivered back to the machine. 

This is particularly useful in hybridizing machines that run a cyclic operation and need very intense bursts of additional power. Apart from the very quick energy release, the advantage over hybrid-electric is in installation size.

“Your storage is next to nothing. It’s much easier to fit into a machine and you can really see a sharp punch of energy,” Lythgoe said. 

“It fades out over time, but it would work well in a machine that’s doing something cyclical, like loading a truck. Lots of off highway machines do cyclical things.” 

Hybrid-hydraulic

This stores energy in hydraulic accumulators. In some machines, this can be the most practical and cost-effective hybrid solution as it easily integrates into existing machine hydraulic systems. Software and integration of machine systems are key to achieving great savings from this technology.

“You store energy as pressurized hydraulic fluid, and you can release that as its needed,” Lythgoe said. “It’s good for machines that have a lot of hydraulics, like excavators or wheel loaders.”

The hybrid options are just three of eight different engine technologies Perkins is developing. 

“We see spaces for all of those eight,” Lythgoe said, noting other tech is in different stages of development. “What we’re saying to our customers, the OEMs, is this is a complicated space. Don’t just have the first hybrid that comes into your head.”

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