S. Caux

Pressure, flow and thermal control of a fuel cell system for electrical rail transport

This paper presents the flow, pressure and temperature control of a fuel cell used in high power rail transport. We present modeling and control approach of the proton exchange membrane fuel cell and its auxiliaries. This work shows that we can characterize and adjust the system control on an operating cycle using the established simulation tools, not only to follow the requested power trajectories but also to control voltage, pressure and temperature of all elements to not be destructive.

Design of robust controllers for PMSM drive fed with PWM inverter with inertia load variation

A detailed design and comparison of PID and state space controller (SSC) for permanent magnet synchronous motor (PMSM) loaded with elastic joint to a mass are presented. The SSC controller consists of a LQ controller and a proportional feedback compensation of the load torque estimated by a reduced disturbance observer. Step by step analyse for PID and LQ tuning is conduced for PMSM drive and varying load. A large load inertia variation is taken into account to define the strategies used to calculate the optimum PID, LQ and reduced observer parameters that ensure the drive system stability and performances. Simulations results verify and compare the robustness of the controllers. Complexity of synthesis and performances obtained are discussed on a PMSM drive fed with a PWM voltage inverter controlled in current

PEMFC air loop model and control

This paper presents the control of air supply of a proton exchange membrane fuel cell-PEMFC-system. This control is based on a species balance model in the cathode (oxygen) compartment which must be controlled to stay not only at a constant pressure but also to follow a desired air flow. Desired air flow combined with sufficient hydrogen flow enables the production of a maximal desired current for electrical load. In the context of a transport application (Tramway in this paper) pressure is increased from atmosphere to 1.5 bar absolute, with a controlled compressor. The moto-compressor group is based on a screw type compressor driven with a permanent magnet synchronous machine fed with a pulse width modulation inverter. The non linear drive control structure is described and the compressor characteristics is used to have an accurate control of the air loop supply allowing to let the fuel cell in their own settings and to furnish power following the desired power profile.

Energy management of fuel cell system and supercaps elements

Abstract The use of Fuel Cell and Supercaps as energy elements in transport application is now a reality. Having two power sources on board allows a certain energy management strategy. Defining this strategy some iteration must be made with an accurate model to extract the optimal solution. In order to reduce computation time consumption, a simplified physical fuel cell model is proposed. This model is used in algorithms to compute the two power references of the two sources allowing the minimum hydrogen consumption and maximum braking energy absorption for a tramway following an actual power demand.

Simplified electrical model tuned for actual controlled PEMFC

Using fuel cells in combination with other sources as energy elements in transport application is now a reality. Having, at least, two power sources on board, requires an efficient energy management strategy. Most of these energy management strategies are model-based. In order to reduce computation time consumption for such a global simulator, simplified models must be established. Such a simplified physical fuel cell model is thus proposed in this work. A complete model is studied in simulation to derive a simpler model tuned not only with the simulator parameters but also with parameters identification made on an actual fuel cell. Results obtained on current and voltage behaviors, following an actual requested power demand, are accurate enough to use the proposed model in iterative optimization algorithms

Design of robust PID controllers for PMSM drive with uncertain load parameter

Permanent magnet synchronous motor (PMSM) drive systems coupled to elastic loads may exhibit instability and poor performance under mechanical uncertainties. Two techniques for tuning the speed controller of a PMSM drive system are proposed and compared in this paper. The first technique is based on the frequency domain and the other exploits evolutionary programming concepts like genetic algorithm. Complexity of both tuning techniques, simulation and experimental results are discussed for PMSM drive system fed with current regulated PWM voltage source inverter.

Computer Aided Thought Process for Robust PMSM Control

Permanent magnet synchronous machines are commonly used with a pulse width modulated inverters to obtain easy to use variable speed actuators. Such drive systems may be applied to different types of mechanical loads. The inverter must feed the machine with a sinusoidal current controlled in magnitude and phase to obtain a brushless behavior. Robust speed control techniques must be implemented when the mechanical load is uncertain or to maintain the performance whenever the load changes. This paper points out that internal torque/current control must be effective before tuning a speed controller. Thought process is explained step by step and is computer aided. The design of the different control loops are made in simulation with optimization approach or robust formulation. Due to DSP development the implementation on the actual device is described and controllers are tested easily.

SIMPLIFIED FUEL CELL SYSTEM MODEL IDENTIFICATION

Abstract The use of fuel cell and supercaps as energy elements in transport application is now a reality. Having two power sources on board allows a certain energy management strategy. In order to reduce computation time consumption, a simplified physical fuel cell model is proposed. An accurate model is studied in simulation to derive a simpler model. The simplified model is used with parameters identification made on an actual fuel cell. Results obtained on current and voltage, with an actual power demand, are sufficient to use the proposed model in iterative optimization algorithms.

Robust sensorless tuning of a PMSM drive with 2D experimental designs

This paper presents an original application of the experimental designs method to a PMSM drive control without mechanical sensors. The position, velocity and back emf observer used is a redundant observer structure. This observer includes different gains and filters that have to be tuned optimally for the best convergence performance. The proposed method is based on the statistic analysis of parameter influence on a defined performance criterion. The most influent parameters and their optimal levels are identified. A new two dimensional design is also carried out for a robust tuning of the observer coefficients, in order to reject the influence of the parameter variations. This analysis is called cross product plan and highly reduces the number of required experiments.