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In modern aircraft designs, there is a need for new high power isolated DC/DC converters. Full bridge derived topologies are appropriate for these specifications. Aircraft specifications are demanding and a high power density is needed. In order to decrease volume, reactive component, such as the transformer have to be optimized in volume, weight and loses. High frequency is needed to decrease inductive...
In this paper we propose the mode selection strategy of a multi-mode single-stage single-phase inverter and the associated mode selection scheme for double-line-frequency power pulsation decoupling between the input an the output port for PV (photovoltaic) panel applications. Multiple modulation strategies are used along the line cycle to optimize the overall efficiency of the converter. The proposed...
In modern telecommunication systems, the requirements for amount of transmitted data are increasing rapidly. For a better spectral efficiency complex type modulations (QaM, OFDM) are used, resulting in high PAPR signals. As a consequence, if conventional linear amplifiers (classes A, B) are used in transmitters, prominent linearity, but poor efficiency are assured. The efficiency of the transmitters...
This paper presents a new modulation for modular multilevel converters (MMC) based on a simple idea, which is very easy to implement. It consists of playing with the relative behaviour of each phase in order to obtain the desired AC voltage. This method also assures that the voltage capacitor in each sub-module remains constant. Moreover, this converter allows the operation of the system under unbalanced...
In aircraft applications, there has been an increasing trend related with the More Electric Aircraft (MEA), which results in rapid rise in the electrical power demand on-board. One of its goals lies in minimizing weight and volume of the electrical subsystem while maintaining good power quality and efficiency. The main purpose of this paper is to present and analyze an electrical design of a three-phase...
In modern communication system, both the bandwidth and peak-to-average power ratio of the transmitted signal are increasing rapidly. As a result, the power amplifiers based on linear power amplifiers such as class A, B or AB suffer from very low efficiency. The most promising solutions are the Envelope Tracking (ET) and Envelope Elimination and Restoration (EER) techniques, which can greatly improve...
This paper presents the modelling and control of a DC/DC bidirectional converter with 3 terminals based on Modular Multilevel Converter (MMC) suitable for high voltage and power applications in multi-terminals high voltage direct current (MT-HVDC) grids. A proof is given in order to guarantee the global stability of the system by means of Lyapunov theory and switching control theory. In addition,...
Nowadays there has been an important increase of electric equipment in modern aircraft which leads to a rising demand of electrical power. This highlights the necessity of efficient, reliable and high energy density power converters which rectify three-phase 115V ac to 270V dc for power distribution. This paper presents an isolated single-stage PWM rectifier with the integration of a current injection...
Modern microprocessors impose strict specifications on Voltage Regulating Modules (VRMs) with advanced features such as Dynamic Voltage Scaling (DVS) and Adaptive Voltage Positioning (AVP). In this study the Output Impedance Correction Circuit (OICC) concept is employed as an additional energy path in a Multiphase synchronous buck converter in a manner that, during the load steps transients, the output...
A Novel Three-Phase Rectifier topology based on the integration of a Buck type Rectifier and a Current Fed Full-Bridge is proposed. The main contribution of this rectifier topology with galvanic isolation is the integration of two stages, sharing the inductor, and the reduction of the inductor current ripple. The circuit is analyzed in detail. A 2 kW demonstrator prototype has been designed, built...
In this paper, physical modeling of a GaN HEMT is proposed, with the objective of device design optimization for application in a high frequency DC/DC converter. From the point of view of a switching application, physical model for input, output and reverse capacitance as well as for channel resistance is very important, since the aforementioned parameters determine power losses in the circuit. The...
Current trends in automotive industry impose as main drivers the improvement of the efficiency and the miniaturization of the electronic systems. New technologies for passives enable the integration of the power converter together with the load in a single chip. This study is related to the optimization and analysis of a PwrSoC Buck converter system used to supply in-chip load for automotive application...
In this paper, physical modeling of a GaN HEMT with a field plate structure is proposed, with the objective of providing the connection between the physical design parameters of the device (geometry, Al mole fraction, type of the field plate, etc) and on-resistance together with parasitic capacitances of the device. In this way, it is possible to optimize the design of a switching device for a particular...
Using multiphase technique is interesting in PV AC-module application due to light-load efficiency improvement by applying phase shedding, and the possibility of low-profile implementation. This paper presents a comparison, in terms of size and efficiency, of the parallel interleaved and the parallel-series connected multiphase configurations, as a function of the number of phases, for a forward micro-inverter...
This paper presents the modeling and control of a DC/DC bidirectional converter suitable for medium voltage and power applications in Multi-Terminals HVDC (MT-HVDC) grids. Moreover its use as DC circuit-breaker is described. This is a new concept, against the contemporary studies of DC breakers, which could help for the implementation of MT-HVDC networks. The proposed multilevel topology is based...
In this work it is presented a design tool to estimate the figures of merit of a radiofrequency power amplifier (RFPA) based on the envelope amplifier (EA) design for an EER (Envelope Elimination and Restoration) application. Using as the input data the transfer function of a buck derived converter for an envelope amplifier application, the main figures of merit of the complete amplifier can be obtained...
Current trends in automotive industry impose as main drivers the improvement of the efficiency and the miniaturization of the electronic systems. New technologies for passives enable the integration of inductor based power converter together with the load in a single chip. Due to the complexity of the system and various constraints, multi-variable optimization needs to be employed. This study presents...
This paper presents a primary-parallel secondary-series multicore forward micro-inverter for photovoltaic AC-module application. The proposed solution changes the number of active phases depending on the grid voltage, thus enabling the usage of low-profile unitary turns ratio transformers. Therefore, the transformers are well coupled and the overall performance of the inverter is improved. Due to...
This paper addresses the power delivery strategy on an aircraft application consisting on seven isolated DC loads to be supplied from the AC grid. Distributed or centralized power processing is evaluated taking into account weight and efficiency. Additionally, the rectifier switching frequency has to be synchronized with an external frequency clock to minimize the interference of the converter harmonics...
Conventional three-phase rectifiers are controlled to achieve good power factor and low THD in the input. In the case of pulsating power loads, the fast dynamic response implies that the load pulses are reflected in the generator. These pulsating loads affect the life time operation of the generator, especially when it is not oversized (that is the case in aircraft applications). In order to smooth...
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