通讯机构：
[Chen, WG ] U;Univ South China, Sch Elect Engn, Hengyang 421001, Peoples R China.
关键词：
Bipolar pulse;Marx circuit;narrow pulsewidth;pulse power supply;step recovery diode (SRD)
摘要：
In ultrawideband (UWB) ground-penetrating radar systems, there is a mutual constraint between a narrow pulsewidth and the high amplitude of pulse signal sources, which stimulates the development of pulsed power sources. To overcome the limitation, this work proposes a pulse generator with the characteristics of UWB, high-amplitude, and bipolar output, which contains a bipolar output circuit combining with the Marx circuit and the pulse narrowing circuit. The operating modes and parameters of the circuit are analyzed and verified by PSPICE. A pulse source prototype is produced for an empirical analysis. The result indicates that the designed circuit can output different pulse signals according to various penetrating requirements. When the output pulse amplitude reaches 300 V, the pulsewidth is 2513 ps. Compared with traditional ground-penetrating pulse generators, the pulse generator developed in this work possesses higher pulse amplitude, which can adapt to different detection requirements. Furthermore, it also has a wide range of application prospects in other areas requiring high-precision pulse signals.
摘要：
This paper proposed an input-parallel and output-series (IPOS) LLC resonant converter for applications with high voltage gain and low ripple, which considers the sharing of submodule output voltages. The resonant converter proposed has an integrated magnetics, which improves the utilization of the core. The reason is because magnetic fluxes can be superimposed or cancelled each other when the resonant currents are interleaved. Moreover, the influence of parameter mismatch in the resonant tank on voltage and current sharing in IPOS-LLC was analyzed based on the passive impedance theory. The results show that, by selecting smaller quality factors and using N-connections in high-voltage applications, the sharing of output voltage among modules can be well reflected, despite tolerances of the resonance parameters. Meanwhile, the voltage stress distribution of the rectifier diodes in each submodule is optimized, which improves the reliability of the circuit. By using the aforementioned conclusions, a prototype with 90 kHz, 40 V/4.8 kV, and 1.15 kW is established. The measured output voltage mismatch of 3.1% and voltage ripple rate of 0.16% at 3.7 nF output capacitance proves the effectiveness and correctness of the proposed resonant converter design.
摘要：
A bidirectional pulse power supply with continuously adjustable forward parameters 8 V/20 A and reverse parameters 20 V/50 A was designed using DSP (Digital Signal Processor), and the bidirectional pulse power supply was used to test copper plating on printed circuit boards with filled via holes. The effects of frequencies, pulse width ratios of forward and reverse currents, and current densities on the copper plating effect were investigated by the single variable method and were compared with DC copper plating. The experimental results showed that compared with DC power supply, the bidirectional pulse power supply had a better effect and a faster speed on via-filling copper plating, and can also reduce the use of additives, which is in line with green development. The parameters of the pulse affected the plating effect to varying degrees. In this solution system, the optimal parameters for bidirectional pulse plating are frequency 1 kHz, forward pulse current density 4 ASD (Ampere per Square Decimeter) with 50% duty cycle, and reverse pulse current density 16 ASD with 2.5% duty cycle.
摘要：
With the wide application of pulsed power technology in tumor ablation, sewage treatment, and other related fields, researchers have found that bipolar electrical pulses are more effective than unipolar electrical pulses. In this article, a new bipolar pulse generator is proposed, which combines the features of boost circuit and Marx circuit to significantly improve the boost ratio of output pulse and the tunability of pulse peak. In order to improve the load regulation rate and peak stability of bipolar pulse power supply, a bipolar pulse power supply based on peak closed-loop control method is designed in this article. The high-voltage pulse is attenuated, and its peak is sampled by the pulse peak sampling circuit, and the pulse peak voltage is fed back to the DSP controller for comparison with the set peak value, and the proportional integral differential (PID) adjustment is performed according to the voltage deviation, and the boost ratio of the pulse generator is changed to realize the constant peak output of the bipolar pulse. In order to verify the feasibility of the proposed bipolar pulse generator with peak closed-loop control scheme, simulation and experimental studies of the bipolar pulse power supply with five-stage peak closed-loop control were conducted. The results show that the output repetition frequency of 5 kHz, pulsewidth of 5– $10~\mu \text{s}$ , and peak pulse value within ±2.0 kV can be stabilized when the input voltage is 100 V.
作者机构：
[Zhijian Liu; Wenguang Chen; Li Peng; Liang Zheng] School of Electrical Engineering, University of South China, Hengyang, China
会议名称：
2023 3rd International Conference on Energy, Power and Electrical Engineering (EPEE)
会议时间：
15 September 2023
会议地点：
Wuhan, China
会议论文集名称：
2023 3rd International Conference on Energy, Power and Electrical Engineering (EPEE)
关键词：
screen-grid power supply;resonant converter;arc energy;voltage ripple
摘要：
In this paper, a three-phase LCC resonant converter is designed to meet the operating requirements of a high boost ratio, wide output range, and stable output power for the screen-grid power supply of an ion thruster with a single-stage structure. Since the converter operates in three-phase interleaved mode, the output voltage ripples cancel each other, reducing the output capacitor capacity greatly and suppressing the arc energy of the inter-screen grid fault discharge fundamentally. In addition, a wide range of voltage outputs can be realized by controlling the converter to operate in three different modes: half-bridge, full-bridge, and three-phase interleaved. Finally, the experimental prototype accomplished the design specifications of 1kV/500W, efficiency of 92%, voltage ripple of 0.6%, and 8.5mJ energy storage in the output capacitor.
会议名称：
9th International Forum on Electrical Engineering and Automation (IFEEA)
会议时间：
NOV 04-06, 2022
会议地点：
ELECTR NETWORK
会议主办单位：
[Wang, Shoutao;Chen, Wenguang;Liu, Zhijian;Wei, Caiyi;Peng, Yuanyuan] Univ South China, Sch Elect Engn, Hengyang, Peoples R China.
关键词：
Printed circuit board;Bidirectional pulse power supply;Forward and reverse pulse duty cycle ratio;Current density;Frequency
摘要：
Printed circuit boards are the most important basic electronic components in the electronics industry, and copper plating technology is widely used in the field of printed circuit board manufacturing. Pulse plating is more efficient and environmentally friendly than DC plating, and the plating layer of pulse plating is more uniform and detailed. The effect of bidirectional pulse power supply parameters on the copper plating effect of printed circuit board surface was investigated by using a self-developed bidirectional pulse power supply. The experimental results show that the frequency, forward and reverse pulse duty cycle and current density of the bidirectional pulse power supply have certain effects on the copper plating effect.
作者：
Wenxiu Wu;Chengdong Gui;Puqiong Yang;Wenguang Chen;Yanliang Tan
作者机构：
[Yanliang Tan] Hunan Provincial Key Laboratory of Intelligent Information Processing and Application, Hengyang, China;[Wenxiu Wu; Chengdong Gui; Puqiong Yang; Wenguang Chen] School of Electrical Engineering, University of South China, Hengyang, China
会议名称：
2021 IEEE 4th International Electrical and Energy Conference (CIEEC)
会议时间：
28 May 2021
会议地点：
Wuhan, China
会议论文集名称：
2021 IEEE 4th International Electrical and Energy Conference (CIEEC)
关键词：
Electronic control cooling system;Non-linear control;Energy consumption optimization;Fuzzy control
摘要：
A simplified mathematical model of the vehicle engine electronic control cooling system is established by using the lumped parameter method, and non-linear control strategy and fuzzy control strategy are introduced to simulate the cooling system. Taking the optimal coolant temperature of the vehicle engine outlet as the research objective, non-linear controller, fuzzy controller and self-adjusting fuzzy controller are designed to control the engine coolant temperature and to study the energy consumption optimization of the cooling system. Experiments show that compared with non-linear control, self-adjusting fuzzy control, and fuzzy control strategy, When the engine is in the maximum heat load and the electronic valve is fully open, the energy consumption of the cooling system can be reduced by 33% by using self-adjusting fuzzy control strategy.
期刊：
Review of Scientific Instruments,2021年92(1):014706-1-014706-6 ISSN：0034-6748
通讯作者：
Chen, Wenguang
作者机构：
[Rao, Yihua] Univ South China, Sch Math & Phys, Hengyang 421001, Peoples R China.;[Du, Jia; Chen, Wenguang] Univ South China, Sch Elect Engn, Hengyang 421001, Peoples R China.
通讯机构：
[Chen, Wenguang] U;Univ South China, Sch Elect Engn, Hengyang 421001, Peoples R China.
摘要：
A solid-state suppress grid power supply (SGPS) is developed to be applied to the 5 MW level neutral beam injection (NBI) on HL-2M Tokamak. The power supply consists of ten modules in series, with an index of 560 V/40 A. Each of the modules is composed of an isolated transformer, rectifier, filter tank, insulated gate bipolar transistor switch, gate-drive circuit, free-wheeling diode, and so forth. An embedded system STM32F103 is used for controlling and protecting the SGPS. Meanwhile, the transient output capacity of the SGPS is tested. The effect of the output voltage of the SGPS on the extracted beam current is studied. The experimental results show that there is a turning point in the relationship between the suppress voltage and the extracted beam current. When the rate of the absolute value of the suppress voltage and the gradient voltage is more than 2.5%, the efficiency of the extracted beam of the ion source can be improved. Compared with the previous types of equipment of the NBI system, the extracted beam success rate of the new SGPS increased by more than 20%. The SGPS meets the requirements of the NBI system.
摘要：
To monitor the operating conditions of power transformers in real-time and predict the loosening faults of the transformers, the finite element simulation software is used to model the transformer, to simulate the vibration of the transformer core under different compressive stresses during its operation, and to analyze the vibration signal in this paper. Firstly, the transformer is modeled, and the electromagnetic field distribution of the transformer is solved through field-circuit coupling. Then, the force condition and vibration displacement distribution of the transformer are solved through the coupling of the electromagnetic field and structural force field. Finally, the simulation results of normal and fault conditions are compared, and the vibration characteristics of fault conditions are obtained. The experimental results show that the high order harmonic components in the vibration acceleration spectrogram increase significantly when the transformer core has a loosening fault, among which the 600Hz harmonic component increases the most.
作者机构：
[Yi-Hua Rao] School of Mathematics and Physics, University of South China, Hengyang, China;[Wen-Guang Chen; Jia Du; Xiao-Xu Deng] School of Electrical Engineering, University of South China, Hengyang, China
会议名称：
2020 4th International Conference on HVDC (HVDC)
会议时间：
06 November 2020
会议地点：
Xi'an, China
会议论文集名称：
2020 4th International Conference on HVDC (HVDC)
关键词：
high voltage pulse discharge;uranium;electric field;mineral composition;dielectric constant
摘要：
Uranium is the most basic material for the operation of nuclear power plants. Research on methods for extracting uranium efficiently and pollution-free is one of the hot issues in nuclear energy development. In nature, uranium is abundant in hard rock, but it is often wraped by volcanic rock. The traditional method of extracting uranium mainly uses heap leaching or in-situ leaching, but acid solution cannot enter the hard rock to extract uranium. In this paper, a highvoltage pulse power supply is designed with hydrogen thyristor as the switching device. The maximum output amplitude is 30 kV, the frequency is 1 Hz-1 kHz, and the pulse width is adjustable between 0-5μs. The influence of parameters such as the composition of uranium ore, the particle size of the ore, and the distance of the discharge electrode on the characteristics of the discharge electric field was simulated by COMSOL Multiphysics software, and the influence of the electric field intensity and its distribution relationship were obtained. Finally, the designed high-voltage pulsed power supply is applied to discharge the underwater volcanic rock. The results show that the discharge cannot significantly break the ore, but it can significantly reduce the mechanical strength of the ore and increase the porosity. The overall metal content in the composition of uranium ore determines the crushing effect mainly, and the electrode distance and particle size also affect the breakdown time and breakdown voltage. This method can also provide reference for other similar mineral processing.
会议名称：
3rd IEEE International Electrical and Energy Conference (CIEEC)
会议时间：
SEP 07-09, 2019
会议地点：
Beijing, PEOPLES R CHINA
会议主办单位：
[Gui, Chengdong;Chen, Wenguang;Du, Jia;Hu, Wei] Univ South China, Sch Elect Engn, Hengyang 421000, Hunan, Peoples R China.
关键词：
Cooling system;Mathematical model;Coolant Temperature;Energy consumption optimization;Fuzzy control
摘要：
From the perspective of thermodynamics, based on the structural characteristics of the vehicle engine permanent magnet synchronous motor (PMSM) driving cooling system and the principle of heat dissipation, a simplified mathematical model of the cooling system is established. Taking the optimal coolant temperature and system energy consumption optimization at the engine as the research goal, the fuzzy control algorithm is adopted to adjust the speed of the motor-driven cooling fan, and a nonlinear control strategy is introduced for a comparative study. The energy consumption of the cooling system is analyzed and optimized to ensure optimum engine outlet coolant temperature. The results show that the fuzzy control strategy has a fast response speed, which can control the coolant temperature at engine outlet within 90 +/- 0.25 degrees C, and can reduce the energy consumption of the entire cooling system.
