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Your search keyword '"Chen, Zhangyong"' showing total 9 results
Start Over Author "Chen, Zhangyong" Search Limiters Full Text Publication Year Range Last 3 years Publication Type Periodicals
9 results on '"Chen, Zhangyong"'

1. Hybrid Control Strategy Dual Resonance Core-Based Step-Up/Down Switched Capacitor Converter With Reduced Frequency Range for Wide Output Voltage Application

Author

Chen, Zhangyong, Han, Yubo, Wu, Yunfeng, Lu, Zhengdong, Liu, Xiangyu, and Zhang, Changhua

Abstract

Wide voltage range converters are significant for photovoltaic power generation system, battery charging, and auxiliary power source, etc. Resonant converter has been preferred topology for these applications, however, some demerits exist: 1) difficult to realize wide voltage gain range and low circulating current losses; 2) widely regulated switching frequency to adapt to wide voltage gain range; and 3) poor regulation at light load. Based on abovementioned shortcomings, dual resonance core-based step-up/down switched capacitor converter topology is presented in this article. Utilizing hybrid control strategy, nonoverlapping control strategy is used in the buck-type mode and overlapping control strategy is applied in the boost-type mode with common switching frequency range, and therefore, reduced frequency range in the presented converter is achieved. Moreover, wide voltage gain range can be obtained due to step-up/down capacity in the proposed converter. Furthermore, conversion ratio of proposed converter can be reduced to zero theoretically by using dual resonance core existed in the resonant switched capacitor converter. Finally, comprehensive operational principle analysis and performance analysis are provided, and a 48 to 28−90 V/100-W prototype is built to verify the analysis.

Published
2024
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3. Small Signal Modeling and Transient Cross-Regulation Analysis of Peak-Current-Mode-Controlled SIDO Buck LED Driver

Author

Wang, Yao, Xu, Jianping, Chen, Zhangyong, and Qin, Fuban

Abstract

Single-inductor dual-output (SIDO) dc–dc converter has been applied to light-emitting diode (LED) drivers with its advantages of small volume and low cost. Peak-current-mode (PCM) control of the SIDO converter has the advantages of fast transient performance and suppressed cross-regulation. A PCM-controlled SIDO buck LED driver to achieve independent dimming and to eliminate the steady-state cross-regulation is proposed in this article. The circuit and the principle of the PCM-controlled SIDO buck LED driver are presented, and its small signal model is established based on inductor current ripple. Furthermore, based on control-to-output loop gain transfer functions, control parameters of PCM-controlled SIDO buck LED driver are designed to achieve independent output current regulation of each LED driver. Besides, cross-regulation transfer functions are obtained to investigate the effect of reference signals and control parameters on the transient cross-regulation. Moreover, the effect of capacitor parameters on the stability of the LED driver is analyzed based on the bifurcation diagram. Finally, experimental results are provided to show the independent dimming capability of PCM-controlled SIDO buck LED driver with designed parameters, and the validity of the theoretical analysis on transient cross-regulation and stability of the LED driver.

Published
2023
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4. Adaptive Fast Fault Location for Open-Switch Faults of Voltage Source Inverter

Author

Meng Li, Haoran Yin, Yong Chen, and Chen Zhangyong

Subjects
Variable (computer science), Computer science, Control theory, Phase (waves), Embedding, Hardware_PERFORMANCEANDRELIABILITY, Electrical and Electronic Engineering, Dead time, Fault (power engineering), Fault detection and isolation, Threshold voltage, Voltage
Abstract

In this paper, the issue of open-switch faults of voltage source inverter (VSI) is studied, an adaptive fast voltage-based real-time open-switch fault location method is proposed. Firstly, for each switching period, the voltage deviation is calculated by the expected voltage and estimated actual voltage, they are obtained via the mixed logical dynamic model (MLDM) and measured currents, respectively. Then, the voltage deviation of each phase is employed as a fault variable. By this way, avoiding the use of additional hardware, and embedding easily in system. Furthermore, considering the impact of sampling error, parameter error, dead time, delay time, and transition time, the adaptive threshold is designed. Finally, simulations and experiments are executed to verify the effectiveness of the proposed method.

Published
2021

5. Reinforcement Learning Based Efficiency Optimization Scheme for the DAB DC–DC Converter With Triple-Phase-Shift Modulation

Author

Weihao Hu, Jian Xiao, Qi Huang, Zhe Chen, Chen Zhangyong, Frede Blaabjerg, and Yuanhong Tang

Subjects
Reinforcement Learning (RL), Maximum power principle, Computer science, DAB DC-DC converter, 020208 electrical & electronic engineering, 02 engineering and technology, Inductor, Power (physics), Control and Systems Engineering, Modulation, Control theory, Q-learning, 0202 electrical engineering, electronic engineering, information engineering, Reinforcement learning, Electrical and Electronic Engineering, power efficiency, optimization, Phase modulation, Electrical efficiency, Voltage
Abstract

Aim to improve the power efficiency of the dual-active-bridge (DAB) dc–dc converter, an efficiency optimization scheme with triple-phase-shift (TPS) modulation using reinforcement learning (RL) is proposed in this article. More specifically, the Q-learning algorithm, as a typical algorithm of the RL, is applied to train an agent offline to obtain an optimized modulation strategy, and then the trained agent provides control decisions online in a real-time manner for the DAB dc–dc converter according to the current operating environment. The main objective is to obtain the optimal phase-shift angles for the DAB dc–dc converter, which can achieve the maximum power efficiency by reducing the power losses. Moreover, all possible operation modes of the TPS modulation are considered during the offline training process of the Q-learning algorithm. Thus, the cumbersome process for selecting the optimal operation mode in the conventional schemes can be circumvented successfully. Based on these merits, the proposed efficiency optimization scheme using the RL can realize the excellent performances for the whole load conditions and voltage conversion ratios. Finally, a 1.2-KW prototyped is built, and the simulation and the experimental results demonstrate that the power efficiency can be improved by using the optimization scheme based on the RL.

Published
2021

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