Lionel Vido

Control of a Hybrid Excitation Synchronous Generator for Aircraft Applications

This paper deals with the control of a hybrid excitation synchronous generator which is used to supply an isolated grid for aircraft applications. This grid is supposed to be a 270-V dc bus. Thus, a rectifier is required between the machine and the dc bus. A diode rectifier is preferred here due to its great reliability and because it is also a low-cost solution. A controller is then proposed in order to regulate the output dc voltage of the generator. It is finally validated by simulations and experimental results.

Homopolar and bipolar hybrid excitation synchronous machines

This paper presents a description and operating principle of different hybrid excitation synchronous machines. Four prototype machines of different power rating (3 kW and 15 kW) have been studied. These machines combine two flux sources: permanent magnets, located in the rotor, and field coils, located in the stator. Thanks to this particular configuration the air gap flux can be easily controlled, without any risk of magnets demagnetisation. Tests are performed on the prototype machines to asses their flux weakening capability. Three of prototype machines are modular and can be assembled to have a homopolar or a bipolar configuration. These two configurations are compared using experimental measurements. The advantages and drawbacks of each configuration are described

Compared performances of homopolar and bipolar hybrid excitation synchronous machines

This paper presents a description, operating principle and experimental study of two hybrid excitation synchronous machines in motor and generator modes. These machines combine two flux sources: permanent magnets, located in the rotor, and field coils, located in the stator avoiding sliding contacts. Thanks to this particular configuration the air gap flux can be easily controlled, without any risk of magnets demagnetisation. Two machines are thoroughly studied in this paper. They have the same stator but different rotors. Tests are performed on the prototype machines to assess their flux weakening capability, torque (motor mode), output power (generator mode) and efficiency characteristics. The first prototype has a homopolar configuration whereas the second one has a bipolar configuration. These two configurations are compared using experimental measurements. The advantages and drawbacks of each configuration are also reported.

PM and hybrid excitation synchronous machines: Performances comparison

In this paper, a new topology of hybrid excitation synchronous machine (HESM) is presented. This kind of machine is well suited for hybrid vehicle applications. First of all, a summary description of the HESM is presented. A simplified analytic study based on reluctant network is presented. It is validated by finite element analysis and experimental measurements. The mechanical performances of the presented HESM are compared to a conventional permanent magnet synchronous machine (PMSM) designed for the same application.

Hybrid excitation synchronous motor control in electric vehicle with copper and iron losses minimization

This paper presents an optimal current control for the hybrid excitation synchronous motor in electric vehicle application. The control aims to meet the torque and speed requirements while insuring minimal copper and iron losses. Extended Lagrange multipliers optimization method (Kuhn-Tucker conditions) is used to elaborate analytical expressions for the optimal reference armature currents as well as for the field current if with respect to armature current and voltage constraints. Simulation over the new European driving cycle proves that the proposed optimal control leads to the lowest losses compared to the results obtained by other synchronous motor control strategies.

Magnetic equivalent circuit model of a hybrid excitation synchronous machine

Purpose – The purpose of this paper is to present an analytical modeling based on lumped parameter magnetic circuits of a hybrid excitation synchronous machine. The model is first established and compared with 3D finite elements analysis and measurements. It is then used to optimise hybrid excitation effectiveness.Design/methodology/approach – The machine studied, which has a 3D structure, requires the use of 3D finite elements method. The 3D FEA tool is still time‐consuming, which limits its use in optimal design process. To overcome this limitation the paper investigates an analytical modeling based on lumped parameter magnetic circuits. The developed model is then used in an optimisation procedure.Findings – The machine presented has an original structure. It has been subject to a patent protection. The operating principle of this structure has been presented and optimisation of hybrid excitation effectiveness has been investigated. Double excitation allows one to control air gap flux while reducing pe...

Control of a DC generator based on a Hybrid Excitation Synchronous Machine connected to a PWM rectifier

This paper deals with the control of an hybrid excitation synchronous generator which is used to supply an isolated grid for aircraft applications. This grid is supposed to be a 270 V DC bus. Thus, a rectifier is required between the machine and the DC bus. Two structures can be used: diode or PWM rectifier. Here, only the structure with a PWM rectifier is studied. With a such system, it is possible to use a vector control applied to the structure in order to obtain minimal copper losses in the machine. The controller is synthesized here using a methodology based on a graphical representation of the system and then it is validated by simulation

3D magnetic equivalent circuit model for homopolar hybrid excitation synchronous machines

A 3D magnetic equivalent circuit model is developed to predict the total excitation flux of an homopolar hybrid excitation synchronous machines. It is established using the main flux path and a part of the magnets leakage fluxs path. This model takes into account the lamination effect and ferromagnetic parts reluctances. Results from the model are compared with finite-element predictions and the obtained results are similar.

Control of a hybrid excitation synchronous generator connected to a diode rectifier supplying a DC bus

This paper deals with the modeling and the control of the hybrid excitation synchronous machine (HESM) connected to a diode bridge rectifier. The set is operating as a DC generator that supplies an isolated grid in embedded applications such as aircraft electrical power generation. Saturation effects have also been taken into account. The aim of the control is to maintain the DC bus voltage constant when the load and/or the speed of the rotor vary. Simulation results validate this approach.

Photovoltaic motors review, comparison and switched reluctance motor prototype

The simplicity of photovoltaic motors makes them ideal candidates for fully autonomous applications requiring thousands of operating hours without maintenance, like water pumping. Photovoltaic motors use photovoltaic cells optically commutated by a shutter driven by the motor rotor to convert light energy into mechanical energy, without the need of any brushes or other power electronics. With the decrease of photovoltaic cells price, photovoltaic motors could be more affordable and reliable than conventional systems, and therefore particularly well suited for off-grid applications. The concept has been patented under various forms, but the scientific literature is so far very scarce. In this article, we attempt to classify photovoltaic motors, and to explain in details their physical working principle. Then we compare the different architectures by defining two pre-design factors linked to the system maximal output power. Finally, we report first experimental results on a photovoltaic switched reluctance motor (PV SRM) prototype using a 6/4 switched reluctance machine and 12 photovoltaic cells.