scholarly journals Improved Model Analysis and Current-Loop Design for Marine Controlled Source Electromagnetic Transmitter

2017 ◽  
Vol 141 ◽  
pp. 557-564
Author(s):  
Jianzhi Ding ◽  
Yiming Zhang
Keyword(s):  
Model Analysis ◽  
Current Loop ◽  
Controlled Source ◽  
Loop Design ◽  
Electromagnetic Transmitter ◽  
Improved Model

Research on Controlling Method of High-Power Electromagnetic Transmitter Power Supply

2013 ◽  
Vol 339 ◽  
pp. 614-620
Author(s):  
Fei Yu
Keyword(s):  
High Power ◽  
Power Supply ◽  
Control Method ◽  
Current Loop ◽  
Complex Environments ◽  
Loop Control ◽  
Transmitter Power ◽  
Current Sharing ◽  
Current Sharing Control ◽  
Electromagnetic Transmitter

High-power electromagnetic transmitter power supply is an important part of deep geophysical exploration equipment, especially in complex environments, where how to control the high accuracy and stable output of the power supply as well as the redundancy safety of the system become the key issue in its designing. A triple-loop control including inner current loop, outer voltage loop and load current forward feedback and a digitalized voltage/current sharing control method are proposed for the realization of the rapid, stable and highly accurate output of the system. System simulation and field geological exploration experiments demonstrate the effectiveness of the control method which could ensure both the systems excellent stability and the outputs accuracy.

scholarly journals Modeling and Control System Design of Marine Controlled-Source Electromagnetic Detection Transmitter

2015 ◽  
Vol 9 (1) ◽  
pp. 571-578
Author(s):  
Tao Haijun ◽  
Zhang Yiming ◽  
Ren Xiguo
Keyword(s):  
Electromagnetic Wave ◽  
Mineral Resources ◽  
Current Mode ◽  
Response Speed ◽  
Equivalent Model ◽  
Current Loop ◽  
Large Power ◽  
Loop Control ◽  
Modeling And Control ◽  
Controlled Source

Marine electromagnetic transmitter transmits large power variable frequency electromagnetic wave to the seabed so as to obtain the submarine structure and mineral resources. The mathematical model of controlled source circuit needs to be established to realize closed loop control for increasing control precision and output transient performance of the electromagnetic wave. The operation process of controlled circuit is analyzed in continuous current mode, two equivalent switching states of controlled source circuit are obtained through the analysis of the different states of the switch in a switching period. A small signal equivalent model of the system is established using small ripple approximation. For high output voltage fluctuation problem in single loop control, double loop control strategy of voltage loop and current loop is designed. The simulation and experimental results show that, the system has the advantages of fast transient response speed and good regulation performance.

scholarly journals Improved Model Predictive Current Control of Single-Phase Five-Level PWM Rectifier

Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2214
Author(s):  
Yifeng Zhu ◽  
Hao Yue ◽  
Hailong Zhao ◽  
Huichun Xu
Keyword(s):  
Model Predictive Control ◽  
Objective Function ◽  
Predictive Control ◽  
Single Phase ◽  
Current Control ◽  
Current Loop ◽  
Switching Frequency ◽  
Two Phase ◽  
Small Current ◽  
Improved Model

In this paper, a single-phase five-level rectifier with coupled inductors is studied. First, a discrete mathematical model of a single-phase five-level rectifier is created in two-phase(αβ). A traditional single vector finite control set model predictive control (FCS-MPC) algorithm is improved to overcome the problems of a varying switching frequency, the large amount of time needed for calculation, and the inaccurate setpoint of current loop tracking. Then, the objective function of the system is established, and a simple objective function is used instead of an iterative optimization of the traditional FCS-MPC algorithm. At the same time, to eliminate the delay error and to reduce harmonic distortion, deadbeat control technology is introduced. Finally, the simulation and experimental results show that the improved model predictive current control algorithm not only retains the fast response of traditional model predictive control, but also has the advantages of fixed switching frequency, small calculation time, and small current steady-state error.

Resistivity imaging of controlled‐source audiofrequency magnetotelluric data

Geophysics ◽  
1992 ◽  
Vol 57 (7) ◽  
pp. 952-955 ◽  
Author(s):  
Yutaka Sasaki ◽  
Yoshihiro Yoneda ◽  
Koichi Matsuo
Keyword(s):  
Current Loop ◽  
Magnetotelluric Data ◽  
Model Inversion ◽  
Controlled Source ◽  
Smooth Model ◽  
Resistivity Model ◽  
Em Method ◽  
Survey Results ◽  
Plane Wave Approximation ◽  
A Current

The controlled‐source audiofrequency magnetotelluric (CSAMT) method is an electromagnetic (EM) method where a transmitter (a grounded electric bipole or a current loop) is placed far away from the receiver sites. If the transmitter is located at distances greater than 3–5 skin depths, the plane-wave approximation is valid and the techniques used for (natural source) MT interpretation can be applied (Goldstein and Strangway, 1975; Sandberg and Hohmann, 1982). The CSAMT method can be employed in a detailed survey by closely spacing a number of receiver sites along a traverse. The borehole CSAMT technique is proposed in West and Ward (1988) to enhance the ability of the surface CSAMT method to detect subsurface inhomogeneities. In these cases, two‐dimensional (2-D) smooth‐model inversion (Rodi et al., 1984; Sasaki, 1989; deGroot‐Hedlin and Constable, 1990) would be particularly useful for deriving a resistivity model from the far‐field data and for presenting the survey results in the form of an image.

Agricultural Nonpoint Source Pollution Model Analysis and Application

2012 ◽  
Vol 178-181 ◽  
pp. 926-929
Author(s):  
Qing Yang ◽  
Sheng Nan Sun ◽  
Zheng Hai Jiang ◽  
Li Xian Ying ◽  
Zhe Jun Liu
Keyword(s):  
Point Source ◽  
Best Management Practices ◽  
Management Practices ◽  
Swat Model ◽  
Model Analysis ◽  
Point Source Pollution ◽  
Mechanism Model ◽  
3S Technology ◽  
Improved Model ◽  
Non Point Source Pollution

With the point source pollution was effectively treated, non-point source pollution, especially the agricultural non-point source pollution (ANPSP), is becoming the main problem in environment. The research is focused on the model analysis and application, which could be scientifically distinguish and effectually control ANPSP. Four kinds of models were introduced here with the development of non-point source pollution, as experience statistical model, mechanism model, function model, improved model by 3S technology and the uncertain analyze. Among these models, HSPF and SWAT model were successfully applied in best management practices (BMP) for ANPSP control. In the future, our country should base on the introduction of the foreign mature techniques, which combine the 3S technology and the uncertain improved model, then enhance the autonomous model research and build the basic database.

scholarly journals A comprehensive data quality evaluation method for the current of marine controlled-source electromagnetic transmitter based on Analytic Hierarchy Process

2019 ◽  
Author(s):  
Rui Yang ◽  
Meng Wang ◽  
Gongxiang Wang ◽  
Ming Deng ◽  
Jianen Jing ◽  
...  
Keyword(s):  
Electromagnetic Wave ◽  
Analytic Hierarchy Process ◽  
Quality Evaluation ◽  
Evaluation Method ◽  
Current Data ◽  
Analytic Hierarchy ◽  
Controlled Source ◽  
Electromagnetic Transmitter ◽  
Hierarchy Process

Abstract. Marine controlled-source electromagnetic method has more and more applications in ocean resources exploration. Electromagnetic transmitter sends electromagnetic wave to the underground, the receiver located on the seafloor receives the electromagnetic wave which carries the information of the geosphere. And the underground structure is obtained by inversion calculation. Data quality of electromagnetic transmitter and seafloor receivers is the most important part of this method. The quality level of transmitting current directly affects the signal-to-noise ratio (SNR) of the electromagnetic field data, as received by a multi-component electromagnetic receiver from the seabed. Although the transmitting current stability is sufficient under normal circumstances, the SNR of the received signal can change owing to factors such as outside noise. In some emergency cases such as instrument failure or a sudden increase in electromagnetic interference that we are not aware of, the frequency and properties of the transmitting current may change, such as its size and waveform. The traditional current monitoring and data playback tools fail to detect and evaluate the anomalies well and in a timely manner, which introduces considerable errors in the later data processing procedure. Pertaining to these issues, this paper proposes a comprehensive quality evaluation method for the transmitting current. The proposed algorithm, based on the analytic hierarchy process, is first used to analyse five current stability parameters: current frequency, positive amplitudes, negative amplitudes, discrepancy of ideal waveform, and waveform repetition and then to define the harmonic energy and calculate the quality of transmitting current (QTC) index of the final data to assess the quality of the transmitting current comprehensively. The results of a marine experiment performed in 2016 show that the algorithm can identify abnormal current data and quantitatively evaluate the current conditions. Under normal circumstances, the QTC index is within 2 %. However, after the simulation of anomalous mutations of the various attributes, the QTC index synchronized mutations to more than 4 % and some curvilinear features were observed. These results will provide a positive, significant guide for the evaluation and monitoring of transmitting current data in marine experiments.

scholarly journals Small power ZVS circuits for the marine-controlled source electromagnetic transmitter

2019 ◽  
Vol 2019 (17) ◽  
pp. 4325-4330
Author(s):  
Hongxi Song ◽  
Yiming Zhang ◽  
Junxia Gao ◽  
Yu Zhang
Keyword(s):  
Small Power ◽  
Controlled Source ◽  
Electromagnetic Transmitter
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