This paper presents and investigates planar and coaxial high frequency power transformers used for DC/DC converters in a three phase photo voltaic （PV） power systems. The winding structure including a Faraday shield...This paper presents and investigates planar and coaxial high frequency power transformers used for DC/DC converters in a three phase photo voltaic （PV） power systems. The winding structure including a Faraday shield between the primary and secondary windings is designed to minimize eddy current losses, skin and proximity effects, and to reduce the leakage inductance, and the inter winding coupling capacitance. Finite Element Method is employed to analyze the magnetic flux and eddy current distributions. The two different kinds of prototype high frequency transformers are designed and tested. The simulation and experiment results are demonstrated and compared with non-shielded transformers. The shielded transformers have achieved the expected results with a relatively small coupling capacitance, compared with the conventional high frequency transformer. This shield decreases the inter-winding coupling capacitance Cps. The topology of this shield has to be such that it acts as a Faraday screen while avoiding eddy current generation.展开更多
This paper introduces an isolated reversible DC-DC converter with a particular topology, which benefits from both the NPC （neutral point clamped） structure and the series-parallel connection of converters. The key p...This paper introduces an isolated reversible DC-DC converter with a particular topology, which benefits from both the NPC （neutral point clamped） structure and the series-parallel connection of converters. The key property of the proposed topology is the output voltage elevation above the blocking capabilities of each switch, without taking to a delicate synchronization of series-connected semiconductors. The converter is composed by two identical cells, each containing a full bridge, a medium frequency transformer and an NPC converter, connected in parallel at the input and in series at the output. The operation principle of each cell, into which a trapezoidal modulation was implemented, is similar to a DAB （dual active bridge）. A new model improves the dynamic performance of the controller. Simulation and experimental results verify the proposed topology, its control and start-up strategy.展开更多
Today, energy saving is one of the main objectives for engineers. In the case of mobile applications, energy can be saved by two different ways： decreasing the total masse of the system and increasing the efficiency ...Today, energy saving is one of the main objectives for engineers. In the case of mobile applications, energy can be saved by two different ways： decreasing the total masse of the system and increasing the efficiency of the overall system. This paper presents two optimization strategies to design a predefined multichannel structure of a boost converter which is dedicated to a solar airplane and used to interface PV panels and the battery system. The first strategy is a multi-criterion method that is able to trace the dependency between the converter＇s efficiency and its power density through the intermediary of the Pareto front. The second method, a mono-criterion approach, maximizes efficiency while respecting the constraint imposed on power density. The mono-criterion method that is applied to maximizing the European efficiency criterion showed that an increase in the number of channels enhanced the quantity of energy collected over a day by increasing the power density of the converter. At the end of the paper, the optimal design calculated was built to give an example of the result obtained by this design methodology. The results of the efficiency measurements made on a realized prototype are presented in this paper.展开更多
To extend the operating speed range of a conventional configuration of FESS （flywheel energy storage system）, an additional DC-DC boost converter is required between the machine and grid side converters to regulate ...To extend the operating speed range of a conventional configuration of FESS （flywheel energy storage system）, an additional DC-DC boost converter is required between the machine and grid side converters to regulate the output voltage. This paper presents a new FESS based on three-phase boost inverter topology. The proposed system facilitates voltage boost capability directly in a single-stage. The main advantage of the three-phase boost inverter is the deployment of only six switches and undersized passive elements to obtain a boosted AC output voltage weighed against the input DC supply. In this paper, FESS based on boost inverter topology is modeled and simulated using MATLAB/S1MULINK. An experimental setup has been built for the three-phase boost inverter to present its boosting capability. The simulation and experimental results sustain the proposed configuration.展开更多
文摘This paper presents and investigates planar and coaxial high frequency power transformers used for DC/DC converters in a three phase photo voltaic （PV） power systems. The winding structure including a Faraday shield between the primary and secondary windings is designed to minimize eddy current losses, skin and proximity effects, and to reduce the leakage inductance, and the inter winding coupling capacitance. Finite Element Method is employed to analyze the magnetic flux and eddy current distributions. The two different kinds of prototype high frequency transformers are designed and tested. The simulation and experiment results are demonstrated and compared with non-shielded transformers. The shielded transformers have achieved the expected results with a relatively small coupling capacitance, compared with the conventional high frequency transformer. This shield decreases the inter-winding coupling capacitance Cps. The topology of this shield has to be such that it acts as a Faraday screen while avoiding eddy current generation.
文摘This paper introduces an isolated reversible DC-DC converter with a particular topology, which benefits from both the NPC （neutral point clamped） structure and the series-parallel connection of converters. The key property of the proposed topology is the output voltage elevation above the blocking capabilities of each switch, without taking to a delicate synchronization of series-connected semiconductors. The converter is composed by two identical cells, each containing a full bridge, a medium frequency transformer and an NPC converter, connected in parallel at the input and in series at the output. The operation principle of each cell, into which a trapezoidal modulation was implemented, is similar to a DAB （dual active bridge）. A new model improves the dynamic performance of the controller. Simulation and experimental results verify the proposed topology, its control and start-up strategy.
文摘Today, energy saving is one of the main objectives for engineers. In the case of mobile applications, energy can be saved by two different ways： decreasing the total masse of the system and increasing the efficiency of the overall system. This paper presents two optimization strategies to design a predefined multichannel structure of a boost converter which is dedicated to a solar airplane and used to interface PV panels and the battery system. The first strategy is a multi-criterion method that is able to trace the dependency between the converter＇s efficiency and its power density through the intermediary of the Pareto front. The second method, a mono-criterion approach, maximizes efficiency while respecting the constraint imposed on power density. The mono-criterion method that is applied to maximizing the European efficiency criterion showed that an increase in the number of channels enhanced the quantity of energy collected over a day by increasing the power density of the converter. At the end of the paper, the optimal design calculated was built to give an example of the result obtained by this design methodology. The results of the efficiency measurements made on a realized prototype are presented in this paper.
文摘To extend the operating speed range of a conventional configuration of FESS （flywheel energy storage system）, an additional DC-DC boost converter is required between the machine and grid side converters to regulate the output voltage. This paper presents a new FESS based on three-phase boost inverter topology. The proposed system facilitates voltage boost capability directly in a single-stage. The main advantage of the three-phase boost inverter is the deployment of only six switches and undersized passive elements to obtain a boosted AC output voltage weighed against the input DC supply. In this paper, FESS based on boost inverter topology is modeled and simulated using MATLAB/S1MULINK. An experimental setup has been built for the three-phase boost inverter to present its boosting capability. The simulation and experimental results sustain the proposed configuration.
