This paper presents a comparative study between two strategies for the direct torque control (DTC) of the permanent magnet synchronous generator (PMSG) based on wind energy conversion system (WECS). The first method is a conventional direct torque control DTC and it is based on hysteresis controllers where the torque and the flux are regulated by these controllers. The second one is direct torque control by space vector modulation strategy (DTC-SVM) where the torque and flux are regulated by PI controllers. The simulation results are implemented by using MATLAB/SIMULINK. The main feature of the proposed (DTC-SVM) strategy is the reduction of torque and flux ripples. The proposed approach can be considered as an alternative solution to the control of PMSG.

This investigation examines mathematical modelling and experimental validation of two types of solar cookers: a box type with tilted intercept area equipped with one external reflector, and a parabolic cooker with a new configuration. Experiments were carried out with the cookers filled with two kilograms of water from 08:00 to 15:00 solar time. During the experiments, temperature gain in the box-type solar cooker was recorded at about 69.8 °C and in the parabolic-type solar cooker at 73.6 °C at the stagnation point. Direct normal irradiation in three distinct study areas was observed and found that it varied from 7.6 to 10 kWh m⁻². Cooking pot placed in parabolic cooker was varied between 130 and 132 °C. Centre and south-east regions of study areas where global irradiation varied from 8 to 8.4 kWh m⁻² were found suitable for box-type solar cooker and cooking pot temperature were found in the range of 100 °C to 105 °C. Mathematical modelling was programmed in MATLAB. The theoretical results were consistent with experiential data for both types of solar cookers. The effectiveness of the two cooker types can be deduced from the maps. It is found the use of the cookers in Northern and Southern regions of the country was not identical. Their suitability for cooking depends on the amount of solar radiations received.

The magnetohydrodynamics (MHD) is an important interdisciplinary field. It is the interaction between an electromagnetic field and an electrically conducting fluid. Electromagnetic pumps are widely used for the transportation of the fluids in a variety of technological processes. The advantage of these devices is that permits the pumping of liquids without moving parts. The design of the pump is considered as an optimization problem where the objective function is the minimum of the MHD pump mass with both geometrical and electromagnetic contraints type. The obtained optimization results using the finite volume method with Matlab software show the performances of the used stochastic simulated annealing method.

This paper designs an indirect power control method for brushless doubly fed induction generator (BDFIG), in which the stator is attached to grid with back-to-back space vector modulation (SVM) converter that converts the generated wind power. Our control method is a sliding mode control based on the theory of variable structure control. Specifically, the active and reactive powers, which are exchanged between the stator of the BDFIG and the grid in a linear and decoupled manner, are subjected to decoupled, vector control. In addition, a proportional integral (PI) controller was implemented to keep the DC-voltage constant for the back-to-back SVM converter. The efficiency of our control strategy was validated through simulation. The research greatly promotes the control of renewable energy generators.

This paper deals with the robust power control of a grid-connected brushless doubly-fed induction generator (BDFIG) driven by the variable speed wind turbine. With the using of a super twisting algorithm which is a high-order sliding mode controller (HOSMC). This approach guarantees both the dynamic performance and the same robustness as traditional first order (SMC) algorithm and reduces the chattering phenomenon, which is the biggest disadvantage in the implementation of this technique. The developed algorithm relies on the decoupling control by implementing the strategy of oriented grid flux vector control. In order to enhance the desired performances, an attempt is made by controlling the generated stator active and reactive powers in a linear and decoupled manner to ensure the global asymptotical stability, HOSMC approach is implemented. Therefore, an optimal operation of the BDFIG in sub-synchronous operation is used in addition to the stator power flows where the stator power factor is kept in a unity. The suggested method is examined with the Matlab/Simulink software. The performances and the feasibility of the designed control are illustrated by simulation results.

Purpose The purpose of this paper is to validate a fuzzy risk graph model through a case study results carried out on a safety instrumented system (SIS). Design/methodology/approach The proposed model is based on an inference fuzzy system and deals with uncertainty data used as inputs of the conventional risk graph method. The coherence and redundancy of the developed fuzzy rules base are first verified in the case study. A new fuzzy model is suggested for a multi-criteria characterization of the avoidance possibility parameter. The fuzzy safety integrity level (SIL) is determined for two potential accident scenarios. Findings The applicability of the proposed fuzzy model on SIS shows the importance and pertinence of the proposed fuzzy model as decision-making tools in preventing industrial hazards while taking into consideration uncertain aspects of the data used on the conventional risk graph method. The obtained results show that the use of continuous fuzzy scales solves the problem of interpreting results and provides a more flexible structure to combine risk graph parameters. Therefore, a decision is taken on the basis of precise integrity level values and protective actions in the real world are suggested. Originality/value Fuzzy logic-based safety integrity assessment allows assessment of the SIL in a more realistic way by using the notion of the linguistic variable for representing information that is qualitative and imprecise and, therefore, ensures better decision making on risk prevention.

An increasing interest and efforts are being made at all levels by academics and practitioners to protect the workers and encourage the development of strategies and approaches to reduce the number of accidents at the workplace, improve the safety performance of the industrial companies and preserve the environmental health. In spite of the continuous efforts of the Algerian companies to improve their health and safety performance, high number of accidents and ill-health problems among the Algerian companies are still being recorded. In terms of definition, the Environmental Health refers to human’s health aspects including quality of life. These aspects are defined by the physical, biological, social and psychosocial factors of the environment. It includes also the theory and practice of assessing, correcting, controlling and preventing these factors in an environment which may potentially affect human’s health.This paper comes to explore the contribution of the alignment of the cluster cultural aspects (CA), health and Safety strategy (H&SS) and people (P) as a way to improve the environmental health, particularly the Musculoskeletal disorders (MSDs) that present one of the prominent and significant health problems at work.

Faced with different representation models of a work situation whose centers of interest vary from one model to another, guides have been developed to try and analyze occupational risks in their entirety. However, the development of these guides poses a double problem: the completeness of this analysis and the order attributed to the analyzed occupational risks. This article aims to solve this problem through a systemic approach that allows to develop a hierarchical model of occupational risks invariants. Its exploitation allows to carry out an exhaustive analysis of occupational risks and consequently the elaboration of a long-term strategy of prevention.

Purpose The purpose of this paper is to deal with the allocation requirements of the dependability of the multiphase systems. Design/methodology/approach It consists of a proposal for a combined methodology based on the simultaneous use of decomposition systems and reliability allocation method. Findings In the developed methodology, the authors use the principles of risk assessment and propose a new formulation of weight allowance with reference to the structural-functional dependence. Practical implications The suggested methodology provides invaluable help to implementation process analysis. Originality/value The adopted allocation approach is based on the use of a three-dimensional model: temporal, structural and functional decomposition of systems.

Purpose The risk control is an unavoidable step in the risk management process. It is materialized by concrete actions of risks reduction in order to decrease their likelihood and/or their severity and also to preserve the environment. The paper aims to discuss this issue. Design/methodology/approach The main goal of the proposed methodology is to define the safety barriers (SB) that can be realized and their contribution to reduce major accidents scenarios that may occur in high-risk establishments. Findings In the proposed methodology, the authors present a combination of methods to prove the effectiveness of SB in an industrial installation. Practical implications The proposed methodology is a valuable help to industrialists to secure their industrial activities and preserve the environment at the same time. Originality/value The retained methods are often used separately for audit purposes or risk assessments of high-risk industrial facilities. In this paper, three methods have been selected and articulated in an approach for a better evaluation of risk control level.

The decision process is considered as the key element for the smooth behavior of systems. For non-complex or linear systems, this process usually follows clear rules or requirements, so that the decision will be easy to make without any difficulty. In the case of complex (non-linear) systems, the decision-making process is repeatedly challenged problems because of the interactions of several factors at the same time and because of the hazards characterizing these factors. This situation will worsen further if the system goes out of its normal operating range to fall into uncertainty. In this paper, we will try to make our contribution, to arrive at simplifying the decision-making process, while playing on human factors (ability, anticipation, risk-taking, etc.). As this process can be improved by the development of intelligent decision support tools.

Malaysian construction industry is considered as substantial power for the economy of the country. The value of construction work is increasing year per year. Malaysia’s economy experienced a commendable growth the recent years; basically, the construction industry is statistically significant with economic development and has strong linkages with other industry sectors. However, the Malaysian construction industry is facing many challenges especially the fatal accidents. These last came first on top of the construction sector compared all other industries. This article describes the importance of the construction sector for Malaysia’s economy and its efficient contribution across all states of Malaysia. Furthermore, detailed statistics and analysis were carried out to describe the severity of fatal accidents occurred in construction industry of Malaysia. Besides, recommendations were listed in order to better manage the construction industry without involving in fatal accidents. By taking into account the significant influence of the construction industry on Malaysian economy, full attention should be given to the construction field by the Malaysian government and improve further the construction management in general and the construction safety in particular.