Posted on: 08 December 2017.
It can be argued that there has been very little innovation in propulsion systems for vehicles in the last 20 years. Although engines and gearboxes have become more advanced and efficient, innovation has been limited to improving existing systems.
Internationally, there is pressure from environmental groups, and governments, to reduce harmful emissions from internal-combustion engines and this has mostly resulted in the development of hybrid propulsion systems.
The big drive in personal vehicles is to get to zero emissions through electric engines, but the limitation remains the distance a battery charge can give. Also, to recharge such a bank of batteries takes hours, where it takes minutes to refill the fuel tank on a car or a truck.
Just like with internal-combustion engines, trucks that carry a heavier load need bigger motors and batteries. And this is where there seems to be some interesting developments heading for the market.
Hybrid propulsion systems, typically a combination of an internal-combustion engine and another unit such as an electric motor, have been around for a while. As have engines running on CNG (compressed natural gas). But just like engines running off hydrogen – fuel cells – there is a safety issue around the tanks containing the volatile fuels.
Volvo Trucks has developed a new concept with support from the Swedish Energy Agency. The Volvo Concept Truck is said to reduce fuel costs by as much as 30%. But this is achieved mostly by improving aerodynamics of the rig and reduced weight.
Last year Mercedes-Benz announced the development of their eTruck. This is a solution aimed primarily at the so-called last-mile distribution network. It is a zero-emissions vehicle with a range of 200km per charge. But is not yet clear when they envisage that this truck will be commercially available.
Volkswagen recently announced that its truck and bus division will invest €1,4 billion in new technology, including electric drivetrains. Volkswagen says the e-Delivery, an electric truck, will be manufactured in Brazil in 2020. The company’s MAN and Scania divisions will be supplying electric buses to European cities in 2018 – supplementing their bio-diesel, hybrid and natural-gas offerings.
Tesla, the company that is most successful in producing electric cars, recently announced their electric truck, the Tesla Semi. Elon Musk, the South-African born innovator, announced that the Tesla Semi will have a range of 640km and – even more impressive – will be able to recharge within half an hour.
But, generally, electric trucks would only be used on shorter trips, because there are no recharging stations for such a truck’s batteries.
Although 4 100 electric trucks were sold worldwide in 2016, it does not seem as if we will be seeing any of these innovations locally any time soon. But that can change any moment now, as a locally developed propulsion unit has just finished its final testing phase and results have been validated by the Gerotek Testing Facilities.
Ducere Holdings is the owner of MISER hydraulic hybrid transmission technology, which they say will bring the future to transport.
He says it is no secret that the batteries remain the Achilles heel of any electric vehicle. The world is still waiting for the battery that can hold enough energy and last as long as the vehicle itself.
“And while we wait, any system that can improve – in other words reduce – the current draw from batteries and increase the number of charge/discharge cycles will be welcomed. And we have that system.
“Our current major project and focus, The MISER Hydraulic Hybrid Transmission System, keeps us involved at the forefront of today’s automotive hybrid technology – and that’s where we like to be,” says André Reyneke, managing director.
Their first product onto the market is MISER-HKS, a retrofit hydraulic hybrid transmission, specific for heavy-duty vehicles.
“The MISER technology is a revolutionary new approach to kinetic energy recovery, engine optimisation, and storage and reapplication for any form of vehicle. The system complements various other technologies aimed at dramatically improving fuel consumption, vehicle performance and total cost of ownership – while simultaneously reducing carbon emissions.”
Reyneke says the technology enables more efficient energy recovery and engine optimisation than any competing technology.
“MISER achieves this with a hydraulic solution using a combination of braking-energy recovery, engine optimisation and various modes such as torque summing, regenerative braking and launch assist. This provides an efficient medium for the fast storing and release of energy, while at the same time optimising engine performance by keeping the engine on the ideal brake-specific fuel consumption line.
“The MISER transmission is a hydraulic and mechanical, inﬁnitely variable dual-path energy-transfer system with a sophisticated microprocessor control system. It has fewer energy-ﬂow paths, fewer valves and fewer parasitic losses, such as charge pumps, than any existing hydraulic hybrid systems.”
He says MISER is an enabler of electric vehicles.
“The best electric vehicles are electric-hydraulic hybrids due to its more efficient regenerative-braking abilities along with the launch-assist, reducing peak battery loads.”
Reyneke says the hydraulic system is significantly more efficient than the typical regenerative ability of an electric drive.
“An electric vehicle is about 30% efficient in regenerative braking mode, where our hydraulics achieve around 70% efficiency.”
He says this brings a number of possibilities into play. The more efficient regenerative braking could mean up to a 30% increase in range in a town-drive cycle.
The MISER transmission is a compound-type hybrid drive. In some modes it is a series system (where the engine can charge the storage system with energy for later use) and in other modes it is a parallel system (where the energy is delivered from the engine, or the storage system, or a combination of both). This depends on which of the 13 possible modes the control system selects for the MISER-HTS version.
The MISER system can be installed in one of two ways. The ﬁrst option (recently made available to the marketplace) is the Hybrid Kinetic Energy Recovery System, or HKS for short. It involves the ﬁtment of the energy-recovery components only. Benefits are both regenerative braking and engine optimisation.
The second installation involves the replacement of the vehicle’s original gearbox as well as the ﬁtment of the Hybrid Kinetic Energy Recovery system. This is called the Hybrid Transmission System – HTS. Several additional advantages include savings specifically advantageous in highway-type driving cycles.
“Our pilot project at a long-haul transport client using a heavy-duty truck delivered excellent results with MISER-HKS, showing fuel savings in certain drive cycles in excess of 40%.
“The Gerotek Test Facility performed independent tests on the same truck and their results have confirmed ours, proving the efficiency of our technology.
“We have also started our new project that uses a combination of our hydraulic version and other power sources, specifically aimed at smaller passenger vehicles. We expect the first few vehicles on the road in 2018. We believe that this will be a game changer as it incorporates a new way of thinking.”
Reyneke says they see the immediate market potential of MISER as being aftermarket sales, followed by the new transmission and energy-recovery technology universally ﬁtted to all forms of motorised vehicles and transportation systems over the next eight to ten years.
“Unlike electrical systems that cannot scale due to technology constraints, MISER can comfortably be ﬁtted to a range of vehicles – from a small car up to very large excavator. This gives us a distinct advantage as we can participate in a far wider range of sectors.
“Recent studies have shown that electric vehicles will benefit significantly from using hydraulic hybrids to improve current draw and improve battery charge cycles. While the world’s focus is on pure electric and electric-hybrid vehicles, there is very limited attention on the hydraulic hybrid solution. And this is the ﬁeld in which MISER aims to be the leader,” says Reyneke.