Integration of a Dual-Mode SI-HCCI Engine Into Various Vehicle Architectures

Author(s):  
Benjamin J. Lawler ◽  
Zoran S. Filipi

A simulation study was performed to evaluate the potential fuel economy benefits of integrating a dual-mode SI-HCCI engine into various vehicle architectures. The vehicle configurations that were considered include a conventional vehicle, a mild parallel hybrid, and a power-split hybrid. The three configurations were modeled and compared in detail for a given engine size (2.0 L for the conventional vehicle, 2.0 L for the mild parallel, and 1.5 L for the power-split) over the EPA UDDS (city) and Highway cycles. The results show that the dual-mode engine in the conventional vehicle offers a modest gain in vehicle fuel economy of approximately 5–7%. The gains were modest due to an advanced 6-speed transmission and a practically-based shift schedule, with which only 30% of the operating points were in the HCCI range for the city cycle and 56% for the highway cycle. The mild parallel hybrid achieved 32% better fuel economy than the conventional vehicle, both with SI engines. For the dual-mode engine in the mild parallel hybrid, a specific control strategy was used to manipulate engine operation in an attempt to minimize the number of engine mode transitions and maximize the time spent in HCCI. The parallel hybrid with the dual-mode engine and modified control strategy provides dramatic improvements of up to 48% in city driving, demonstrating that the addition of HCCI has a more significant effect with parallel hybrids than conventional vehicles. The power-split hybrid simulation showed that adding a dual-mode engine had an insignificant effect on vehicle fuel economy, mostly due to the ability of the planetary gear set to act as an e-CVT and keep the engine at relatively high loads. Finally, a systematic study of engine sizing provides guidelines for selecting the best option for a given vehicle application by characterizing the vehicle level interactions, and their effect on fuel economy, over an engine displacement sweep.

Author(s):  
Benjamin J. Lawler ◽  
Zoran S. Filipi

A simulation study was performed to evaluate the potential fuel economy benefits of integrating a dual-mode SI-HCCI engine into various vehicle architectures. The vehicle configurations that were considered include a conventional vehicle and a mild parallel hybrid electric vehicle. The two configurations were modeled and compared in detail for a given engine size (2.0 L) over the EPA UDDS (city) and highway cycles. The results show that the dual-mode engine in the conventional vehicle offers a modest gain in vehicle fuel economy of approximately 5–7%. The gains were modest because the baseline (the SI engine in the conventional vehicle) is relatively advanced with a six-speed automated manual transmission. The mild parallel hybrid with the SI engine achieved 32% better fuel economy than the conventional vehicle in the city, but only 6% on the highway. For the dual-mode engine in the mild parallel hybrid, a specific control strategy was used to manipulate engine operation in an attempt to minimize the number of engine mode transitions and maximize the time spent in HCCI. The parallel hybrid with the dual-mode engine and modified control strategy provides dramatic improvements of up to 48% for city driving, demonstrating that the addition of HCCI has a more significant impact with mild parallel hybrids than with conventional vehicles. Finally, a systematic study of engine sizing provides guidelines for selecting the best option for a given vehicle application.


Author(s):  
Mateus Bertolin ◽  
Andrea Vacca

Abstract This paper proposes a novel hybrid power-split transmission to drive hydraulic implements in construction machinery. The highly efficient power-split hybrid transmission is combined with displacement controlled (DC) actuators to eliminate throttling losses within the hydraulic system and achieve higher fuel savings. The architecture design, sizing and power management are addressed. Simulation results considering a realistic truck-loading cycle on a mini excavator demonstrate the feasibility of the idea. A systematic comparison between the proposed system and the previously developed series-parallel hybrid is also carried out. The paper compares engine operation and fuel consumption of the previously mentioned hybrid system with the original non-hybrid load-sensing machine. It is shown that by implementing an efficient engine operation control, the proposed system can achieve up to 60.2% improvement in fuel consumption when compared to the original machine and consume 11.8% less than the previously developed series-parallel hybrid with DC actuation. Other advantages of the proposed solution include a much steadier engine operation, which opens to the possibility of designing an engine for optimal consumption and emissions at a single operating point as well as greatly reduce pollutant emissions. A steadier prime mover operation should also benefit fully electric machines, as the battery would not be stressed with heavy transients.


Author(s):  
Shima Nazari ◽  
Jason Siegel ◽  
Robert Middleton ◽  
Anna Stefanopoulou

This work studies a novel low voltage (<60 V) hybrid system that supports engine boosting and downsizing in addition to start-stop, regenerative braking, and constrained torque assist/regeneration. The hybrid power split supercharger (PSS) shares a 9 kW motor between supercharging the engine or providing hybrid functionalities through a planetary gear set, a brake and a bypass valve. The PSS operation is limited to only one of the parallel hybrid or boosting modes at a time, necessitating a highly optimized decision making algorithm to select the device mode and power split ratio. In this work an adaptive equivalent consumption minimization strategy (A-ECMS) is developed for energy management of the PSS. The A-ECMS effectiveness is compared against a dynamic programming (DP) solution with full drive cycle preview through hardware-in-the-loop experiments on an engine dynamometer testbed. The experiments show that the PSS with A-ECMS reduces a vehicle fuel consumption by 18.4% over standard FTP75 cycle compared to a baseline turbocharged engine, while global optimal DP solution decreases the fuel consumption by 22.8% compared to baseline.


Author(s):  
Mohsen Esfahanian ◽  
Ahmad Khanipour ◽  
Ali Nabi ◽  
Amir Mohammad Fazeli ◽  
Meisam Amiri

Hybridization of conventional vehicles is considered an important step to achieve high fuel economy and low emissions. In this study, principle considerations involved in a hybridizing process are discussed and consequently, a sequential approach for designing hybrid components for both series and parallel configurations has been introduced. The so called approach has then been applied to one of the productions of Iran-Khodro Company called SAMAND. Having designed the hybrid components, the conventional SAMAND and its series and parallel hybrid configurations were defined and evaluated using the ADvanced VehIcle SimulatOR (ADVISOR) software. It is observed that compared to the conventional vehicle, a reduction in fuel consumption by about 51% in the series configuration and about 34% in the optimized parallel configuration is achievable.


Author(s):  
Minkuk Kang ◽  
Hyunjun Kim ◽  
Dongsuk Kum

Nowadays, power-split hybrid electric vehicles (PS-HEV) are very popular mainly thanks to the success of Toyota Prius. Despite their superior performance, the design and control of PS-HEVs are non-trivial due to the large number of design candidates and the complex control problems. For instance, there exist twelve ways to connect the four components (two motor/generators, an engine, and a driving wheel) with a single planetary gear-set (PG), and the number increases to 1152 possible configurations when using two PGs. Moreover, if we consider the final drive (FD) and PG ratios as design variables, finding the best design becomes intractable. In this study, we introduce a simple yet powerful way to find the optimal designs of single PG PS-HEVs. The suggested method consists of two parts — full-load analysis and light-load analysis. The full-load analysis computes 0–100kph times to evaluate acceleration performance of all designs using instantaneous optimization approach. The light-load analysis evaluates the fuel economy of selected designs (designs with acceptable acceleration performance) using equivalent consumption minimization strategy (ECMS). Note that the sun-to-ring (SR) gear ratio and the FD ratio are considered design variables, and thus one can see how fuel economy and acceleration performance of each configuration vary with SR and FD ratios. Based on these analyses, the optimal design that balances full-load and light-load performances can be selected.


2018 ◽  
Vol 10 (1) ◽  
pp. 168781401774773 ◽  
Author(s):  
Chang Lyu ◽  
Zhao Yanqing ◽  
Lyu Meng

In hydraulic mechanical transmission loaders, a hydraulic torque converter can prevent an engine from stalling due to overloading of the loader during the spading process; however, the hydraulic torque converter also reduces the loader’s fuel economy because of its low transmission efficiency. To address this issue, the study designs an output-power-split transmission system that is applied to a hybrid loader. The designed transmission system removes the hydraulic torque converter in the power transmission system of a traditional loader and adopts a planetary gear set with a compact structure as the dynamic coupling element, thus allowing the output power of the loader to be split transmitted. During shoveling, the loader power-split transmission system based on a planetary gear set can prevent the motor from plugging and over-burning under conditions that ensure that the traction does not decrease. In addition, the transmission efficiency and loader fuel economy are higher in the proposed transmission system than in the power transmission system of a traditional loader. The test results show that the transmission efficiency of the designed system was 13.2% higher than that of the traditional hydraulic mechanical transmission loader.


Author(s):  
Pier Giuseppe Anselma ◽  
Yi Huo ◽  
Joel Roeleveld ◽  
Ali Emadi ◽  
Giovanni Belingardi

This work aims at presenting a design methodology capable of modeling, generating, and testing a large number of multimode power split hybrid electric vehicle transmission designs in a relatively short period of time. Design parameters include the planetary gear ratios, the final drive ratio, the configuration of hookups to link the hybrid powertrain components to the planetary gear sets and the locations of clutch connections between different nodes of the planetary gear sets. The system modeling approach is first presented, including formulations for each component (the vehicle and road load, the engine, the motor/generators and the battery). A rapid and automated modeling procedure is proposed for hybrid electric vehicle transmissions including multiple planetary gear sets and clutch connections. Two algorithms are subsequently presented that enable fast evaluation of fuel economy and acceleration performance of hybrid electric vehicle transmission designs, namely the enhanced Power-Weighted Efficiency Analysis for Rapid Sizing and the Rapid Efficiency-based Launching Performance Analysis algorithms. The developed design methodology is tested by first modeling and evaluating three hybrid electric vehicle designs from the state-of-art. Later, an investigation for optimal designs that can ameliorate the examined benchmarks is performed. Several millions of design options are rapidly generated and tested using the proposed procedure. The methodology is proved effective by quickly coming up with two sub-optimal designs. Fuel economy and acceleration performance are improved by 5.56% and 40.56%, respectively, compared to the corresponding best benchmarks.


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