Three-port Bidirectional DC-DC Converter Research Articles

A novel non-isolated three-port bidirectional DC-DC converter for off-grid solar-powered charging for electric and hydrogen vehicles using STM32 microcontroller

A novel non-isolated three-port bidirectional DC-DC converter for off-grid solar-powered charging for electric and hydrogen vehicles using STM32 microcontroller

A novel non-isolated three-port bidirectional DC-DC converter for off-grid solar powered charging for electric and hydrogen vehicle using STM32 microcontroller

A novel non-isolated three-port bidirectional DC-DC converter for off-grid solar powered charging for electric and hydrogen vehicle using STM32 microcontroller

Steady-state output characteristics of a three-port bidirectional DC-DC converter with dead time

This paper introduces a transformer-coupled three-port three-bridge half-bridge bidirectional DC-DC converter with dead time phase shift control. The converter consists of a high-frequency three-winding transformer and three independent half-bridge circuits. The half bridge is coupled through a transformer to provide galvanic isolation for all power ports. The converter uses phase shift control to achieve energy flow control through pulse width modulation (PWM). By controlling the gate pulse by PWM, the control of the dead time is realized, and the dead time can effectively suppress the straight-through phenomenon of the switch in the multi-port system, which can reduce power consumption and protect the power device. Through mathematical derivation, a detailed theoretical analysis of the three-port steady-state output characteristics with dead time is carried out. A typical application of the proposed converter is an electric vehicle auxiliary power supply system with a photovoltaic cell/auxiliary battery/power battery. The effectiveness of the proposed converter was verified by MATLAB simulation software.

A Battery Energy Storage System Assisted EV Charger Based on a Three Port DCDC Converter

In order to achieve a faster charging speed to the electric vehicle by a charger supplied with a limited capacity AC source, a battery energy storage system assisted EV charger based on a non-isolated three-port bidirectional dc-dc converter is proposed in this paper. The converter can work in single input single output, single input dual output, and dual input single output modes. It has the advantages of simple structure and flexible control. The working modes of the charger and the converter is described firstly. Then the working principles of the converter are analyzed and followed by the description of a three layer control system. An experimental prototype was built to test the converter. The experimental results show that the converter can work properly in the proposed modes.

AN ISOLATED THREE-PORT BIDIRECTIONAL DC-DC CONVERTER FOR PV BATTERY APPLICATION

this paper anisolated three-port bidirectional DC-DC converter for Photovoltaic (PV) battery application is presented. This converter is capable of parallel power management of various renewableenergy sources. The proposed converter is designed for controlling power of photovoltaic panel, load and rechargeablebattery. The advantage of this converter is it utilizes less number of controllable switches and provides soft switching for converter primary switch. This is achieved by an inductor-capacitor-inductor resonant circuit. This converter has ability to control the battery power when there is a low and extra power according to load, and also to control maximum power point tracking for PV system. MATLAB Simulink software is used for simulation studies. Simulation results shows that irrespective of variation in solar radiation this converter is capable of maintain constant output DC link voltage by managing power between two sources.

Comparative Analysis and Optimization of Power Loss Based on the Isolated Series/Multi Resonant Three-Port Bidirectional DC-DC Converter

Based on the loss distribution and efficiency analysis, a comparative study between a series resonant three-port bidirectional DC-DC converter (SR-TBC) and a multi-resonant three-port bi-directional DC-DC converter (MR-TBC) is reported here. By using the Fourier equivalent analysis method in hand, the resonant current, switching current expressions, zero voltage soft switching (ZVS) conditions of MR-TBC and SR-TBC are deduced. Besides, in consideration of efficiency and soft switching aspects, the loss models of main power components and resonant elements are integrated and optimized for both topologies. Their loss distributions are established, and the different effects derived from the adoption of SiC MOSFET and Si MOSFET on the converter efficiency are discussed. Finally, to verify the theoretical analyses, comparative experiments under diverse load states are conducted based on the prototypes of the MR-TBC and SR-TBC. The obtained results demonstrate that the MR-TBC successfully broadens the ZVS range and thus achieves higher efficiency along the entire load range.

Extending the power transfer capability of a three‐port DC–DC converter for hybrid energy storage systems

Design considerations for a three-port bidirectional DC-DC converter to be used in hybrid energy storage systems (HESSs) with the aim to increase the power transfer capability are discussed in this study. For this, an analysis of the power flow that allows obtaining the current waveforms is presented. Then, a loss model, that includes losses in semiconductors and the magnetic core, is proposed based as a function of the voltage variations in the energy storage devices considering all possible cases of power transference. The analysis reveals that it is possible to size the converter auxiliary inductances to reduce the converter currents and losses and therefore increase the power transfer capability. The analysis and the proposal presented in this study are validated using a 5-kW experimental prototype. Results show that it is possible to increase the converter transfer capability up to 80%.

An Isolated Three-Port Bidirectional DC-DC Converter with Enlarged ZVS Region for HESS Applications in DC Microgrids

In this paper, a two-stage three-port isolated bidirectional DC-DC converter (BDC) for hybrid energy storage system (HESS) applications in DC microgrids is proposed. It has an enlarged zero-voltage-switching (ZVS) region and reduced power circulation loss. A front-end three-phase interleaved BDC is introduced to the supercapacitor (SC) channel to compensate voltage variations of SC. Consequently, wide ZVS range and reduced circulation power loss for SC and DC bus ports are achieved under large-scale fluctuating SC voltage. Furthermore, a novel modified pulse-width-modulation (PWM) and phase-shift (PHS) hybrid control method with two phase-shift angles is proposed for BA port. And it contributes to an increasing number of switches operating in ZVS mode with varying battery (BA) voltage. Phase shift control with fixed driving frequency is applied to manage power flow. The ZVS range as well as the current stress of resonant tanks under varying port voltages is analyzed in detail. Finally, a 1 kW prototype with peak efficiency of 94.9% is built, and the theoretical analysis and control method are verified by experiments.

Auxiliary Inductances Design of a Bidirectional Three-Port DC-DC Converter

This paper proposes a methodology to design the auxiliary inductances of a bidirectional three-port DC-DC converter, which allows minimize the currents through the high frequency transformer and switches. In this way, RMS current and also the current values at the switching instants, as function of auxiliary inductances, are analyzed considering the different operating conditions. From this analysis, design considerations for these inductances are determined. Finally, experimental results are presented to validate the theory

Extensión del Rango de Operación con Conmutación Suave de un Convertidor CC-CC Bidireccional de Tres Puertos

The behavior of a three-port bidirectional DC-DC converter (TPC) under soft-switching mode applied to hybrid electric systems is analyzed in this paper. The principle of power flow control and the operation under soft-switching mode have been studied to establish the converter operation regions. The parameters considered are the transformer turns ratio and the leakage inductances, which establish the maximum power that can be transferred. As a result, design considerations to operate the TPC under soft-switching mode within a wide operation range, by using the conventional modulation strategy, are presented. Experimental results are included to validate the proposal.

An Integrated Three-Port Bidirectional DC–DC Converter for PV Application on a DC Distribution System

In this paper, an integrated three-port bidirectional dc-dc converter for a dc distribution system is presented. One port of the low-voltage side of the proposed converter is chosen as a current source port which fits for photovoltaic (PV) panels with wide voltage variation. In addition, the interleaved structure of the current source port can provide the desired small current ripple to benefit the PV panel to achieve the maximum power point tracking (MPPT). Another port of the low-voltage side is chosen as a voltage source port interfaced with battery that has small voltage variation; therefore, the PV panel and energy storage element can be integrated by using one converter topology. The voltage port on the high-voltage side will be connected to the dc distribution bus. A high-frequency transformer of the proposed converter not only provides galvanic isolation between energy sources and high voltage dc bus, but also helps to remove the leakage current resulted from PV panels. The MPPT and power flow regulations are realized by duty cycle control and phase-shift angle control, respectively. Different from the single-phase dual-half-bridge converter, the power flow between the low-voltage side and high-voltage side is only related to the phase-shift angle in a large operation area. The system operation modes under different conditions are analyzed and the zero-voltage switching can be guaranteed in the PV application even when the dc-link voltage varies. Finally, system simulation and experimental results on a 3-kW hardware prototype are presented to verify the proposed technology.

A New Kind of Bi-Directional Three-Port DC-DC Converter for Vehicle

This paper presents the design of a new bi-directional DC-DC converter topology, which solves the problem that electric vehicle could not run consistently both in time and distance. This DC-DC converter topology has three ports, each of which can transmit electric power to another port independently, By adopting the suggested method, the running time of the electric vehicle can be extended. Moreover, the topology uses phase shift control, indicating that the IGBT can be achieved by soft-switching technology. It enables us to reduces the current stress and switching loss considerably. Finally, this paper uses Simulink module of Matlab to simulate the process, and shows the experimental result. And the result shows us the DC-DC converter has great efficiency.

Asymmetrical Duty Cycle Control and Decoupled Power Flow Design of a Three-port Bidirectional DC-DC Converter for Fuel Cell Vehicle Application

This paper proposes a new asymmetrical duty cycle control method for a three-port bidirectional DC-DC converter with two current-fed ports interfacing with low voltage battery and ultracapacitor in a fuel cell vehicle. Along with the phase shift control managing the power flow between the ports, asymmetric duty cycle is applied to each port to maintain a constant DC bus voltage at low voltage side, which as a result will achieve wide zero-voltage-switching (ZVS) range for each port under varied ultracapacitor and battery voltages. The ZVS range analysis of different duty cycle control methods as well as the circulation power loss between the ports have been analyzed. In addition, the power flow design featuring the reduced coupling factors between the ports have been developed for the three-port bidirectional DC-DC converter. A fuel cell vehicle power train including a 2.5 kW three-port DC-DC converter interfacing a 12 V battery and ultracapacitor was built in the laboratory. The proposed asymmetrical duty cycle control and power flow design was implemented and verified on the hardware test bed under urban driving cycle. The experimental results validated that proposed asymmetrical duty cycle method has higher efficiency than other methods; furthermore, they also validated the reduced coupling factor between phase shift control and duty cycle control.

An Isolated Three-Port Bidirectional DC-DC Converter With Decoupled Power Flow Management

An isolated three-port bidirectional dc-dc converter composed of three full-bridge cells and a high-frequency transformer is proposed in this paper. Besides the phase shift control managing the power flow between the ports, utilization of the duty cycle control for optimizing the system behavior is discussed and the control laws ensuring the minimum overall system losses are studied. Furthermore, the dynamic analysis and associated control design are presented. A control-oriented converter model is developed and the Bode plots of the control-output transfer functions are given. A control strategy with the decoupled power flow management is implemented to obtain fast dynamic response. Finally, a 1.5 kW prototype has been built to verify all theoretical considerations. The proposed topology and control is particularly relevant to multiple voltage electrical systems in hybrid electric vehicles and renewable energy generation systems.

Transformer-Coupled Multiport ZVS Bidirectional DC–DC Converter With Wide Input Range

Multiport dc-dc converters are particularly interesting for sustainable energy generation systems where diverse sources and storage elements are to be integrated. This paper presents a zero-voltage switching (ZVS) three-port bidirectional dc-dc converter. A simple and effective duty ratio control method is proposed to extend the ZVS operating range when input voltages vary widely. Soft-switching conditions over the full operating range are achievable by adjusting the duty ratio of the voltage applied to the transformer winding in response to the dc voltage variations at the port. Keeping the volt-second product (half-cycle voltage-time integral) equal for all the windings leads to ZVS conditions over the entire operating range. A detailed analysis is provided for both the two-port and the three-port converters. Furthermore, for the three-port converter a dual-PI-loop based control strategy is proposed to achieve constant output voltage, power flow management, and soft-switching. The three-port converter is implemented and tested for a fuel cell and supercapacitor system.