Phase-shifted Full-bridge DC-DC Research Articles

IoT-based real-time monitoring of supercapacitors used in electric vehicles

The research focuses on the condition monitoring of supercapacitor systems installed in the electric vehicle that acts as the power source for the vehicle when it needs high power for a lesser time. This research work aims to introduce the Internet of Things in battery systems along with supercapacitors aiming to increase the efficiency and reliability of the system. In the corresponding research work, IoT-based condition monitoring for a 48V supercapacitor for an electric vehicle is implemented, the supercapacitor is charged using the phase shift full bridge DC-DC converter after that the data is transferred from the Matlab Simulink to the Thingspeak platform to enable IoT based application Hence establishing the real-time monitoring of super- capacitor. Introducing the Internet of Things will help researchers in a deeper understanding of supercapacitor behavior in a real-time environment as well as the real-time data will be helpful in the protection of the system.

Research on the Intelligent Control Strategy of the Fuel Cell Phase-Shifting Full-Bridge Power Electronics DC-DC Converter

With the aggravation of energy problems, the development and utilization of new energy has become the focus of all countries. As an effective new energy, the fuel cell has attracted the attention of scholars. However, due to the particularity of proton exchange membrane fuel cell (PEMFC), the performance of traditional PI controlled phase-shifted full-bridge power electronics DC-DC converter cannot meet the needs of practical application. In order to further improve the dynamic performance of the converter, this paper first introduces several main topologies of the current mainstream front-end DC-DC converter, and analyzes their performance in the fuel cell system. Then, the operation process of the phase-shifted full-bridge power electronics DC-DC converter is introduced, and the shortcomings of the traditional PI control are analyzed. Finally, a double closed-loop adaptive fuzzy PI controller is proposed, which is characterized by dynamically adjusting PI parameters according to different working states to complete the intelligent control of phase-shifted full-bridge DC-DC converter. The simulation results in MATLAB/Simulink show that the proposed algorithm has good a control effect. Compared with the traditional algorithm, the overshoot and stabilization time of the system are shorter. The algorithm can effectively suppress the fluctuation of the output current of the fuel cell converter, and is a very practical control method.

Novel and simplified model representing Current-Output Phase-Shift Full-Bridge DC-DC LCLC Resonant Converter in Arc Welding Application

ABSTRACT In this paper, a novel and simplified model representing current-output phase-shift full-bridge DC-DC LCLC resonant converter in arc welding application is thoroughly presented. First, a switched model written in state space representation and featuring a bilinear form is proposed. The latter facilitates the derivation of both the reduced and full order averaged models in continuous conduction mode (ROAM and FOAM). Although the FOAM can be employed in linear or nonlinear control schemes and the derivation of steady state behavior, in this paper the ROAM is considered in designing both voltage mode control and current mode control by using the classical PID and the fractional order PID controllers. Simulation confirms that the switched model, ROAM and FOAM are quite accurate compared to the circuit simulation using SimPowerSystem toolbox of MATLAB/SIMULINK. Results clearly showed that depending on the switching frequency, the proposed topology can be applied either in constant voltage characteristic or dropped characteristic welding machines fulfilling either zero current Switching (ZCS) or zero voltage switching (ZVS). Besides, the fractional order PID controller seems to be more adapted for arc welding application than its traditional version.

Design of 2kW DC Charger for Two Wheelers

The demand for Electric Vehicles is increasing day by day. EVs are silent, nonpolluting and produce zero emissions. This paper presents the design of a dc charger that performs the necessary functions for charging EV battery. An EV charger is a component in EV environment that supplies power for recharging the EV battery. Usually, charging an electric car seems to be very simple process, implying that one can plug one’s car into a charger that is connected to the electric grid. However, it is not as that simple. It depends on the types of EVSE that one has deployed. Offboard DC Charger is connected to the premises wiring of the mains ac supply network .It is designed to be separate and operate entirely off the vehicle. In the offboard dc charger, direct current electrical power is delivered directly to the vehicle. The power module in a DC fast charger consists of an AC-to-DC rectifier converter and an isolated DC/DC converter. The AC-to-DC rectifier is power factor correction stage in which a Vienna Rectifier based PFC converter is used. The Isolated DC-DC Converter used here is the Phase Shift Full Bridge DC-DC converter. A 2 kW prototype of the offboard DC Charger is designed and simulated in MATLAB/Simulink R2018b.

Phase-Shifted Full-Bridge Zero Voltage Switching DC-DC Converter Design with MATLAB/Simulink Implementation

Design of phase-shifted full bridge zero voltage switching DC-DC converter has been very challenging due to circuit parasitic effect on the system dynamics. This paper presents steady-state analysis and iterative approach for the systemic design of phase-shifted full bridge DC-DC converter with improved dynamic performance and satisfactory operational requirement in terms of zero-voltage switching range, operating switching frequency and switching resonance. A 3 kW DC-DC converter is designed using the iterative design approach and the system dynamics performance was investigated in the MATLAB/Simulink environment. The converter zero-voltage switching simulation results were satisfactory with 90% efficiency under full load condition.

Stability Analysis of FCHEV Energy System Using Frequency Decoupling Control Method

Fuel cell (FC) is a promising power supply in electric vehicles (EV); however, it has poor dynamic performance and short service life. To address these shortcomings, a super capacitor (SC) is adopted as an auxiliary power supply. In this study, the frequency decoupling control method is used in electric vehicle energy system. High-frequency and low-frequency demand power is provided by SC and FC, respectively, which makes full use of two power supplies. Simultaneously, the energy system still has rapidity and reliability. The distributed power system (DPS) of EV requires DC-DC converters to achieve the desired voltage. The stability of cascaded converters must be assessed. Impedance-based methods are effective in the stability analysis of DPS. In this study, closed-loop impedances of interleaved half-bridge DC-DC converter and phase-shifted full-bridge DC-DC converter based on the frequency decoupling control method are derived. The closed-loop impedance of an inverter for permanent magnet synchronous motor based on space vector modulation control method is also derived. An improved Middlebrook criterion is used to assess and adjust the stability of the energy system. A theoretical analysis and simulation test are provided to demonstrate the feasibility of the energy management system and the control method.

The study of energy model and multi-period of discrete phase shift control technique for full-bridge DC-DC converter

Phase-shift full-bridge (PSFB) DC-DC converter benefits from high efficiency by zero-voltage switching turn-on of all switches without any additional auxiliary circuit, and PSFB DC-DC converter has been widely used in high power applications. In this paper, the operating mode of PSFB DC-DC converter is studied, and the energy iteration model of PSFB DC-DC converter is established. The discrete phase shift (DPS) control technique for PSFB DC-DC converter is proposed and discussed. Unlike the conventional PWM PSFB control technique, the DPS control technique uses two preset phase shift times tpsH and tpsL as control variables where 0tpsHtpsL ≤Tw with Tw being the switching period. When output voltage is lower than the reference voltage, phase shift time tpsH is selected, and a large duty cycle DH is obtained on the secondary side, which makes output voltage increase. Similarly, when output voltage is higher than the reference voltage, phase shift time tpsL is selected, and a small duty cycle DL is obtained on the secondary side, which makes output voltage decrease. With the energy iteration model, the energy iteration process is clearly revealed, steady-state and transient performances are studied. From the analysis results it can be known that the DPS controlled PSFB DC-DC converter always operates in a multi-periodic state. The simulation reasults show that the proposed control technique has an advantage over the conventional PWM PSFB control technique in simple design, great robust and excellent transient performance.

넓은 충전 범위를 갖는 전기 자동차용 급속 충전기의 고효율 운전을 위한 손실 분석

Power losses of a 1-stage DC-DC converter and 2-stage DC-DC converter are compared in this paper. A phase-shift full-bridge DC-DC converter is considered as 1-stage topology. This topology has disadvantages in the stress of rectifier diodes because of the resonance between the leakage inductor of the transformer and the junction capacitor of the rectifier diode. 2-stage topology is composed of an LLC resonant full-bridge DC-DC converter and buck converter. The LLC resonant full-bridge DC-DC converter does not need an RC snubber circuit of the rectifier diode. However, there is the drawback that the switching loss of the buck converter is large due to the hard switching operation. To reduce the switching loss of the buck converter, SiC MOSFET is used. This paper analyzes and compares power losses of two topologies considering temperature condition. The validity of the power loss analysis and calculation is verified by a PSIM simulation model.

A Controller Design for a Stability Improvement of an On-Board Battery Charger

This paper proposes the controller design for a stability improvement of an on-board battery charger. The system is comprised of a power factor correction (PFC) circuit and phase shift full-bridge DC-DC converter. The PFC circuit performs the control of the DC-link voltage and the input power factor. The DC-DC converter regulates the voltage and the current in the battery using the DC-link voltage. This paper proposes the design method of PI controller for the PFC circuit using a small signal model. The analysis and design of a type-three controller for the DC-DC converter is also presented. A simulation and experiment has been performed on the on-board battery charger and their results are presented to verify the validity of the proposed system.