Mohamed Benbouzid

Optimal design of a PV/fuel cell hybrid power system for the city of Brest in France

This paper deals with the optimal design of a stand-alone hybrid photovoltaic and fuel cell power system without battery storage to supply the electric load demand of the city of Brest, Western Brittany in France. The proposed optimal design study is focused on economical performances and is mainly based on the loss of the power supply probability concept. The hybrid power system optimal design is based on a simulation model developed using HOMER. In this context, a practical load demand profile of Brest city is used with real weather data.

A smart algorithm for the diagnosis of short-circuit faults in a photovoltaic generator

This paper deals with a smart algorithm allowing short-circuit faults detection and diagnosis of PV generators. The proposed algorithm is based on the hybridization of a support vector machines (SVM) technique optimized by a k-NN tool for the classification of observations on the classifier itself or located in its margin. To test the proposed algorithm performance, a PV generator database containing observations distributed over classes is used for simulation purposes.

A regression algorithm for the smart prognosis of a reversed polarity fault in a photovoltaic generator

This paper deals with a smart algorithm allowing reversed polarity fault diagnosis and prognosis in PV generators. The proposed prognosis (prediction) approach is based on the hybridization of a support vector regression (SVR) technique optimized by a k-NN regression tool (K-NNR) for undetermined outputs. To test the proposed algorithm performance, a PV generator database containing sample data is used for simulation purposes.

A systemic design methodology of PM generators for fixed-pitch marine current turbines

This paper deals with the systemic design of permanent magnet (PM) generator associated with fixed-pitch turbine for tidal energy generation. The main problem with marine current turbines systems are the maintenance requirements of the drive-train. It is known that the blade pitch system increases the complexity, cost, and the maintenance requirements of the drive-train. In offshore energy generation, the maintenance should be minimized as much as possible. For that purpose direct-drive permanent-magnet machines associated with fixed-pitch marine turbines can be an attractive solution. The main challenge with fixed-pitch blades is to ensure the power limitation of the turbine at high speed without using variable pitch system. As solution, we propose a systemic design approach of the generator that takes into account the power limitation requirement. In addition, this methodology takes into account the tidal site energy potential, the turbine characteristic, the control strategy, the generator specifications and the power converter constraints. The obtained results show the feasibility of our approach to satisfy the control strategy requirements.

Application of flow battery in marine current turbine system for daily power management

Predictable tidal current resources make marine current turbine (MCT) generation system highly attractive as an electricity supply source for coastal areas and remote islands. However, the tidal speed varies greatly due to the flood and ebb tides during one day period. This results large mismatch between MCT produced power and grid-side (or load-side) demanded power. This paper focuses on a grid-connected MCT system and proposes using vanadium redox flow battery (VRB) energy storage system to manage the combined output power and to follow grid-side demand on a daily basis. The VRB model and parameter calculation process are detailed in this paper. The diesel generator (DG) system is considered as a backup power supply source in case of low battery state of charge (SoC) caused by losses during long-time battery operation. Simulations are carried-out on a grid-connected MCT system with VRB ESS to follow a given power demand profile during one day period. The results valid the proposed VRB sizing and control strategy. The DG system is demonstrated as a feasible solution to avoid VRB reaching its low SoC limitation and to guarantee the expected power injection to the local grid.

Performance analysis of an EEMD-based Hilbert Huang transform as a bearing failure detector in wind turbines

Sustainability and viability of wind farms are highly dependent on the reduction of the operational and maintenance costs. The most efficient way of reducing these costs would be to continuously monitor the condition of these systems. This allows for early detection of the degeneration of the generator health, facilitating a proactive response, minimizing downtime, and maximizing productivity. This paper deals then with the assessment of a demodulation technique for bearing failure detection through wind turbines generator stator current. The proposed technique is based on a modified version of the Hilbert Huang transform. In this version, the use of the EEMD algorithm allows overcoming the well-known mixed mode.

A virtual synchronous generator based inverter control method for distributed generation systems

The sustainable energy based generation systems, such as photovoltaic and wind turbine generation systems, normally adopt inverters to connect to the grid. These power electronics interfaces possess characteristics of small inertia and small output impedance, which create difficulties to stabilize the voltage and frequency of a distributed micro power source. To deal with this problem, this paper is focus on the research of a virtual synchronous generator based control method by introducing virtual inertia into the control loop and emulating the control scheme of a traditional synchronous generator. After discussing the design process of the virtual speed and excitation regulators, system stability and parameter sensibility have been analyzed. At last, some simulations have been carried out and the effectiveness of proposed method is demonstrated by simulation results comparison and analysis.

An integral sliding mode controller with super-twisting algorithm for direct power control of wind generator based on a doubly fed induction generator

In order to reduce the chattering phenomena in the conventional sliding mode control, which appears mostly in the rotor currents, the integral sliding mode controller using the super-twisting algorithm is proposed. In this controller, the sliding surfaces are chosen so that they will be compatible with the errors in the stator active and reactive powers. The simulation results obtained when using a three blades wind turbine based a doubly fed induction generator; show the robustness of the proposed control model. The minimization of the chattering such as in the direct and the quadrature component of the rotor currents, which represents in the reducing of total harmonics distortion of the rotor currents and equal, to 3.82 and 3.54, resulting from the application of the integral sliding mode controller with sign function and with super-twisting algorithm respectively.

Modeling and Simulation of a PMSG-based Marine Current Turbine System under Faulty Rectifier Conditions

Abstract This paper deals with the modeling and simulation of a permanent magnet synchronous generator (PMSG)-based marine current turbine (MCT) under faulty rectifier conditions. The modeling of the generator is established in the synchronous rotating d-q reference frame. The control of the speed, the d-axis current, and the q-axis current are achieved using proportional integral (PI) correctors. The faulty mode deals with the study of single and multiple open-switch damages appearing in the pulse width modulation (PWM) power rectifier. Simulations are carried out to highlight the proposed PMSG-based MCT performance in both cases using MATLAB/Simulink environment.

Imbalance fault detection of marine current turbine under condition of wave and turbulence

Marine current turbine (MCT) have been widely used nowadays, it is important to monitor their health state. Unnecessary marine biological growth or marine pollutants attached to the moving parts will affect the operation of the system by introducing imbalance. The imbalance, regarded as faults, would change the performance of turbine and lead to progressively increasing damages. In this paper, a marine current turbine prototype with permanent magnet synchronous generator (PMSG) has been studied. An innovative imbalance fault detection method is proposed for marine current turbines under the condition of wave and turbulence. In the proposed method, the average frequency of current is calculated through synchronous sampling. Meanwhile, current fluctuation influence is reduced during one revolution. The empirical mode decomposition (EMD) and spectrum analysis are used to achieve fault characteristics. Theoretical analysis, simulation and experimental results under different conditions validate the proposed method. Moreover the proposed method could be used for long-term marine current turbine monitoring in respect to its simplicity and low time cost.