scholarly journals Design of Genetic Programming Control Algorithm for Low-Temperature PEM Fuel Cell

2021 ◽  
Vol 8 ◽  
Author(s):  
Abdel Gafoor Haddad ◽  
Ahmed Al-Durra ◽  
Igor Boiko

An effective control system for the air supply in fuel cell systems (FCS) is required to prevent oxygen starvation and to maximize the net power. For this purpose, conventional feedback and adaptive controllers are designed using genetic programming (GP). To minimize the time required for the GP convergence, FCS models of different complexity are studied and a comparison between them is carried out. Guidelines on applying the GP approach based on data obtained from simulations are developed along with a specially designed cost function that promotes closed-loop linearization. The advantage of this design method lies in its applicability to complex nonlinear systems for which nonlinear control methods may not be applicable. Adaptation is added to the oxygen excess ratio (OER) regulation problem by training a neural network that provides the optimal OER reference based on the stack current and temperature. The performance of both the regulation and adaptive controllers is tested under noise in the compressor flow and the stack current measurements. The robustness of the GP controllers is observed through the frequency response analysis.

1972 ◽  
Vol 7 (1) ◽  
pp. 13-20
Author(s):  
D.D.P. Cane ◽  
G.J. Farguhar

Abstract A case of filamentous activated sludge bulking was investigated at an extended aeration plant treating wastes from a highway service centre. The purpose of the study was to find an effective control measure for the bulking and, if possible, to determine the cause of the bulking condition. Experiments were conducted to determine the effects upon bulking of: (a) a controlled copper dosage to the mixed liquor, (b) variations in the organic loading rate, and (c) maintenance of high and low dissolved oxygen concentrations in the mixed liquor. The microorganism responsible for the bulking condition was tentatively identified as Sphaerotilus natans. Extensive growths of these bacteria occurred in the sludge when the mixed liquor dissolved oxygen concentration dropped below 0.5 mg/1. Such dissolved oxygen levels had frequently occurred at this plant due to the use of timed aeration cycles and the use of insufficient air supply during peak loading periods. Variations in organic loading rates were found to have no adverse effect on sludge settleability. When bulking was slight, the condition could be improved by increasing the dissolved oxygen level to 1.5 mg/1, or more. The rate at which the filamentous growths could be eliminated from a highly filamentous sludge by increased aeration was very slow, but could be greatly increased by the simultaneous feeding of copper to the mixed liquor at a dosage rate of 1.0 mg/1, based on the raw sewage flows.


Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1140
Author(s):  
Xiao Tang ◽  
Chunsheng Wang ◽  
Yukun Hu ◽  
Zijian Liu ◽  
Feiliang Li

An effective oxygen excess ratio control strategy for a proton exchange membrane fuel cell (PEMFC) can avoid oxygen starvation and optimize system performance. In this paper, a fuzzy PID control strategy based on granular function (GFPID) was proposed. Meanwhile, a proton exchange membrane fuel cell dynamic model was established on the MATLAB/Simulink platform, including the stack model system and the auxiliary system. In order to avoid oxygen starvation due to the transient variation of load current and optimize the parasitic power of the auxiliary system and the stack voltage, the purpose of optimizing the overall operating condition of the system was finally achieved. Adaptive fuzzy PID (AFPID) control has the technical bottleneck limitation of fuzzy rules explosion. GFPID eliminates fuzzification and defuzzification to solve this phenomenon. The number of fuzzy rules does not affect the precision of GFPID control, which is only related to the fuzzy granular points in the fitted granular response function. The granular function replaces the conventional fuzzy controller to realize the online adjustment of PID parameters. Compared with the conventional PID and AFPID control, the feasibility and superiority of the algorithm based on particle function are verified.


Author(s):  
Talal Ous ◽  
Elvedin Mujic ◽  
Nikola Stosic

Water injection in twin-screw compressors was examined in order to develop effective humidification and cooling schemes for fuel cell stacks as well as cooling for compressors. The temperature and the relative humidity of the air at suction and exhaust of the compressor were monitored under constant pressure and water injection rate and at variable compressor operating speeds. The experimental results showed that the relative humidity of the outlet air was increased by the water injection. The injection tends to have more effect on humidity at low operating speeds/mass flow rates. Further humidification can be achieved at higher speeds as a higher evaporation rate becomes available. It was also found that the rate of power produced by the fuel cell stack was higher than the rate used to run the compressor for the same amount of air supplied. The efficiency of the balance of plant was, therefore, higher when more air is delivered to the stack. However, this increase in the air supply needs additional subsystems for further humidification/cooling of the balance-of-plant system.


1997 ◽  
Vol 5 (2) ◽  
pp. 181-211 ◽  
Author(s):  
Elena Zannoni ◽  
Robert G. Reynolds

Traditional software engineering dictates the use of modular and structured programming and top-down stepwise refinement techniques that reduce the amount of variability arising in the development process by establishing standard procedures to be followed while writing software. This focusing leads to reduced variability in the resulting products, due to the use of standardized constructs. Genetic programming (GP) performs heuristic search in the space of programs. Programs produced through the GP paradigm emerge as the result of simulated evolution and are built through a bottom-up process, incrementally augmenting their functionality until a satisfactory level of performance is reached. Can we automatically extract knowledge from the GP programming process that can be useful to focus the search and reduce product variability, thus leading to a more effective use of the available resources? An answer to this question is investigated with the aid of cultural algorithms. A new system, cultural algorithms with genetic programming (CAGP), is presented. The system has two levels. The first is the pool of genetic programs (population level), and the second is a knowledge repository (belief set) that is built during the GP run and is used to guide the search process. The microevolution within the population brings about potentially meaningful characteristics of the programs for the achievement of the given task, such as properties exhibited by the best performers in the population. CAGP extracts these features and represents them as the set of the current beliefs. Beliefs correspond to constraints that all the genetic operators and programs must follow. Interaction between the two levels occurs in one direction through the extraction process and, in the other, through the modulation of an individual's program parameters according to which, and how many, of the constraints it follows. CAGP is applied to solve an instance of the symbolic regression problem, in which a function of one variable needs to be discovered. The results of the experiments show an overall improvement on the average performance of CAGP over GP alone and a significant reduction of the complexity of the produced solution. Moreover, the execution time required by CAGP is comparable with the time required by GP alone.


2010 ◽  
Vol 20 (3) ◽  
pp. 325-336 ◽  
Author(s):  
Winston Garcia-Gabin ◽  
Fernando Dorado ◽  
Carlos Bordons

Sexual Health ◽  
2014 ◽  
Vol 11 (3) ◽  
pp. 217 ◽  
Author(s):  
David J. Templeton ◽  
Phillip Read ◽  
Rajesh Varma ◽  
Christopher Bourne

Men who have sex with men (MSM) in Australia and overseas are disproportionately affected by sexually transmissible infections (STIs), including HIV. Many STIs are asymptomatic, so regular testing and management of asymptomatic MSM remains an important component of effective control. We reviewed articles from January 2009–May 2013 to inform the 2014 update of the 2010 Australian testing guidelines for asymptomatic MSM. Key changes include: a recommendation for pharyngeal chlamydia (Chlamydia trachomatis) testing, use of nucleic acid amplification tests alone for gonorrhoea (Neisseria gonorrhoeae) testing (without gonococcal culture), more frequent (up to four times a year) gonorrhoea and chlamydia testing in sexually active HIV-positive MSM, time required since last void for chlamydia first-void urine collection specified at 20 min, urethral meatal swab as an alternative to first-void urine for urethral chlamydia testing, and the use of electronic reminders to increase STI and HIV retesting rates among MSM.


Química Nova ◽  
2021 ◽  
Author(s):  
Shi Lei ◽  
Zheng Minggang

In this paper, the influence of the optimization for flow field size on the proton exchange membrane fuel cell (PEMFC) performance under the inadequate air supply of cathode was studied based on the three-dimensional, steady-state, and constant temperature PEMFC monomer model. Additionally, the effect of the optimization for hybrid factors, including length, width, depth and width-depth, on the PEMFC performance was also investigated. The results showed that the optimization of the flow field size can improve the performance of the PEMFC and ensure that it is close to the level under the normal gas supply.


2021 ◽  
Vol 49 (3) ◽  
pp. 549-562
Author(s):  
Masih Hanifi ◽  
Hicham Chibane ◽  
Rémy Houssin ◽  
Denis Cavallucci

TRIZ method has long proven its value without appearing to the industrial world as inevitable. Design researchers have therefore addressed the limitations of the TRIZ method and have overcome them with more systematic approaches. Among these, the Inventive Design Method (IDM) has been the subject of several articles and put into practice in the industry. It is considered an improvement over TRIZ but still suffers from some drawbacks in terms of the time-consuming nature of its implementation. We focused on the IDM process by trying to both identify its areas of inefficiencies while attempting to preserve the quality of its deliverables. Our approach consists of applying the precepts of Lean to IDM. The result is the Inverse Problem Graph (IPG) method, inspired by IDM, but offering significant progress in reducing the time required to mobilize experts while preserving its inventive outcomes. This article outlines our approach for the construction of this new method.


2008 ◽  
Vol 1 (1) ◽  
pp. 258-266 ◽  
Author(s):  
Jochen Sang ◽  
Massimo Venturi ◽  
Ralf Bocksch
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