scholarly journals A Novel Hybrid LDC Converter Topology for the Integrated On-Board Charger of Electric Vehicles

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3603
Author(s):  
Vu-Hai Nam ◽  
Duong-Van Tinh ◽  
Woojin Choi
Keyword(s):  
Low Voltage ◽  
Operating Conditions ◽  
Maximum Efficiency ◽  
Battery Charger ◽  
Forward Converter ◽  
Vehicle To Grid ◽  
Circulating Current ◽  
In Series ◽  
Converter Topology ◽  
Output Capacitor

Recently, the integrated On-Board Charger (OBC) combining an OBC converter with a Low-Voltage DC/DC Converter (LDC) has been considered to reduce the size, weight and cost of DC-DC converters in the EV system. This paper proposes a new integrated OBC converter with V2G (Vehicle-to-Grid) and auxiliary battery charge functions. In the proposed integrated OBC converter, the OBC converter is composed of a bidirectional full-bridge converter with an active clamp circuit and a hybrid LDC converter with a Phase-Shift Full-Bridge (PSFB) converter and a forward converter. ZVS for all primary switches and nearly ZCS for the lagging switches can be achieved for all the operating conditions. In the secondary side of the proposed LDC converter, an additional circuit composed of a capacitor and two diodes is employed to clamp the oscillation voltage across rectifier diodes and to eliminate the circulating current. Since the output capacitor of the forward converter is connected in series with the output capacitor of the auxiliary battery charger, the energy from the propulsion battery can be delivered to the auxiliary battery during the freewheeling interval and it helps reduce the current ripple of the output inductor, leading to a smaller volume of the output inductor. A 1 kW prototype converter is implemented to verify the performance of the proposed topology. The maximum efficiency of the proposed converter achieved by the experiments is 96%.

scholarly journals Coordinating Control of an Offshore LVDC Microgrid Based Renewable Energy Resources for Voltage Regulation and Circulating Current Minimization

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3384
Author(s):  
Walid Nassar ◽  
Olimpo Anaya-Lara ◽  
Khaled Ahmed
Keyword(s):  
Direct Current ◽  
Low Voltage ◽  
Voltage Regulation ◽  
Operating Conditions ◽  
Energy Resources ◽  
Renewable Energy Resources ◽  
Energy Unit ◽  
Electrical Grid ◽  
Dc System ◽  
Circulating Current

Multi-Use Platform (MUP) is a new topic addressed, extensively, under the EU funded projects that aim to exploit oceans in a sustainable way in order to reduce the costs of marine energy and to extract seafood. MUP’s electrical grid experiences many challenges, being offshore. One of these challenges is that only Alternating Current (AC) systems are considered which are inefficient, expensive and require bulky components. Considering the advantages of Direct Current (DC) systems, this paper aims to study the feasibility of using the DC system to improve the electrical infrastructure of the MUP’s grid. Floating energy unit comprising tidal, wind and solar energy resources is considered as a base unit for the MUP’s grid. The paper proposes a new distributed controller for grid voltage regulation and minimizing circulating current among parallel-connected floating energy units in an offshore Low Voltage Direct Current (LVDC) microgrid. A mathematical model is derived for n-parallel floating energy units with the proposed controller. Additionally, stability analysis for the overall model of a single floating energy unit is also presented. The analysis and simulation of the proposed DC system demonstrate that the system is stable and fault-rejected at different operating conditions.

scholarly journals A Novel Multilevel Bidirectional Topology for On-Board EV Battery Chargers in Smart Grids

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3453 ◽  
Author(s):  
Rafael Leite ◽  
João Afonso ◽  
Vítor Monteiro
Keyword(s):  
Smart Grids ◽  
Operating Conditions ◽  
Control Algorithms ◽  
Battery Charger ◽  
Multilevel Converters ◽  
Vehicle To Grid ◽  
Battery Chargers ◽  
Grid Side ◽  
Grid Side Converter ◽  
Laboratory Prototype

This paper proposes a novel on-board electric vehicle (EV) battery charger (EVBC) based on a bidirectional multilevel topology. The proposed topology is formed by an AC-DC converter for the grid-side interface and by a DC-DC converter for the battery-side interface. Both converters are interfaced by a split DC-link used to achieve distinct voltage levels in both converters. Characteristically, the proposed EVBC operates with sinusoidal grid-side current, unitary power factor, controlled battery-side current or voltage, and controlled DC-link voltages. The grid-side converter operates with five voltage levels, while the battery-side operates with three voltage levels. An assessment, for comparison with classical multilevel converters for EVBCs is considered along the paper, illustrating the key benefits of the proposed topology. As the proposed EVBC is controlled in bidirectional mode, targeting the EV incorporation into smart grids, the grid-to-vehicle (G2V) and vehicle-to-grid (V2G) operation modes are discussed and evaluated. Both converters of the proposed EVBC use discrete-time predictive control algorithms, which are described in the paper. An experimental validation was performed under real operating conditions, employing a developed laboratory prototype.

Research on Four-Phase Interleaved Step-Up DC/DC Converter for Photovoltaic Energy Storage System

2019 ◽  
Author(s):  
Xiaogang Wu ◽  
Boyang Yu ◽  
Jiuyu Du ◽  
Wenwen Shi
Keyword(s):  
Energy Storage ◽  
Output Voltage ◽  
Storage System ◽  
Energy Storage System ◽  
Maximum Efficiency ◽  
Boost Converters ◽  
Photovoltaic Energy ◽  
Wide Range ◽  
In Series ◽  
Output Capacitor

Intended for the high voltage gain and wide-range operation of DC/DC converters for photovoltaic energy storage systems, a topology for four-phase interleaved DC/DC converters for photovoltaic power generation is proposed. This topology increases output voltage for output in series, and reduces the input current ripple by paralleling the input. Compared with traditional boost converter topology, the proposed topology reduces the output current and output voltage ripple, reduces the stress of the switching device, and reduces the withstanding voltage of the output capacitor under the premise of ensuring the boost ratio. Experimental results show that the maximum efficiency of the converter reaches 95.37%. Compared with traditional boost converters, the proposed converter offers obvious advantages in efficiency under the conditions that the output voltage and load are variable.

scholarly journals A Control Strategy for Bidirectional Isolated 3-Phase Current-Fed Dual Active Bridge Converter

Electronics ◽  
2018 ◽  
Vol 7 (10) ◽  
pp. 214 ◽  
Author(s):  
Dong-Min Lee ◽  
Seung-Wook Hyun ◽  
Jin-Wook Kang ◽  
Yong-Su Noh ◽  
Chung-Yuen Won
Keyword(s):  
Pulse Width Modulation ◽  
Soft Switching ◽  
Zero Voltage Switching ◽  
Phase Current ◽  
Dual Active Bridge ◽  
Circulating Current ◽  
Operation Techniques ◽  
Simulation And Experiment ◽  
Output Capacitor ◽  
Zero Voltage

This paper examines the characteristics of the zero voltage switching (ZVS) and zero voltage transition (ZVT) soft-switching applied in the 3-phase current fed dual active bridge (3P-CFDAB) converter, which combines the advantages of the dual active bridge (DAB) converter and current-fed full bridge (CFFB) converter. When an active clamp circuit is added to the CFFB converter, the circuit configuration of the DAB converter is shown in part of the entire circuit. This allows the use of pulse width modulation (PWM) techniques which combine the PWM techniques of both the DAB converter and CFFB converter. The proposed converter performs both duty and phase control at the same time in order to reduce the circulating current and ripple current of the output capacitor, which are the disadvantages of the CFFB converter and DAB converter. In addition, the ZVS and ZVT soft switching areas were analyzed by means of the phase current and leakage inductor current in each transformers. To verify the principle and feasibility of the proposed operation techniques, a simulation and experiment were implemented with the 3P-CFDAB.

scholarly journals Determining the environmental indicators for vehicles of different categories in relation to CO2 emission based on road tests

2017 ◽  
Vol 170 (3) ◽  
pp. 66-72
Author(s):  
Jerzy MERKISZ ◽  
Łukasz RYMANIAK
Keyword(s):  
Co2 Emissions ◽  
Operating Time ◽  
Environmental Indicators ◽  
Operating Conditions ◽  
Si Engine ◽  
Propulsion Systems ◽  
System A ◽  
In Series ◽  
Series Configuration ◽  
Ci Engine

The article discusses the possibility of determining the environmental indicators for vehicles of different categories in relation to CO2 emissions. These are called toxicity indicators because they concern the compounds: CO, THC and NOx. Three Euro V compliant vehicles with different propulsion systems types were used for the study: a 0.9 dm3 urban passenger car with a SI engine and a start-stop system, a 2.5 dm3 off-road vehicle with a CI engine, and a city bus with a hybrid drive system in series configuration and a CI engine with a displacement of 6.7 dm3. Measurements were made in actual operating conditions in the Poznan agglomeration using a portable emissions measurement system (PEMS). The paper presents the characteristics of the operating time shares of vehicles and propulsion systems as well as CO2 emissions depending on the engine load and crankshaft rotational speed for individual vehicles. The determined toxicity indicators allowed to indicate their usefulness, to make comparisons between tested vehicles, and to identify directions for further work on the application and interpretation of these indicators.

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