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This paper proposes a digital online efficiency optimization technique for DC/DC Dual Half-Bridge Series Resonant Converters. The proposed technique implements an advanced modulation scheme which exploits the degrees of freedom inherently available in the converter modulation space in order to simultaneously regulate the output voltage and maintain the system in its maximum efficiency point. Furthermore,...
A traditional Voltage Source Inverter (VSI) has higher efficiency than a Current Voltage Source (CSI) due to the less conduction power loss. However, the reverse recovery of the free-wheeling diode limits the efficiency improvement for the silicon devices based hard-switching VSI. The traditional quasi-soft-switching inverter can alternate between VSI and CSI by using a proper control scheme and thereby...
With an imperative demand of clean and reliable electricity generation in some countries, the increasing adoption of new photovoltaic (PV) systems pushes the Distribution System Operators (DSOs) to expand the transmission/distributed lines. However, the potential cost brought by such extensions and increased maintenances introduce new obstacles. In view of this concern, the DSOs starts to reduce PV...
A PWM or quasi-square-wave (QSW) zero-voltage-switching (ZVS) non-isolated boost converter using enhancement-mode GaN (eGaN) FETs is reported in this paper. The new converter topology requires small number of passive components, minimizes the converter switching loss under high-voltage high-frequency operations, and offers low-voltage stress across power transistors. A transformer-based floating gate...
In this paper, an autonomous photovoltaic (PV) power generation/storage system connected to an AC nonlinear load is investigated. Depending on the load demand, the PV output power and the battery condition, five modes of operation are feasible with the changing load power. The steady-state analysis of the system for the entire operating modes is presented. Based on the concept of controllability sensitivity,...
SiC devices exhibits improved performances in terms of switching speed and reduced on-state voltage drop, especially if a high-voltage and high-temperature environment is considered. In this paper the impact and opportunities of using high-voltage SiC switching devices in a pulsed power supply oriented to domestic induction heating applications is analyzed. Considering the converter requirements,...
This paper develops a three-phase front-end power conversion stage for data center power supplies based on 400 Vdc power delivery architecture, which has been proven to have higher efficiency than traditional AC architectures. The front-end stage is based on three paralleled three-phase current source rectifiers, which have several benefits for this application. A control method is introduced for...
The Dual Active Bridge (DAB) converter with the Conventional Phase-shift Modulation (CPM) and Triangular Current Modulation (TCM) are compared in terms of the power transfer and total loss. It is noted that there exists an optimal design trade off among the switching loss, conduction loss and drive loss according to different load current and switching frequency. Therefore, the optimal switching frequency...
GaN HEMT devices exhibit improved performance in terms of switching speed and reduced on-state resistance, especially if low-voltage and high-frequency conditions are considered. In this paper, a high-power density quasi-resonant converter is proposed in order to improve both the maximum output power and the maximum operating frequency with GaN HEMT devices. Since the proposed converter operates as...
Conventionally, both the primary side and the pickup side need series or shunt capacitor compensation to increase transmission efficiency in a wireless power transfer system. In this paper, a wireless power transfer system with an active resonance circuit is proposed. Comparing the diode based rectifier on the pickup side in traditional wireless power transfer systems, a PWM rectifier is exploited...
This paper presents the first, off chip, class DE (resonant half bridge) converter working in the Very High Frequency (VHF) range. The benefits of using half bridge circuits both in the inverter and rectifier part of a VHF resonant dc/dc converter are analyzed and design equations for all components in the power stage are given. The circuit has been simulated to verify the accuracy of the presented...
This paper presents a new power conversion architecture for single-phase grid interface. The proposed architecture is suitable for realizing miniaturized ac-dc converters operating at high frequencies (HF, above 3 MHz) and high power factor, without the need for electrolytic capacitors. It comprises of a line-frequency rectifier, a stack of capacitors, a set of regulating converters, and a power combining...
This work presents the analysis of the behavior of a modular system of DC/DC converters with input-series output-series connections. The goal is to explore a simple solution that provides a stable operation by connecting totally independent converters working in DCM, except one of them (working in CCM) that determines the input-output voltage ratio. This alternative can be applicable when the input...
In this paper, motor drive system fed by single phase diode rectifier without Power Factor Correction (PFC) circuit is proposed. The motor drive considered in this paper consists of single phase diode rectifier, three-phase inverter, and small DC-link capacitor. Since DC-link capacitor is small, grid input current of the diode rectifier can be directly affected by electrical output power of the inverter...
This paper presents an islanded AC microgrid composed of multi-DGs and an energy storage system. The point of common coupling (PCC) frequency and voltage magnitude are controlled by the ESS while other DGs can export active power and reactive power independently. A nonlinear energy management control strategy is proposed by utilizing the PCC frequency as an agent for all constituent units, which avoids...
The purpose of this paper is to outline the effects of dye-sensitised solar cell (DSSC) configuration on useable output power provided through low-power, step-up DC-DC converters. It is shown that by connecting DSSCs in series rather than in parallel, higher power conversion efficiency is achieved due to increased cell voltage, and this in turn results in higher power delivery. Limitations to varying...
Maintaining a reliable operation in microgrids has significant importance. One factor required for the reliable microgrid operation is to keep certain energy reserve without sacrificing the cost for satisfying any load variation. Reliability and cost optimization of photovoltaic and fuel cell based microgrid system is investigated in this paper. A typical residential load is considered in order to...
This paper presents operation and control of a Squirrel Cage Induction Generator (SCIG) to generate power from an oscillating point absorber based wave energy conversion (WEC) system. The oscillating point absorber buoy is assumed to be connected with the SCIG through a rack and pinion gear arrangement, thus converting the linear motion of the buoy to rotary motion of the generator. Proper gear ratio...
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