Convertisseur de puissance par amplification magnetique pour application spatiale

The current Master's thesis studies the development of a power converter for space application using magnetic amplifiers. The objective is to eliminate or reduce the utilization of expensive radiation hardened MOSFET, while globally improve the robustness and reliability of the circuit.; The assumption that motivates such ambition is that the instantaneous variation of the inductor value leads to a predictable variation of the current flowing into it, in order to maintain the same quantity of energy stored inside. If a certain energy expense is necessary to change the inductance, but that the first is smaller than the energy moved in the electrical circuit, a control gain is achieved.; The current work analyzes this starting assumption. The studied variable inductor is a parametric transformer, which is used as a power switch in a DC-DC boost converter. The theoretical and experimental study of the power transfer cycle allows the determination of the amount of power required to change the inductance, and consequently to deduce the control gain. The mechanisms of variation of the inductance and the coupling inside the parametric transformer are also studied and verified experimentally. Finally, the analysis of the selected converter topology allows the predication of its performance from the circuit's parameters and the operating conditions.; The results are showing that a certain amount of energy must be spent to change the inductance. The electrical circuit can recuperate this expense, plus the diminution of the energy stored into the inductor. For the studied boost converter, this energy displacement leads also to an increase of the power transferred from the source to the load. However, this increase is less than the power drawn to change the inductance.; The observation of a control gain less than unity invalidate the expectation underlying the starting assumption, and allows to conclude that the magnetic amplifier cannot formally replace the transistor in the studied converter.; By studying this assumption, the current research work allowed to improve the knowledge surrounding magnetic amplifiers. This is paving the way to the development of novel converters for space application, taking at the same time the distinctive advantages of power semi-conductors and magnetics.