scholarly journals A Simple and Safe Strategy for Improving the Fuel Economy of a Fuel Cell Vehicle

Mathematics ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 604
Author(s):  
Nicu Bizon ◽  
Phatiphat Thounthong

A new real-time strategy is proposed in this article to optimize the hydrogen utilization of a fuel cell vehicle, by switching the control references of fueling regulators, based on load-following. The advantages of this strategy are discussed and compared, with advanced strategies that also use the aforementioned load-following mode regulator of fueling controllers, but in the entire loading range, respectively, with a benchmark strategy utilizing the static feed-forward control of fueling controllers. Additionally, the advantages of energy-storage function in a charge-sustained mode, such as a longer service life and reduced size due to the implementation of the proposed switching strategy, are presented for the dynamic profiles across the entire load range. The optimization function was designed to improve the fuel economy by adding to the total power of the fuel utilization efficiency (in a weighted way). The proposed optimization loop will seek the reference value to control the fueling regulator in real-time, which is not regulated by a load-following approach. The best switching threshold between the high and low loading scales were obtained using a sensitivity analysis carried out for both fixed and dynamic loads. The results obtained were promising—(1) the fuel economy was two-times higher than the advanced strategies mentioned above; and (2) the total fuel consumption was 13% lower than the static feed-forward strategy. This study opens new research directions for fuel cell vehicles, such as for obtaining the best fuel economy or estimating fuel consumption up to the first refueling station on the planned road.

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3537 ◽  
Author(s):  
Nicu Bizon ◽  
Mihai Oproescu

Besides three different real-time optimization strategies analyzed for the Renewable/ Fuel Cell Hybrid Power Systems (REW/FC-HPS) based on load-following (LFW) control, a short but critical assessment of the Real-Time Optimization (RTO) strategies is presented in this paper. The advantage of power flow balance on the DC bus through the FC net power generated using the LFW control instead of using the batteries’ stack is highlighted in this study. As LFW control consequence, the battery operates in charge-sustained mode and many advantages can be exploited in practice such as: reducing the size of the battery and maintenance cost, canceling the monitoring condition of the battery state-of-charge etc. The optimization of three FC-HPSs topologies based on appropriate RTO strategy is performed here using indicators such as fuel economy, fuel consumption efficiency, and FC electrical efficiency. The challenging task to optimize operation of the FC-HPS under unknown profile of the load demand is approached using an optimization function based on linear mix of the FC net power and the fuel consumption through the weighting coefficients knet and kfuel. If optimum values are chosen, then a RTO switching strategy can improve even further the fuel economy over the entire range of load.


Author(s):  
Kai Wu ◽  
Ming Kuang ◽  
Milos Milacic ◽  
Xiaowu Zhang ◽  
Jing Sun

Dynamic characteristics of a proton exchange membrane fuel cell (PEMFC) system can impact fuel economy and load following performance of a fuel cell vehicle, especially if those dynamics are ignored in designing top-level energy management strategy. To quantify the effects of fuel cell system (FCS) dynamics on optimal energy management, dynamic programming (DP) is adopted in this study to derive optimal power split strategies at two levels: Level 1, where the FCS dynamics are ignored, and Level 2, where the FCS dynamics are incorporated. Analysis is performed to quantify the differences of these two resulting strategies to understand the effects of FCS dynamics. While Level 1 DP provides significant computational advantages, the resulting strategy leads to load following errors that need to be mitigated using battery or FCS itself. Our analysis shows that up to 5% fuel economy penalty on New York city cycle (NYCC) and 3% on supplemental federal test procedure (US06) can be resulted by ignoring FCS dynamics, when the dominant dynamics of the FCS has settling time as slow as 8 seconds.


Fuel Cells ◽  
2018 ◽  
Vol 18 (6) ◽  
pp. 809-823 ◽  
Author(s):  
N. Bizon ◽  
G. Iana ◽  
E. Kurt ◽  
P. Thounthong ◽  
M. Oproescu ◽  
...  

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3148 ◽  
Author(s):  
Daniel Ritzberger ◽  
Christoph Hametner ◽  
Stefan Jakubek

Fuel cell systems are regarded as a promising candidate in replacing the internal combustion engine as a renewable and emission free alternative in automotive applications. However, the operation of a fuel cell stack fulfilling transient power-demands poses significant challenges. Efficiency is to be maximized while adhering to critical constraints, avoiding adverse operational conditions (fuel starvation, membrane flooding or drying, etc.) and mitigating degradation as to increase the life-time of the stack. Owing to this complexity, advanced model-based diagnostic and control methods are increasingly investigated. In this work, a real time stack model is presented and its experimental parameterization is discussed. Furthermore, the stack model is integrated in a system simulation, where the compressor dynamics, the feedback controls for the hydrogen injection and back-pressure valve actuation, and the purging strategy are considered. The resulting system simulation, driven by the set-point values of the operating strategy is evaluated and validated on experimental data obtained from a fuel cell vehicle during on-road operation. It will be shown how the internal states of the fuel cell simulation evolve during the transient operation of the fuel cell vehicle. The measurement data, for which this analysis is conducted, stem from a fuel cell research and demonstrator vehicle, developed by a consortium of several academic and industrial partners under the lead of AVL List GmbH.


Author(s):  
Panini Kolavennu ◽  
Susanta K. Das ◽  
K. Joel Berry

A robust control strategy which ensures optimum performance is crucial to proton exchange membrane (PEM) fuel cell development. In a PEM fuel cell stack, the primary control variables are the reactant’s stochiometric ratio, membrane’s relative humidity and operating pressure of the anode and cathode. In this study, a 5 kW (25-cell) PEM fuel cell stack is experimentally evaluated under various operating conditions. Using the extensive experimental data of voltage-current characteristics, a feed forward control strategy based on a 3D surface map of cathode pressure, current density and membrane humidity at different operating voltages is developed. The effectiveness of the feed forward control strategy is tested on the Green-light testing facility. To reduce the dependence on predetermined system parameters, real-time optimization based on extremum seeking algorithm is proposed to control the air flow rate into the cathode of the PEM fuel cell stack. The quantitative results obtained from the experiments show good potential towards achieving effective control of PEM fuel cell stack.


2020 ◽  
Vol 53 (7-8) ◽  
pp. 1493-1503
Author(s):  
Yang Li ◽  
Jili Tao ◽  
Liang Xie ◽  
Ridong Zhang ◽  
Longhua Ma ◽  
...  

Power allocation plays an important and challenging role in fuel cell and supercapacitor hybrid electric vehicle because it influences the fuel economy significantly. We present a novel Q-learning strategy with deterministic rule for real-time hybrid electric vehicle energy management between the fuel cell and the supercapacitor. The Q-learning controller (agent) observes the state of charge of the supercapacitor, provides the energy split coefficient satisfying the power demand, and obtains the corresponding rewards of these actions. By processing the accumulated experience, the agent learns an optimal energy control policy by iterative learning and maintains the best Q-table with minimal fuel consumption. To enhance the adaptability to different driving cycles, the deterministic rule is utilized as a complement to the control policy so that the hybrid electric vehicle can achieve better real-time power allocation. Simulation experiments have been carried out using MATLAB and Advanced Vehicle Simulator, and the results prove that the proposed method minimizes the fuel consumption while ensuring less and current fluctuations of the fuel cell.


Author(s):  
Ajay Kumar ◽  
Sachin Mishra ◽  
Brajesh Tripathi ◽  
Pradeep Kumar ◽  
Ish Hunar Sharma

This paper presents design, analysis and development of a highly aerodynamic and a near zero emission single seater three wheeler unfrozen hawk prototype vehicle that is powered by hydrogen fuel cell. The vehicle is designed with a tadpole configuration and gullwing doors to achieve low drag and a streamlined half body. The pressure and velocity distribution with an optimal value of drag coefficient are established using computational fluid dynamic analysis. The hydrogen consumption and heat generated in the fuel cell and brushless direct current motor are analyzed for various cases. The study concluded to show a reduction in power and fuel consumption of designed prototype vehicle to give better fuel economy and overall performance.


Sign in / Sign up

Export Citation Format

Share Document