scholarly journals A DC-DC Center-Tapped Resonant Dual-Active Bridge with Two Modulation Techniques

Electronics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1699
Author(s):  
Gengxin Chen ◽  
Nuoman Xu ◽  
Li Yuan ◽  
Muhammad Humayun ◽  
Muhammad Mansoor Khan
Keyword(s):  
Frequency Modulation ◽  
Reverse Current ◽  
Resonant Converters ◽  
Soft Switch ◽  
Load Range ◽  
Dual Active Bridge ◽  
Switching Losses ◽  
Modulation Techniques ◽  
And Performance ◽  
Modulation Methods

Power converters with higher efficiency in a wide load range are important for reducing the overall energy consumption of renewable energy generation systems. A center-tapped LC series resonant dual-active bridge (LC-DAB) converter for DC-DC conversion is proposed in this paper. The proposed converter utilizes a center-tapped bridge to block reverse current and eliminate back flow power to reduce conduction losses. Two modulation methods for the proposed topology (i.e., fixed frequency modulation (FFM), and variable frequency modulation (VFM)) are proposed and analyzed. Both modulation methods can realize soft switch over the entire load range to reduce switching losses. In addition, the proposed modulation techniques guarantee soft switching for all devices and synchronous rectifier is realized by the center-tapped bridge to further reduce the conduction losses. Furthermore, a comprehensive comparison in terms of conduction losses and switching losses has been carried out to highlight the superiority of the proposed converter over the existing LC resonant converters. Finally, simulated and experimental results for a 1.5 kW prototype are presented to validate the theoretical analysis and performance of the proposed converter.

Optimal Simultaneous PWM Control for Three-Phase Dual-Active-Bridge Converters to Minimize Current Stress in the Whole Load Range

2020 ◽  
pp. 1-1
Author(s):  
Jiahao Sun ◽  
Lin Qiu ◽  
Xing Liu ◽  
Jian Zhang ◽  
Jien Ma ◽  
...  
Keyword(s):  
Pwm Control ◽  
Load Range ◽  
Current Stress ◽  
Dual Active Bridge ◽  
Three Phase

Research on Multi-Mode Controller of Switching Power Supply

2014 ◽  
Vol 568-570 ◽  
pp. 1217-1220
Author(s):  
Shu Lin Liu ◽  
Li Li Qi
Keyword(s):  
Power Supply ◽  
Switching Frequency ◽  
Switching Power Supply ◽  
Load Range ◽  
Heavy Load ◽  
Operating Modes ◽  
Switching Power ◽  
Advantages And Disadvantages ◽  
Switching Losses ◽  
Light Load

In order to improve the efficiency of the switching power supply in whole load range, the controller with PWM, PFM and BURST operating modes is designed in this paper, which changes the operation mode automatically according to the load. The operating principle and the advantages and disadvantages of the three operating modes are analyzed and compared. PWM mode is used in heavy load; PFM mode is used in light load to reduce switching losses by reducing the switching frequency and BURST mode is used at the standby time to further reduce switching losses. The main control module is designed and simulation results verify the feasibility of the designed circuit.

scholarly journals On the Practical Evaluation of the Switching Loss in the Secondary Side Rectifiers of LLC Converters

Energies ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5915
Author(s):  
Manuel Escudero ◽  
Matteo-Alessandro Kutschak ◽  
Francesco Pulsinelli ◽  
Noel Rodriguez ◽  
Diego Pedro Morales
Keyword(s):  
Resonant Frequency ◽  
High Voltage ◽  
Low Voltage ◽  
Hysteresis Loss ◽  
Resonant Converters ◽  
Switching Loss ◽  
Operating Modes ◽  
Switching Losses ◽  
Series Resonant ◽  
Secondary Side

The switching loss of the secondary side rectifiers in LLC resonant converters can have a noticeable impact on the overall efficiency of the complete power supply and constrain the upper limit of the optimum switching frequencies of the converter. Two are the main contributions to the switching loss in the secondary side rectifiers: on the one hand, the reverse recovery loss (Qrr), most noticeably while operating above the series resonant frequency; and on the other hand, the output capacitance (Coss) hysteresis loss, not previously reported elsewhere, but present in all the operating modes of the converter (under and above the series resonant frequency). In this paper, a new technique is proposed for the measurement of the switching losses in the rectifiers of the LLC and other isolated converters. Moreover, two new circuits are introduced for the isolation and measurement of the Coss hysteresis loss, which can be applied to both high-voltage and low-voltage semiconductor devices. Finally, the analysis is experimentally demonstrated, characterizing the switching loss of the rectifiers in a 3 kW LLC converter (410 V input to 50 V output). Furthermore, the Coss hysteresis loss of several high-voltage and low-voltage devices is experimentally verified in the newly proposed measurement circuits.

Drive modelling and performance estimation of IPM motor using SVPWM and Six-step Control Strategy

2021 ◽  
Keyword(s):  
Comprehensive Evaluation ◽  
Element Model ◽  
Torque Ripple ◽  
Performance Estimation ◽  
Smooth Transition ◽  
Motor Speed ◽  
Traction Motor ◽  
Modulation Techniques ◽  
And Performance ◽  
The Impact

This paper presents a comprehensive evaluation of the performance of an interior permanent magnet (IPM) traction motor drive, and analyses the impact of different modulation techniques. The most widely used modulation methods in traction motor drives are Space vector modulation (SVPWM), over-modulation, and six-step modulation have been implemented. A two-dimensional electromagnetic finite element model of the motor is co-simulated with a dynamic model of a field-oriented control (FOC) circuit. For accurate tuning of the current controllers, extended complex vector synchronous frame current regulators are employed. The DC-link voltage utilization, harmonics in the output waveforms, torque ripple, iron losses, and AC copper losses are calculated and compared with sinusoidal excitation. Overall, it is concluded that the selection of modulation technique is related to the operating condition and motor speed, and a smooth transition between different modulation techniques is essential to achieve a better performance.

Multi-Frequency Atomic Force Microscopy Combining Amplitude- and Frequency-Modulation Techniques

2012 ◽  
Vol 1422 ◽  
Author(s):  
Santiago D. Solares ◽  
Gaurav Chawla
Keyword(s):  
Atomic Force Microscopy ◽  
Frequency Modulation ◽  
Complementary Information ◽  
Control Loops ◽  
Force Microscopy ◽  
Atomic Force ◽  
Mode Of Operation ◽  
Modulation Techniques ◽  
Different Response ◽  
Amplitude And Frequency Modulation

ABSTRACTMulti-frequency atomic force microscopy (AFM) offers additional response signals in comparison to traditional dynamic AFM. Furthermore, depending on the mode of operation used, the higher eigenmode responses are generally not directly influenced by the topographical acquisition control loops, such that they can explore a fuller range of tip-sample interactions. In this work we describe the implementation of multi-frequency imaging schemes that enable the acquisition of topographical, phase and frequency shift contrast in tapping-mode operation. This type of characterization can be especially useful for soft, highly dissipative samples, such as polymers, for which the various response channels can exhibit significantly different response, thus providing complementary information. We discuss typical results obtained as well as important challenges that need to be addressed in order to develop a fully quantitative technique.

A Survey of Low Switching Frequency Modulation Techniques for Medium-Voltage Multilevel Converters

2015 ◽  
Vol 51 (5) ◽  
pp. 4212-4228 ◽  
Author(s):  
Amarendra Edpuganti ◽  
Akshay Kumar Rathore
Keyword(s):  
Frequency Modulation ◽  
Switching Frequency ◽  
Multilevel Converters ◽  
Medium Voltage ◽  
Modulation Techniques
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