Dual‑mode control strategy based on DC‑bus voltage for dual‑active bridge converter in marine electromagnetic transmitter system

Haijun Tao,Changshun Du,Guopeng Zhang,Zheng Zheng 전력전자학회 2022 JOURNAL OF POWER ELECTRONICS Vol.22 No.2

The marine electromagnetic detection method is the main method for the exploration of marine oil and gas resources. At present, the controlled source circuit of the electromagnetic transmitter is a unidirectional flow of electric energy. When the emission electrodes release the stored energy, the energy cannot be fed back, resulting in an increased DC bus and switch device voltages. The stress increases and the filter capacitors and switch devices are burned, which cannot guarantee the long-term reliable operation of the underwater devices body in the deep sea. A dual-active bridge converter is presented for the controlled source circuit of the electromagnetic transmitter. First, the topology, operating principle, and soft-switching constraints are introduced in detail. Then, a dual-mode control strategy is designed. The inductor current stress optimization control is adopted to ensure a steady-state operation, and the univariate extended phase-shifting sliding mode control is applied to achieve fast energy feedback of the inductive load. Simulation and experimental results show that the proposed circuit significantly reduces the bus voltage effect and switch device voltage stress, improves the efficiency and dynamic performance of the system, and satisfies the needs of deep-sea oil and gas resource exploration.

Cascaded controllable source circuit and control of electromagnetic transmitters for deep sea exploration

Haijun Tao,Naitong Yang,Hongyi Wang 전력전자학회 2024 JOURNAL OF POWER ELECTRONICS Vol.24 No.2

The electromagnetic detection method is the main method of marine oil and gas resource exploration, and the marine electromagnetic transmitter is the key equipment of marine electromagnetic detection systems. At present, the power factor of the controllable source circuit of the electromagnetic transmitter is low, energy cannot be fed back, and the capacitance of the filter capacitor is large, which results in a large volume of the electromagnetic transmitter and high maintenance costs. Thus, a cascaded H-bridge controllable source circuit combined with active power decoupling technology is introduced in this paper. First, the topological structure and working principle of the controllable source circuit of the electromagnetic transmitter are analyzed, and an improvement plan is proposed for the existing problems of the controllable source circuit. Second, the working principle of the improved controllable source circuit is analyzed, and the advantages of the improved scheme are expounded. Then a control strategy based on linear active disturbance rejection control (ADRC) is proposed, and a linear ADRC controller is designed. Simulation results show that the improved controllable source circuit reduces thecapacitance value, improves the power factor, reduces the volume of the underwater towing body, and reduces the maintenance cost of the system. The proposed control strategy makes the DC voltage have better anti-disturbance performance, and improves the reliability of the electromagnetic transmitter in deep sea exploration.

Hot Deformation and Workability of a CrCoNi Medium Entropy Alloy

Haijun Wang,Zhitong Hu,Junsheng Cao,Shuai Zhang,Tao Cheng,Qingyan Wang 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.2

Hot compression behaviors of CrCoNi medium entropy alloy are were performed on the Gleeble-3800 thermal simulator inthe strain rate range from 0.01 to 10 s−1 and the temperature range from 800 to 1100 °C. According to the true stress-truestrain curves, the true stress decreases with the decreasing of strain rate and the increasing of deformation temperature. Theexperimental parameters were fitted, and a modified model based on Arrhenius hyperbolic sine was established. Amongthem, material constants such as, n, A, and Q are functions of strain. Meanwhile, the processing map of CrCoNi mediumentropy alloy under different strain conditions are established. Importantly, the optimal domain of apparent flow stabilitycan be determined as the deformation temperature from 900 to 1100 °C and the strain rate from 0.01 to 10 s−1. The resultsindicate that the stability domain of the CrCoN medium entropy alloy has a wider range, and the strain has little effect onits processing performance.

Dynamic Coalition Formation Based on Multi-sided Negotiation

Lin Xiang,Haijun Tao 보안공학연구지원센터 2015 International Journal of Database Theory and Appli Vol.8 No.1

The coalition formation is an important aspect of multi-agent negotiation and cooperation. Based on the Bilateral Shapley-Value, a multi-sided eigenvalue is presented by using the reference of n-person stochastic cooperative game. It is obvious when multi-sided eigenvalue have superadditivity, rational agents will combine to one coalition. A dynamic coalition formation algorithm is constructed based on the eigenvalue. Procedures of multi-sided negotiation, agent’s negotiation and coalition condensing are introduced in detail. In the end, the complexity, validity, coalition stability and parameter’s function of the algorithm is given. According to these, the correctness of the algorithm is proven.

A Method for The Evaluating Performance of High Power Electromagnetic Transmitter

Xiguo Ren,Yiming Zhang,Haijun Tao,Xuezheng Zhu 보안공학연구지원센터 2016 International Journal of u- and e- Service, Scienc Vol.9 No.9

In recent years, the Earth's resources have the obvious contradiction between supply and demand. Electromagnetic has become the most effective means for prospecting geological structure. In the electromagnetic method, the transmission frequency has a significant impact on the reception and subsequent analysis. Therefore, the distribution and stability of the actual transmission frequency is an extremely important factor in judging for the transmitter. This paper presents an assessment method of the transmitting the performance parameters for the high-power electromagnetic transmitter. This method can intuitively observe the actual transmission frequency by the position machine when the transmitter is working. And the frequency distribution and stability could be got by Matlab. After a large number of comparative field trials, this method is verified which could quickly and efficiently get the frequency distribution and stability of the actual transmitting. This method could provide a basis for future inversion calculation and have a guiding role for the transmitter optimization.

A Carrier Communication Channel Modeling Of Marine Electromagnetic Exploration System Based On Multi Conductor Transmission Line Theory

Xiguo Ren,Yiming Zhang,Haijun Tao,Zhihui Zeng,Jianzhi Ding 보안공학연구지원센터 2016 International Journal of Future Generation Communi Vol.9 No.10

Subsea communication system is a key component of marine electromagnetic exploration system. In subsea communication system, only the power line channel model is fully studied, it could help to achieve high-speed and reliable power line carrier communication. In this paper, a channel model is established by using the theory of multi conductor transmission. The single Pi structure, double Pi structure and T structure cable model have been simulated through the Spice. The accuracy of single Pi structure model was verified by measurement and simulation. It provides a guiding role for the whole communication system.

Fundamental impedance‑based digital synchronous rectification scheme for bidirectional CLLC resonant converters

Guopeng Zhang,Xindi Sun,Hao Wang,Yonghui Liu,Haijun Tao,Lulu Huang 전력전자학회 2024 JOURNAL OF POWER ELECTRONICS Vol.24 No.1

Synchronous rectification (SR) is an effective way to improve the efficiency of CLLC resonant converters. The soft switching of SR is affected by the parasitic capacitance and the zero-crossing point of the current of the secondary inductance. Therefore, based on uncontrolled rectification on the secondary of the converter, the effective range of soft switching for SR under different operating modes is analyzed. A fundamental impedance model is established to obtain the discharge time of the parasitic capacitance and the zero-crossing point of the current of the secondary in the upper resonant frequency mode. The relationship between the SR signals and primary driving signals in different operating modes is summarized, which can improve the operating range of the SR while ensuring soft-switching. This in turn, ensures the operating efficiency of the converter. The calculation method of the turn-ON and turn-OFF times of the SR in different modes is improved. In addition, the proposed SR method can be used in bidirectional CLLC resonant converters that do not have SR functionality. To accomplish this, only the control program needs to be updated. Experimental results on a 200 V 500 W prototype are given to verify the effectiveness of the SR method.

Calculation of Leakage Inductance of Integrated Magnetic Transformer with Separated Secondary Winding Used in ZVS PSFB Converter

Tian Jiashen,Zhang Yiming,Ren Xiguo,Wang Xuhong,Tao Haijun 한국자기학회 2016 Journal of Magnetics Vol.21 No.4

A novel zero voltage switching (ZVS) phase shift full bridge (PSFB) converter used in geophysical exploration is proposed in this paper. To extend the ZVS ranges and increase power density of the converter, external inductor acting as leakage inductance is applied and integrated into the integrated magnetic (IM) transformer with separated secondary winding. Moreover, the loss of ZVS PSFB converter is also decreased. Besides, the analysis and accurate prediction methodology of the leakage inductance of the IM transformer are proposed, which are based on magnetic energy and Lebedev. Finally, to verify the accuracy of analysis and methodology, the experimental and finite element analysis (FEA) results of IM transformer and 40 kW converter prototypes are given.

Smart and versatile biomaterials for cutaneous wound healing

Minxiong Li,Wenzheng Xia,Yi Min Khoong,Lujia Huang,Xin Huang,Hsin Liang,Yun Zhao,Jiayi Mao,Haijun Yu,Tao Zan 한국생체재료학회 2023 생체재료학회지 Vol.27 No.00

The global increase of cutaneous wounds imposes huge health and financial burdens on patients and society. Despite improved wound healing outcomes, conventional wound dressings are far from ideal, owing to the complex healing process. Smart wound dressings, which are sensitive to or interact with changes in wound condition or environment, have been proposed as appealing therapeutic platforms to effectively facilitate wound healing. In this review, the wound healing processes and features of existing biomaterials are firstly introduced, followed by summarizing the mechanisms of smart responsive materials. Afterwards, recent advances and designs in smart and versatile materials of extensive applications for cutaneous wound healing were submarined. Finally, clinical progresses, challenges and future perspectives of the smart wound dressing are discussed. Overall, by mapping the composition and intrinsic structure of smart responsive materials to their individual needs of cutaneous wounds, with particular attention to the responsive mechanisms, this review is promising to advance further progress in designing smart responsive materials for wounds and drive clinical translation.