Automotive Science and Engineering

Reliability Assessment and Congestion Management of Power System with Electric Vehicles and Uncertain Renewable Resources

alireza sobbouhi

The high penetration of renewable energy sources (RES) makes the power system unreliable due to its uncertain nature. In this paper, the quantifying impact of electric vehicles (EV) charging and discharging on power system reliability and relieving the congestion is analyzed. The proposed reliability assessment is formulated by considering generation and demand interruption costs for N-1 contingency criteria. The proposed algorithm manages the optimal scheduling of EV to mitigate the uncertainties associated with RES and relieving the congestion. The impact of EV charging and discharging on expected energy not supplied (EENS) and expected interruption cost (ECOST) for generating companies (GENCOs), transmission companies (TRANSCOs), customers, and entire power system are calculated. The charging station of EV is selected by the trade-o_ between investment cost of EV and percentage change in EENS and ECOST value for the entire power system, GENCOs, TRANSCOs, and customers. The effectiveness of the proposed approach is tested on the modified IEEE RTS 24 bus system. The impact of EV charging stations on system reliability has been evaluated by quantifying the EENS and the ECOST across all available EV capacities. The results clearly demonstrate the improvement of system reliability and minimize the objective function consisting of generator re-dispatch and load curtailment considering N-1 contingency in the face of uncertainties of wind and solar generation sources by considering EV. The results show that EV can improve the reliability by about 40%. The problem is modeled in GAMS environment and solved using CONOPT as a nonlinear programming (NLP) solver.

Differential Transformation Method for Vibration Analysis of Porous Functionally Graded Folded Plates

Mostafa Talebitooti

This paper presents a novel investigation into the free vibration of porous folded plates using the differential transformation method (DTM). The porosity is functionally graded (FG) along the thickness of the plate, resulting in material properties that vary with the z-coordinate. The motion equations for each plate segment are derived based on classical plate theory (CPT), with simply-supported boundary conditions applied at the front edges, allowing the transformation of partial differential equations into ordinary differential equations. The differential transformation method is then employed to discretize the motion equations in the x-direction. By applying boundary conditions at the remaining edges and ensuring continuity at the joints, the eigenvalue problem is formulated, leading to the calculation of natural frequencies and mode shapes of the folded plate. The mathematical model is validated through comparisons with finite element method (FEM) results and existing literature. Results indicate that Type C porosity distributions exhibit the highest stiffness and resonant frequency compared to other porosity types. While frequency behavior is consistent across mode numbers regardless of porosity distribution and plate length, the impact of the porosity parameter on the frequency of Type C plates is demonstrably less significant than on other porosity types.

New approaches in driveline shunt and shuffle control by a dry clutch

Milad Badri Kouhi

A new idea is applied for damping of driveline oscillation (shunt and shuffle) created because of sudden changes in transmitting engine torque. In this case, by an actuator the dry clutch slides due to decreasing in clutch clamp force. By regulating the clutch force, it prevents the excessive torque from entering the driveline, which causes vibrations. This strategy eliminates the oscillations. Hence, the driveline dynamics which consists of the clutch model, driveline elements, backlash, and tire slip is modeled comprehensively in the MATLAB software and validated. When the vibrations are sensed by sensors, the electronic control unit directs the clutch actuator by changing the normal clutch force so the dry clutch slides and dampens the vibrations. For this idea, three controlling approaches are suggested: a rule-based controller, a pulse controller, and a linear predictive controller. Essential tests for examining driveline control performance are chosen and then the driveline performance is assayed for it. Also, one of the priorities in selecting a clutch control strategy is to increase the clutch lifetime. From the results, driveline vibrations including shunt and the shuffle can be reduced well. In addition, this idea doesn’t have the harms of the other solutions such as spark advance engine control that pollutes the air and electronic throttle control which lessens the vehicle performance. Moreover, the usage of this system is simple, especially in vehicles that have automatic manual transmission.

A Holistic Approach to Reactivity-Controlled Compression Ignition Engine Performance: 4E Analysis (Evaporation, Energy, Emissions, Exergy) and Multidimensional Efficiency Metrics under Varying Engine Speed

Mehran Nazemian

This study investigates the performance of Reactivity-Controlled Compression Ignition (RCCI) engines under varying engine speeds using a 4E approach (Evaporation, Energy, Emissions, Exergy) and introduces innovative multidimensional efficiency indices. A 1.9-liter TDI Volkswagen engine was modeled in CONVERGE CFD software to analyze spray dynamics, combustion processes, and emissions across different engine speeds. New indices, including Evaporation-Energy Performance Index (EvEPI), Emission-Energy Synergy Index (EmESI), and Exergy-Emission Balance Index (ExEmBI), were developed to evaluate engine performance comprehensively. Results reveal that optimal performance occurs within 1600–2200 RPM, where fuel evaporation, combustion efficiency, and exergy utilization are maximized while emissions are minimized. For instance, at 3100 RPM, EvEPI increases sharply to 9857.17 mg/ms, reflecting enhanced evaporation but also highlighting risks of non-uniform fuel-air mixing at high speeds. Conversely, EmESI for HC rises from 33.04 gr/kW.h at 1000 RPM to 284.90 gr/kW.h at 3100 RPM, indicating increased unburned hydrocarbons due to incomplete combustion. NOx emissions decrease from 11.51 gr/kW.h at 1600 RPM to 2.28 gr/kW.h at 3100 RPM, aligning with reduced combustion temperatures. Higher speeds lead to elevated HC and CO emissions due to shorter mixing times, while lower speeds increase NOx due to prolonged combustion durations. Exergy analysis shows total and second-law efficiencies peak at lower speeds, emphasizing the importance of optimizing operational parameters. These findings provide valuable insights for designing efficient, low-emission RCCI engines.

A Novel Parallel Control Architecture for Integrated Electro-Hydraulic Brake to Simultaneously Enhance Braking Performance and Vehicle Stability

Nayereh Raesian

Emergency braking during cornering is one of the main challenges in vehicle dynamics. This paper proposes a novel parallel control architecture for Electro-Hydraulic Braking (EHB) systems that dynamically balances the priorities of Emergency Braking (EB) and Electronic Stability Control (ESC) using a fuzzy-GA optimizer. . The proposed approach achieves significant improvements in yaw stability without compromising deceleration performance. The proposed control structure consists of two parallel branches that adjust the required pressure for each wheel and uses two inputs: the steering angle and the position of the driver's foot on the brake pedal. The control system is structured in such a way that it simultaneously calculates the vehicle deviation value using the sliding mode controller and then determines the appropriate pressure to compensate for this deviation, while at the same time estimating the appropriate brake pressure based on the brake pedal input. To effectively apply these inputs to the vehicle braking system this paper introduces an innovative approach that uses a fuzzy controller optimized through a genetic algorithm.

Analytical Model for Estimating the Motion of the Liquid Metal Drop-let in Electromagnetic Micropump

Mohsen Karmozdi

The liquid metal droplets in the mercury magnetic reciprocating micropump are actuated by Lorentz force and reciprocated inside some sub-channels. The droplets in sub-channel act as pistons to pump the working fluid. The initial step in establishing the performance of the mercury magnetic reciprocating micropumps is to study the motion of droplet inside the channel. The extraction of the analytic equation governing the droplet motion inside the channel is complicated due presence of electromagnetic fields and three dimensional effects of the flow. Further, the existence of a pumped fluid in contact with the droplet and the adhesion force due to small dimensions are considered as the other reasons. In this study, the forces operating on the droplet were figured out by the Lagrangian approach and lumped mass assumption for the droplet. Accordingly, forces less than 5% of the actuation force were eliminated from the motion equation of droplet employing dimensional analysis. The simplified equation was presented as an ordinary differential equation and solved numerically. In addition to the analytic solution, the issue was experimentally investigated for a case study. The analytic and empirical results accord well with one another. The method pointed out in this study can be applied to predict the droplet motion in various microsystems.