Alexandre De Bernardinis

Space-Vector PWM Control Synthesis for an H-Bridge Drive in Electric Vehicles

This paper deals with a synthesis of space-vector pulsewidth modulation (SVPWM) control methods applied for an H-bridge inverter feeding a three-phase permanent-magnet synchronous machine (PMSM) in electric-vehicle (EV) applications. First, a short survey of existing architectures of power converters, particularly those adapted to degraded operating modes, is presented. Standard SVPWM control methods are compared with three innovative methods using EV drive specifications in the normal operating mode. Then, a rigorous analysis of the margins left in the control strategy is presented for a semiconductor switch failure to fulfill degraded operating modes. Finally, both classic and innovative strategies are implemented in numerical simulation; their results are analyzed and discussed.

Corrective action with power converter for faulty multiple fuel cells generator used in transportation

This paper deals with the corrective action with a power converter for a 100kW multiple fuel cells (FC) generator under fault and used for vehicle propulsion, or high power onboard electrical assistance. The objective is to permit, through the power converter and its control strategy, a soft shut-down of a FC stack in fault and guarantee a continuous of operation at a reduced power, acceptable by the specifications. The power converter should also realize the power management during the degraded working situation. Two power system architectures are studied and compared by numerical simulation.

Fault detection and identification using simple and non-intrusive on-line monitoring techniques for PEM fuel cell

This paper scope is centered in the PEM fuel cell stack health diagnosis. For this purpose, authors present fault detection and identification methods using simple and non-intrusive on-line monitoring techniques. The approach is gradual based on detection and identification methods applied to a single cell up to multi-cells stacks used for power applications like transportation. A very low number of sensors are needed for the monitoring and the technique can be implemented on-line. Numerical simulation results illustrate the advantages of the different techniques.

Electrical architecture for high power segmented PEM fuel cell in vehicle application

In the objective of power increase for transport applications or on-board auxiliaries systems, long fuel cell stacks may be subject to disparities (fluidics, temperature) and can be the cause of possible failures. Coupled with a fault detection strategy, the power converter associated with the fuel cell can act to manage the fault. This article is about power converter topologies applied to a segmented high power fuel cell. The fuel cell generator is a 3-part segmented Polymer Electrolyte Membrane (PEM) fuel cell. Each fuel cell segment can be controlled independently according to its state of health (SoH). The converter topology has to be simple, compact, reliable and with a high efficiency. The resonant isolated boost as converter “technology brick”, allowing soft switching is a candidate topology to meet the technical specifications of the multi-port fuel cell-converter system.

Optimal traction and regenerative braking reference current synthesis for an IPMSM motor using three combined torque control methods for an Electric Vehicle

In this paper, we will represent the optimal traction and regenerative braking current synthesis for an IPMSM using three combined torque control methods for an Electric Vehicle (EV) using Matlab/Simulink®. In order to impose torque at higher speed, the flux should be weakened by injecting negative current in the d- axis. Several methods of reference current generation will be described according to the operating speed, torque reference, voltage and current constraints. The torque/speed characteristics will be decomposed into five zones of operation delimited by three methods of control: Maximum Torque per Ampere, Voltage Current Limited Maximum Torque and Constant Power Region.

Extended Braking Stiffness Estimation Based on a Switched Observer, With an Application to Wheel-Acceleration Control

In the context of hybrid anti-lock brake systems, a closed-loop wheel-acceleration controller based on the observation of the extended braking stiffness (XBS) is provided. Its objective is to improve the systems robustness with respect to changes in the environment (as changes in road conditions, brake properties, etc.). The observer design is based on Burckhardts tire model, which provides a wheel acceleration dynamics that is linear up to time-scaling. The XBS is one of the state variables of this model. This papers main result is an observer that estimates this unmeasured variable. When the road conditions are known, a 3-D observer solves the problem. However, for unknown road conditions, a more complex 4-D observer must be used instead. In both the cases, the observers convergence is analyzed using tools for switched linear systems that ensure uniform exponential stability (provided that a dwell-time condition is satisfied). Both experiments and simulations confirm the convergence properties predicted by the theoretical analysis.

Control strategy for extreme conditions regenerative braking of a hybrid energy storage system for an electric vehicle

This paper presents the regenerative braking design control and simulation of a hybrid energy storage system (HESS) for an electric vehicle (EV). The EV is driven by two 30 kW permanent magnet synchronous motors. The HESS contains a Li-Ion battery and an Ultra-Capacitor (UC) sources. In extreme braking conditions, the UC should be able to recover all the power delivered by the motors. When the maximal state of charge of the UC is achieved, the energy will be then recuperated by the battery. The introduction of a braking resistor would help the system to respect the voltage and current constraints and to protect the battery. This paper will validate the combination of the designed controllers ensuring the switching between the storage and dissipative elements while respecting the electrical constraints of the overall system, in particular for critical braking conditions. A Simulink model will be developed and validated.

Sensitivity analysis of the control of a three-phase open-end winding H-bridge drive

This work proposes a sensitivity analysis of the control of a 3-phase open-end windings PMSM H-bridge drive. The study issues are focused on the robustness of Space Vector PWM modulation strategies towards unavoidable operating faults. The considered faults are due to the imperfection of the PWM hardware implementation, the power converter nonlinearity and the harmonic distortion of the PMSM phase electromotive forces. This theoretical study is validated by experiments on a 3 H-Bridge drive test bench based on an induction motor.

Double resonant converter topology with fast switching semiconductors for lead-acid battery charger used in hybrid electric locomotive

This paper presents the study and experimental validation of a 9 kW lead-acid battery charger used to feed the 72V DC-Bus inside an hybrid electric locomotive demonstrator realized in the frame of the French research project PLATHEE (energy-efficient and environmentally friendly train platform). The proposed topology for the battery charger is a DC/AC/DC step-down converter structure using high frequency transformer and a double resonant series-parallel dipole. Main advantages of this topology are losses minimization due to soft switching operation, reduction of passive component weight and easy system integration. However, development and testing of the converter remain complex owing to high frequency constraints. Anti-parallel diodes of the DC/AC half-bridge dissipate losses in excess during switching sequences and their reverse recovery energy leads to constraining high current peaks. A solution consists in using fast Insulated Gate Bipolar Transistor (IGBT)/diode technology well suited to high frequency switching, and able to limit diode peak-current amplitude during switch-off. Electro-thermal endurance tests have been performed in order to characterize the thermal behavior of the semiconductor module and control its case temperature raise. The battery charger working has been first validated on laboratory test-bench using a battery emulator, and then implemented in the hybrid electric locomotive platform.

Energy management of a battery-flywheel storage system used for regenerative braking recuperation of an Electric Vehicle

This article proposes an energy recuperation management of a Hybrid Energy Storage System (HESS) during regenerative braking of an Electric Vehicle. The HESS is composed of a Li-Ion battery, and a high speed Flywheel Energy Storage (FES). At low speed, the integration of a controlled dissipative resistor is used to prevent battery overcurrent and overvoltage. At high speed, Voltage Current Limited Maximum Torque (VCLMT) control method is applied to reach the maximal speed allowed. Sizing of the flywheel and the design of the Permanent magnet synchronous motor (PMSM) control will also be presented. Simulation results show the dynamic behavior of the flywheel according to the PMSM desired control as well as the energy recovery strategy.