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Continuing research introduced at the 2018 WCX conference, this paper shows the result of simulations where a midsize sedan (1700 kg) fitted with an adaptive cycle engine and a CVT is operated over three standard duty cycles: US06, UDDS, and HWFET, and compared with the results obtained from other engine cycles installed on the same vehicle. Four different engine cycles are compared: conventional 4-stroke, 6-stroke cycle with no air storage, 6-stroke cycle with air storage, and fully adaptive cycle with air storage and a number of strokes determined by instantaneous demand and state of charge of the storage tank. Results show that the fully adaptive engine achieves a better mileage in all scenarios, closely followed by the partially adaptive 6-stroke cycle with storage. Gains over a conventional 4-stroke powerplant range from 3.4 mpg on the HWFET cycle, to 7.6 mpg on the UDDS cycle.

Traditionally, internal combustion engines follow thermodynamic cycles comprising a fixed number of crank revolutions, in order to accommodate compression of the incoming air as well as expansion of the combustion products. With the advent of computer-controlled valve trains, we now have the possibility of detaching compression from expansion events, thus achieving an “adaptive cycle” molded to the performance required of the engine at any given time. The adaptive cycle engine differs from split-cycle engines in that all phases of the cycle take place within the same cylinder, so that in an extreme case the gas contained in all cylinders can be undergoing expansion events, resulting in a large increase in power density over the conventional four-stroke and two-stroke cycles. Key to the adaptive cycle is the addition of a variable-timing “transfer” valve to each cylinder, plus a space for air storage between compression and expansion events.

In order to improve efficiency and increase the operation of electric vehicles, assistive energy regeneration systems can be used. A hydraulic energy recovery system is modeled to be used as a regenerative system for supplementing energy storage for a pure electric articulated passenger bus. In this study a pump/motor machine is modeled to transform kinetic energy into hydraulic energy during braking, to move the hydraulic fluid from the low pressure reservoir to the hydraulic accumulator. The simulation of the proposed system was used to estimate battery savings. It was found that on average, approximately 39% of the battery charge can be saved when using a real bus driving cycle.

Advanced internal combustion engines, although generally more efficient than conventional combustion engines, often encounter limitations in multi-cylinder applications due to variations in the combustion process. This study leverages experimental data from an inline 6-cylinder heavy-duty dual fuel engine equipped with a fully-flexible variable intake valve actuation system to study cylinder-to-cylinder variations in power production. The engine is operated with late intake valve closure timings in a dual-fuel combustion mode featuring a port-injection and a direct-injection fueling system in order to improve fuel efficiency and engine performance. Experimental results show increased cylinder-to-cylinder variation in IMEP as IVC timing moves from 570°ATDC to 610°ATDC, indicating an increasingly uneven fuel distribution between cylinders.

This paper introduces design, control, and power management of a battery/ ultra-capacitor hybrid system, utilized for small electric vehicles (EV). The batteries are designed and controlled to work as the main energy storage source of the vehicle, supplying average power to the load; and the ultra-capacitors are used to meet the peak power demands during transients. Power management system determines the directions of power flow, according to load demand. Presented analyses validate the efficient power management methodology.

Safety control and protection strategy of high-voltage system of electric vehicles include analysis of circuit condition before connection to high voltage terminal, transient current prevention for capacitive load, real-time monitoring and analysis of high-voltage system during operation, disconnecting strategy of high voltage terminals, vehicle dynamic safety and cooperative management of electrical systems, etc. Monitoring and analysis of some critical parameters of high voltage system such as insulation, electrical harness and connector condition are the basis and difficulties in high-voltage safety and protection. This paper presents several mathematical models of monitoring critical parameters, and experiments were also done to evaluate the model. Disadvantages of the commonly used calculation method are discussed. Single point insulation defect model is introduced and diagnosis method of multiple points defect is also discussed.

The Illinois Institute of Technology (IIT) Interprofessional Projects (IPRO®) Program engages multidisciplinary teams of students in semester-long projects, with a total of thirty to thirty-five different projects offered every semester. This program greatly contributes to IIT's signature undergraduate education experience, with each interprofessional course delivering a team-oriented, project-based requirement within the undergraduate curriculum. Among its many benefits, each interprofessional course offers students the opportunity to integrate the education and research environment of the university to tackle real-world problems. In the process, students get the chance to develop and emerge from the experience with maturity, confidence, and valuable professional skills that are highly sought after in the workplace, simultaneously preparing them for the realities of today's global, highly-competitive environment [1].

This paper focuses on the effects of ultra-capacitors as a component of energy storage in hybrid electric vehicles (HEV). The main energy source in a hybrid vehicle is the battery. HEVs with battery sources are presently fairly effective; however, major drawbacks include the cost and size of such batteries. The purpose of this paper is to demonstrate that the addition of ultra-capacitors as a component of the energy storage system can reduce these drawbacks significantly by reducing the size of batteries required to drive the vehicle. To integrate ultra-capacitors into hybrid vehicles, the ADvanced VehIcle SimulatOR (ADVISOR) was used. The vehicle used to conduct this study was the 2004 Jeep Liberty sport utility vehicle (SUV). To simplify the analysis process, the conventional Jeep Liberty was modeled in ADVISOR to resemble the actual performance specifications of the SUV currently in the market.

Intensifying demands for higher fuel economy from one hand and environmental concerns from the other are driving advanced automotive power systems to be more electric. As a result, automotive electrical systems with higher capacity and more complexity are needed to cope with this expanding electrification trend. As different electrical applications and loads are being introduced in automobiles, multi-converter intensive power electronic systems are emerging as the next generation of the advanced automotive electrical systems. In fact, power electronic converters and electric motor drives are inevitable parts of more electric automotive power systems. When power electronic converters and electric motor drives are tightly regulated to improve system performance and efficiency, they present negative impedance characteristics of constant power loads to the entire automotive electrical system. This destabilizing effect may cause system instability.

Due to the low cost of the battery cells and excellent performance at ambient temperature, Lithium-ion (Li-ion) battery is a promising technology for propulsion applications. However, the performance of Li-ion batteries erodes drastically at extreme temperatures (above 65 °C or below 0 °C). Therefore, in order to maintain battery life and performance, it is crucial to keep the batteries within the temperature range where their operating characteristics are optimal. The need for expensive and complex thermal management systems has in fact kept the Li-ion technology from becoming the first choice for Hybrid Electric Vehicle (HEV) applications. In this paper, we propose a Phase Change Material (PCM) for the temperature control. Due to its high heat capacity, PCM absorbs the heat dissipated by the battery. As long as the heat emitted by the battery does not melt the PCM completely, the system is stable.

The increasing power demand in vehicles has resulted in a need for a higher onboard generation capacity. With the increasing generation requirement, the torque levels of the generator are found to closely converge with that of the starter motor. Hence, integrating the two machines and using a single machine for the two purposes would be technically viable and economically advantageous. This results in a more compact design solution as well. The Integrated Starter/Alternator (ISA) will be integrated directly to the crankshaft of the Internal Combustion Engine (ICE) and deliver 5 kW average and 12-15 kW peak power at 42V.

In land vehicles with high-power electrical loads, other than the low-voltage DC bus (14V, 28V, or 42V) for the low-power conventional loads, a high-voltage bus, e.g., 200V DC, is required for high-power loads such as hotel loads and electrically-assisted propulsion systems. In addition, some advanced electrical loads including luxury loads and AC power point require 120V, 60Hz AC voltage. These land vehicles include heavy duty, fire fighting, and military vehicles. There are two traditional approaches in obtaining a dual DC voltage bus system. The first one is to obtain the low-voltage DC from the alternator and boost it to the high-voltage DC. The second method is to obtain the high-voltage DC directly from the alternator and reduce it to the low-voltage. Both approaches require additional step-up or step-down power conversion stages, which inherently result in a reduced efficiency. In this paper, a new approach with a 28V/200V dual voltage alternator is considered.

Demands for higher fuel economy, performance, reliability, convenience, as well as reduced emissions push the automotive industry to seek electrification of ancillaries and engine augmentations. In cars of the future, throttle actuation, steering, anti-lock braking, rear-wheel steering, active suspension and ride-height adjustment, air-conditioning, and electrically heated catalyst will all benefit from the electrical power system. Therefore, a higher system voltage, such as the proposed 42V, is necessary to handle these new introduced loads. In this paper, an overview of the systems that will benefit from the 42V bus is presented. Effects of the new introduced electrical loads on the electrical power systems of conventional cars are described. Dynamic characteristics of each load for a typical drive cycle are defined. In addition, system level issues and vehicle performances such as fuel economy are addressed.

A library of macro modules has been written that represent elements common to powertrains of off-highway equipment with diesel powerplants and powershift transmissions. This library allows users to easily and quickly develop complex models of a wide range of vehicle and transmission configurations. These simulation models can be used to evaluate dynamic loadings on the powertrain components, evaluate shift quality, develop control systems and address other powertrain dynamic problems. The library makes use of EASY5 simulation language features to effectively handle such drivetrain nonlinearities as backlash, coulomb friction and hard stops.