Hamid Gualous

Supercapacitor Characterization and Thermal Modelling With Reversible and Irreversible Heat Effect

This paper investigates double layer capacitor (or supercapacitor) thermal modelling. The originality of this work resides in the fact that 4 type K thermocouples are inserted inside a 350 F supercapacitor modified cell. These thermocouples allow supercapacitor internal temperature measurement. Experimental results have shown that the electrical storage device temperature increases in the phase of charge and decreases during the discharge. The developed model takes into account the effect which is due to the reversible heat generation in the supercapacitor. The model is based on heat equation solution and allows temperature distribution determination inside and outside the supercapacitor as a function of the position and of the time. The model is developed for double layer capacitor based on activated carbon and organic electrolyte technology.

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.

Supercapacitor Thermal Modeling and Characterization in Transient State for Industrial Applications

A new thermal model, which allows temperature distribution determination inside a supercapacitor cell, is developed. The model is tested for a supercapacitor based on the activated carbon and organic electrolyte technology. In hybrid vehicle applications, supercapacitors are used as energy-storage devices, offering the possibility of providing the peak-power requirement. They are charged and discharged at a high current rate. The problem with this operating mode is the large amount of heat produced in the device which can lead to its destruction. An accurate thermal modeling of the internal temperature is required to design a cooling system for supercapacitor module, meeting the safety and reliability of the power systems. The purpose of this paper is to study the supercapacitor temperature distribution in steady and transient states. A thermal model is developed; it is based on the finite-differential method which allows for the supercapacitor thermal resistance determination. The originality of this paper is in the fact that a thermocouple (type K) was placed inside the supercapacitor from Maxwell Technologies. A test bench is realized. The cases of supercapacitor thermal distribution using natural and forced convection are studied. Simulations and experimental results are reported to validate the proposed model. The results obtained with this model may be used to determine the cooling system required for actual supercapacitor applications.

Supercapacitor ageing at constant temperature and constant voltage and thermal shock

This paper presents supercapacitor ageing according to the voltage, the temperature and thermal shock tests. To investigate this effect, a test bench of accelerated supercapacitor calendar ageing was carried out. Experimental tests are realized at constant temperature when the supercapacitors are polarized at the maximum voltage. To quantify the supercapacitor ageing, the equivalent series resistance (ESR) and the equivalent capacitance (C) are measured using the DC and AC characterization. To lead to the determination of the supercapacitor lifetime, Arrhenius law, that describes the effect of temperature on the velocity of a chemical reaction, is considered. Finally, experimental results of supercapacitor thermal shock are presented.

Calendar and cycling ageing of activated carbon supercapacitor for automotive application

Abstract This paper presents supercapacitor ageing as a function of voltage, temperature and charge/discharge cycling solicitations. To investigate their effects, a test bench of accelerated supercapacitor calendar and cycling ageing was carried out. Experimental tests are performed at constant temperature when the supercapacitors are polarized at the maximum voltage in the case of calendar ageing. In the case of cycling test, supercapacitors are charged and discharged at constant current. It can be noted that when the supercapacitors are charged and discharged at constant current the temperature of the supercapacitor increases and that the average voltage is not zero. To quantify the supercapacitor ageing, the equivalent series resistance (ESR) and the equivalent capacitance (C) are measured.

State-of-Charge and State-of-Health Lithium-Ion Batteries’ Diagnosis According to Surface Temperature Variation

This paper presents a hybrid state-of-charge (SOC) and state-of-health (SOH) estimation technique for lithium-ion batteries according to surface temperature variation (STV). The hybrid approach uses an adaptive observer to estimate the SOH while an extended Kalman filter (EKF) is used to predict the SOC. Unlike other estimation methods, the closed-loop estimation strategy takes into account the STV and its stability is guaranteed by Lyapunov direct method. In order to validate the proposed method, experiments have been carried out under different operating temperature conditions and various discharge currents. Results highlight the effectiveness of the approach in estimating SOC and SOH for different aging conditions.

Characterization of high-voltage IGBT module degradations under PWM power cycling test at high ambient temperature

The success of the high temperature power electronic applications depends on the power device reliability. The increasing thermal demands, like in hybrid electric cars, require power devices operating at junction temperatures above their common level of 125 °C. The thermal cycles generated in standard modules in such conditions induce several failure mechanisms in their package and chips. This article presents ageing tests of an EconoPIM IGBT module submitted to PWM power cycling at high ambient temperature. Several electrical and thermal parameters are monitored to detect failure onsets in the module components. Static and dynamic measurements are periodically made to reveal possible module characteristic drifts, and to better understand the effects of this kind of cycling test on the module static and switching behaviors. The follow-up of the dynamic parameter evolution represents the originality of this study.

An advanced energy management of microgrid system based on genetic algorithm

Immense growth has happened in the field of microgrid (MG) and the energy management system (EMS) methods in the past decade. It is estimated that there is still a huge potential of growth remaining in the field of EMS in the coming years. The main role of EMS is to autonomously determine hour-by-hour the optimum dispatch of MG and main grid energy to satisfy load demand needs. This paper is focused on developing an advanced EMS model able to determine the optimal operating strategies regarding to energy costs minimization, pollutant emissions reduction, MG system constraints and better utilization of renewable resources of energy such as wind and photovoltaic through daily load demand. The proposed optimization model of EMS is formulated and solved based on genetic algorithm (GA). The efficient performance of the algorithm and its behavior is illustrated and analyzed in detail considering winter load demand profile.

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.