An energy management method for a hybrid power system based on optimal control is developed in this paper. The hybrid system is a set of a photovoltaic panel as the main energy source, a fuel cell and a storage system based on a supercapacitor power bank. The fuel cell has a weak point from the point of view of slow dynamics since the power slope is limited to avoid problems of lack of fuel cell. The very fast power response of a supercapacitor complements the slow power output of the fuel cell to produce the necessary compatibility and performance characteristics in a DC load. Each source is connected to a DC/DC converter. Optimal control has been processed to ensure power sharing between sources and load. In this article, the detailed description of the hybrid system, the modeling of the DC/DC converters and the optimal control are provided. Finally, numerical simulations under Matlab/Simulink are presented in order to validate the efficiency of the energy management algorithm.

To ensure a good quality of electrical energy at all points of the distribution network, the grid operators install several static compensators of reactive power (STATCOM) and many active power filters at some common coupling points PCC. This paper focuses on the operation of a static converter connected at PCC point performing the function of a static compensator (STATCOM) in the case of a voltage drop exceeding the standards and ensuring the function of an active power filter (APF) in the opposite case. This static converter ensures the regulation of the PCC voltage and eliminates the current harmonics produced by the non-linear loads connected to the grid. The control laws are designed to allow the converter to switch between the operation of a STATCOM and an active power filter. Furthermore, this research article represents an important aspect in scientific research concerning the control of FACT devices. A static reactive power compensator (STATCOM) for reactive power control and an active power filter (APF) performance are investigated by Improved Virtual flux based Direct Power Control (IVF_DPC). The association of a static converter with the (IVF_DPC) control allows to react in a very fast time to the grid perturbations. Simulation results of an improved control scheme (IVF-DPC) for STATOM / APF are affected by MATLAB / Simulink software to demonstrate the dynamic performance of the proposed control strategy. The adopted control scheme is implemented using the dSPACE 1104 board. Real time implementation results prove the efficiency and uniqueness of the adopted strategy

The present paper aims to propose a real-time energy management strategy (EMS) based on two-phase interleaved buck-boost and boost converters for Fuel Cell/supercapacitor hybrid system. The interleaved converter (IC) is chosen to be applied in this work thanks to advantages, which presents compared to conventional DC/DC converter, as low input current ripples, a higher efficiency, a faster transient response, a reduced electromagnetic emission and an improved reliability. The proposed converters control strategies continuously support the EMS, based on frequency distribution to coordinate the hybrid power supply system, under variable load power conditions. In order to implement the proposed controllers, a laboratory test bench is applied to conduct experimental validation of the adopted structure. Experiments FC/SC hybrid system with the developed EMS was performed for variable load and the experiment waveforms of each power source are included. The obtained results suggest that the proposed energy management algorithm and the converters controllers present good performances.

This article deals with the control techniques of a low-voltage grid-connected to wind power conversion system based on a permanent magnet synchronous generator (PMSG) using an indirect matrix converter (IMC). Details of the proposed strategies for both the rectifier and inverter stages of the IMC are presented. Thus, a rectifier control strategy based on voltage-oriented control using space vector modulation is proposed. In addition, the control objective of the direct power control (DPC) inverter is the regulation of the active powers of the PMSG according to references established on the basis of the maximum power point tracker (MPPT) of the wind turbine, and also a good tracking of the output reactive power to its reference ensures unit power factor (UPF). A numerical simulation investigation is conducted to investigate the fast-dynamic performance of the proposed control systems during the wind speed variation. The obtained results in simulation are then complemented with tests in laboratory environment, the DPC control system is implemented on a dSpace DS1104 real time board. Selective experimental results are presented using a laboratory prototype of the wind energy conversion system to demonstrate the resulting improvements of the developed system. The results achieved have been clearly responded to the follow-up of references even under fluctuating wind conditions, and show promising relevance of the proposed method.

This paper investigates the steady-state and dynamic performance of three-phase Indirect Matrix Converter (IMC) used in wind energy conversion system (WECS) based on permanent magnet synchronous machine (PMSM). For the wind turbine, the proposed control is the maximum power point tracking algorithm based on optimum torque control loop (OTC). The voltage-oriented controller combined with space vector modulation (VOC-SVM) control algorithm is proposed. The validation of the modulation process is successfully performed. Simulation results present a good dynamic response and excellent performance and verify the effectiveness of the adopted control strategy of the IMC under wind speed variation.

This paper deals with an improved direct power control (DPC) of Doubly-Fed Induction Generator, the adopted approach applies a nonlinear sliding mode control (SMC) scheme to directly calculate the required rotor side converter's (RSC) control voltage. An improved stator flux estimation method is proposed, using an integrator scheme with a closed-loop dc offset compensation algorithm. The proposed strategy consists on an improved programmable low-pass filter. The theoretical principle of this method is discussed. Simulation results present a good dynamic response, an excellent performance and verify the effectiveness of the adopted strategy. Some experimental results are shown, in this paper, using a real time system controller based on dSpace 1104. Experimental results show the validity of the proposed control strategy.

Solving the problem of the energy management of a hybrid electric vehicle consists on finding the best distribution of the power to be supplied by the different energy sources. In this paper, a frequency separation based energy management is applied to distribute the missions of the energy sources while respecting their energy and dynamic limits. In our case, the system consists of three sources of energy. These three sources have different dynamic power / energy characteristics. Thus, a fuel cell is used as a main source and a hybrid storage system, consisting of a battery and a supercapacitor, is used as a secondary source allowing to support the primary one. The fuel cell provides the majority of the demand and the battery supports the FC during its start up and during high load demand (acceleration, high road slope). As the supercapacitor, it guarantees the response to pulse load requirements which is ensured by its fast dynamic. The proposed energy management strategy is evaluated for the New European driving cycle (NEDC). Simulation and experimental results are presented to prove the effectiveness of this strategy.

In this paper, we proposed a novel direct power control (DPC) strategy for a doubly fed induction generator (DFIG) used in wind energy generation system (WECS). Basing on estimated rotor flux position and the errors of the active and reactive power, the switching vectors for rotor side converter were selected from the switching table. The proposed method used a rotor flux observer which deals with a low-pass filter algorithm (LPF). Finally, the proposed control and system performances are evaluated through simulation under Matlab-Simulink. The obtained results of a DFIG system illustrated the robustness and the efficiency of the proposed control method DPC during wind speed variations and indicated that the control strategy is efficient and leads to the best performances. Some experimental results are presented, in this paper, using a realtime system controller based on dSpace 1104.