In this paper, a design by optimization process is used to size a 10-kW three-phase pulse width modulation (PWM) inverter for aeronautic application. The objective function is the converter weight, which has to be minimized. Sizing constraints are the efficiency, alternating current (AC) and direct current (DC) harmonics, and thermal constraints on all devices. A deterministic algorithm is chosen since it allows obtaining quick results and dealing with a large number of variables. All equations are analytical, in order to comply with this gradient-based optimization strategy, which imposes the derivability of the models. Several optimization results using different AC inductor solutions (iron powder and ferrite) are compared. The optimized converters were built and tested experimentally to verify their performances. Semiconductor and inductor losses were measured accurately using calorimetric test benches. The optimality of the solutions was carefully verified by changing parameters.

Single-stage isolated and bidirectional (SSIB) AC–DC converters have a high potential for future solid-state transformers and smart battery chargers due to their reduced volume and high efficiency. However, there is a research gap for SSIB reactive power injection. This article introduces an SSIB three-phase AC–DC converter composed of three low frequency rectifiers linked by tiny film capacitors with a quad-active-bridge series-resonant (QABSR) DC–DC. A novel QAB modulation is proposed to solve three issues: (1) Three DC inputs with high ripple compensation, (2) active–reactive power injection, and (3) minimization of high-frequency (HF) transformers currents. The rectified grid voltages were modulated by time-variant duty ratio (DR) angles. In contrast, the DC source was modulated by a fixed DR (FDR) angle along with a phase-shift angle which changes according to the grid current amplitude. A constant HF current amplitude with minimum value was obtained. It is shown that the HF current amplitude is increased for reactive power injection. Hence, the FDR angle was used to compensate for this increase. Active and reactive power control were validated in a 2 kW prototype. Compared with other structures, tiny DC-link capacitors and smaller L filters were used. Moreover, higher efficiency (96%) and smaller grid currents THDi (3%) were obtained.

In this paper, a contactless power transfer system is presented. It is designed to supply piezoelectric actuators with a low frequency signal and a DC offset. A power electronic structure based on a full bridge PWM inverter, a resonant capacitor, an inductive rotating transformer which works at low frequencies and the piezoelectric actuator is presented and modeled. The behavior of the system is analyzed regarding the variation of the transformer’s coupling coefficient and the resonant capacitor value. Then, an optimization tool is presented where magnetic and power properties of the system are optimized in terms of electrical performances and volume. An embedded passive electronic system, that creates the mandatory DC offset for the actuator, is shown. Experimental results obtained with the prototype are exposed and compared to the simulations. Based on these results, a new version with a secondary quasi-resonant topology has been studied allowing both to reduce the size of the transformer and the global efficiency.

This paper presents an accurate model of series parallel resonant converter with capacitive output filter. Thanks to this analytic study, it is possible to determine rapidly and easily the steady state. Furthermore a design methodology is proposed to choose series and parallel resonant frequencies in order to optimize the behavior of the converter. Simulations are used to demonstrate the accuracy and to check the design methodology.