Mamadou Baïlo Camara

DC/DC Converter Design for Supercapacitor and Battery Power Management in Hybrid Vehicle Applications—Polynomial Control Strategy

This paper presents supercapacitor (SCAP) and battery modeling with an original energy management strategy in a hybrid storage technology. The studied dc power supply is composed of SCAPs and batteries. SCAPs are dimensioned for peak power requirement, and batteries provide the power in steady state. A bidirectional dc/dc converter is used between SCAPs and the dc bus. Batteries are directly connected to the dc bus. The originality of this study is focused on SCAP behavior modeling and energy management strategy. The proposed strategy is based on a polynomial (RST) controller. For reasons of cost and existing components (not optimized) such as batteries and semiconductors, the experimental test benches are designed in reduced scale. The characterized packs of SCAPs include two modules of ten cells in series for each one and present a maximum voltage of 27 V. The proposed strategy is implemented on a PIC18F4431 microcontroller for two dc/dc converter topology controls. Experimental and simulation results obtained from the polynomial control strategy are presented, analyzed, and compared with that of classical proportional-integral control.

DC/DC and DC/AC Converters Control for Hybrid Electric Vehicles Energy Management-Ultracapacitors and Fuel Cell

This paper presents the ultracapacitors and the fuel cell (FC) connection for hybrid electric vehicles (HEVs) applications. An original method for the embedded energy management is proposed. This method is used to share the energetic request of the HEV between the ultracapacitors and the FC. The ultracapacitors are linked to dc-bus through the buck-boost converter, and the FC is connected to dc-bus via a boost converter. An asynchronous machine is used like traction motor or generator, and it is connected to dc-bus through an inverter. A dc-motor is used to drive the asynchronous machine during the decelerations and the braking operations. The main contribution of this paper is focused on the embedded energy management based on the new European drive cycle (NEDC), using polynomial control technique. The performances of the proposed control method are evaluated through some simulations and the experimental tests dedicated to HEVs applications.

Use of Ultracapacitors and Batteries for Efficient Energy Management in Wind–Diesel Hybrid System

The interconnection of the wind generator (WG) and the diesel generator (DG) induces some interactions on the common coupling point. These interactions are studied in this paper with the aim of identifying the system limits in performance and proposing an alternative solution. Due to the fast fluctuations of the WG and the DG slow dynamics, ultracapacitors and batteries are used for improving the hybrid system performances and reducing the fuel consumption. The dc-bus voltage is controlled by the diesel engine while providing a smoothed current. To ensure optimized life cycle cost and performance, a lifetime-estimation-based method is proposed. In this method, a rainflow counting method is applied to size the storage devices by taking into account the actual conditions of the system operation. The experimental test bench is designed in a reduced scale. Some simulations and experimental results are presented and analyzed.

Energy Management in the Decentralized Generation Systems Based on Renewable Energy—Ultracapacitors and Battery to Compensate the Wind/Load Power Fluctuations

This paper presents the energy management for the decentralized generation systems (DGS) using the wind turbine with photovoltaic (PV) panels and the energy storage devices. For a high penetration level of the wind/PV generation, the energy storage device with a fast response is necessary to cover the shortfall or overflow of generation due to sudden variations of the wind or the sun. In addition, the requested energy by the residential appliances presents random behavior, which can be lower or higher than the produced energy from the renewable sources. Using the wind turbine and the PV power generation system with energy storage will reduce the fluctuations of the wind power and the load ones. The energy storage system requires capital investment; thus, it is important to estimate the reasonable storage capacities without an overflow size for the desired applications. In addition, a good strategy for energy management is necessary to reduce the variation impacts of the wind energy and the load for the battery and the residential appliances. The contribution of this paper is focused on energy management based on the frequency approach using the wind/loads fluctuating power sharing and the polynomial controllers. First, this method enables reducing for the battery and the microgrid the impacts of the microcycles due to the wind/loads power fluctuations. Second, it allows estimating the energy storage capacity without the overflow size. The performances of the proposed method are evaluated through some simulations and experimental tests using the summer load profile and the winter ones.

Energy Management Based on Frequency Approach for Hybrid Electric Vehicle Applications: Fuel-Cell/Lithium-Battery and Ultracapacitors

This paper presents the ultracapacitors (U) and fuel-cell/lithium-battery connection with an original energy management method for hybrid electric vehicle (HEV) applications. The proposed method is focused on the frequency approach to meet the load energy requirement. The ultracapacitors are connected to the dc link through a buck-boost converter, and the fuel cell is connected to the dc link via a boost converter for the first topology. In the second topology, the lithium battery is connected to the dc link without a converter to avoid the dc-link voltage control. An asynchronous machine is used like the traction motor; it is related to the dc link through a dc/ac converter (inverter). The main contribution of this paper is focused on HEV energy management according to the dynamics (frequency) of the hybrid sources using polynomial correctors. The performances of the proposed method are evaluated through some simulations and the experimental tests, using the New European Driving Cycle (NEDC). This study is extended to an aggressive test cycle, such as the U.S. driving cycle (USDC), to understand the system response and the control performances.

Polynomial Control Method of DC/DC Converters for DC-Bus Voltage and Currents Management—Battery and Supercapacitors

This paper presents an embedded energy share method between the high energy storage system (battery) and the auxiliary energy storage system such as supercapacitors (SC). Using the SC and battery with a good strategy for energy management improves the performance of hybrid electric vehicles (HEVs). The SC modules are dimensioned for peak power requirement, and the batterys module ensures the average power of HEVs. The battery module is connected to dc-bus through a dc/dc converter for the first topology and without a converter for the second configuration. Buck-boost converters are used between the SC and the dc-bus to manage the available energy for all topologies. The originality of this paper stems from its focus on the control methods of the dc-bus voltage and currents, which use adjustable polynomial controllers (correctors based on polynomial approach). These methods are implemented in the PIC18F4431 microcontroller which ensures analog to digital conversion, and the pulsewidth modulation signals generation for dc/dc converters. Due to cost and available components, such as the power semiconductors (IGBT) and the battery, the experimental tests benches are carried out in reduced scale. Through some simulations and experimental results, the performance of the proposed control is shown and analyzed.

DC-bus voltage control for multi-sources systems - Battery and Supercapacitors

This paper deals the Battery-Supercapacitors energy management for Hybrid Electric Vehicles (HEV) applications. This idea is due to the present trend in the HEV applications, knowing that the major drawback in these last is the energetic autonomy problems. In this context, using Battery-Supercapacitors with a good strategy for embedded energy management is a promising solution to improve the systems performances. The main contribution of this paper is focused on DC-bus voltage and currents control based on the polynomial controller. The experimental control strategy is implemented in PIC18F4431 microcontroller for energy management through DC/DC converters. Through some simulations and experimental results obtained in reduced scale, the authors present an improved energy management strategy for HEV applications.

Permanent Magnet Synchronous Generators for Offshore wind energy system linked to Grid -Modeling and Control Strategies

This paper describes the modeling and control of Permanent Magnet Synchronous Generator (PMSG) of 5MW for wind farms applications. The generators are linked to the grid by means of a fully controlled frequency converter, which consists of two three phase rectifiers, an intermediate DC-bus, and an inverter. The full system is connected to AC grid with phase to phase RMS voltage of 20kV. Proposed control strategies include the Maximum Power Point Tracking (MPPT) for the PMSG speed control, the active/reactive power control, and the DC-bus voltage management. To show the performances of the control strategies, some simulation results are presented and analyzed using Matlab/Simulink software.

Modeling and control of the offshore wind energy system based on 5MW DFIG connected to grid

This paper presents the control strategies of an offshore wind energy system based on 5MW Doubly Fed Induction Generator (DFIG). The DFIG seems to be interesting for such high power wind generator systems. The proposed control strategies include the Maximum Power Tracking (MPPT) for the DFIG speed control, the active/reactive power control, and the DC-bus voltage control method. To show the performances of the control strategies, some simulation results are presented and analyzed using Matlab/Simulink software.

Energy management in the decentralized generation systems based on renewable energy sources

The DC distribution in the multisource systems seems to be a reasonable solution because the supplied energy is in the DC form for several sources, such as the photovoltaic panels (PV), the batteries, and the Ultracapacitors. Additionally, the major parts of the used electronics devises in the buildings operate with the DC current, such as computers, air conditioning, and multimedia. Based on these remarks, the authors propose an energy management method for the decentralized energy generation systems. The studied system includes the renewable energy sources (wind energy, and photovoltaic panels), the energy storage devices (lithium-battery, and Ultracapacitors), a programmable DC-Source for the Diesel generator behavior emulation, and the electronics load which emulate the electrical energy consumption in the building. Contrary to the previously works, the proposed control method is focused on the residential micro-grid energy management according to the dynamic responses of the sources and their availability. The performances of the method are evaluated through some simulations and the experimental tests, dedicated to residential micro-grid applications.