scholarly journals Small-Signal Modeling of Marine Electromagnetic Detection Transmitter Controlled-Source Circuit

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Haijun Tao ◽  
Yiming Zhang ◽  
Xiguo Ren
Keyword(s):  
Electromagnetic Waves ◽  
Frequency Conversion ◽  
Input Voltage ◽  
Current Transformer ◽  
Soft Switching ◽  
Small Signal ◽  
Large Power ◽  
Loop Control ◽  
Controlled Source ◽  
Low Efficiency

Marine electromagnetic transmitter transmits electromagnetic waves with large power frequency conversion to the seabed to obtain the submarine structure and mineral resources. However, the current transmitter presents several problems, such as low efficiency, serious heat, and poor adaptability to the load. Soft-switching controlled-source circuit is used to reduce circuit losses. The mathematical model of controlled-source circuit should be established to realize a closed-loop control for increasing the output transient performance of electromagnetic waves. Given that the soft-switching controlled-source circuit has more status and that direct modeling is difficult, small-signal model of soft-switching controlled-source circuit is established based on that of hard-switching controlled-source circuit by analyzing the effect of output filter inductor current transformer leakage inductance and input voltage soft-switching controlled circuit on change in the duty cycle. Finally, experiments verify the accuracy and validity of the model.

EXPERIMENTAL RESULTS FOR THE SMALL-SIGNAL STUDY OF THE PWM BOOST DC–DC CONVERTER WITH AN INTEGRAL-LEAD CONTROLLER

1995 ◽  
Vol 05 (04) ◽  
pp. 747-755 ◽  
Author(s):  
MARIAN K. KAZIMIERCZUK ◽  
ROBERT C. CRAVENS, II
Keyword(s):  
Closed Loop ◽  
Transfer Functions ◽  
Low Frequency ◽  
Input Voltage ◽  
Open Loop ◽  
Small Signal ◽  
Loop Control ◽  
Pulse Width Modulated ◽  
Bode Plots ◽  
Step Responses

An experimental verification of previously derived small-signal low-frequency open- and closed-loop characteristics and step responses of a voltage-mode-controlled pulse-width-modulated (PWM) boost DC–DC converter is presented. The Bode plots of the voltage transfer function of the control circuit, the converter and the PWM modulator, the open-loop control-to-output and input-to-output transfer functions, the loop gain, and the closed-loop control-to-output and input-to-output transfer functions are measured. The step responses to the changes in the input voltage, the duty cycle, and the reference voltage are measured. The theoretical results were in good agreement with the measured results. The small-signal model of the converter is experimentally verified.

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 Three-Level DC-DC Controlled-Source Circuit of Marine Electromagnetic Detection Transmitter

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Haijun Tao ◽  
Guopeng Zhang ◽  
Zheng Zheng
Keyword(s):  
High Power ◽  
Electromagnetic Waves ◽  
High Efficiency ◽  
Mineral Resources ◽  
Soft Switching ◽  
High Voltage Power Supply ◽  
Controlled Source ◽  
Detection Depth ◽  
In Series ◽  
Electromagnetic Transmitter

Nowadays, marine electromagnetic method is a geophysical method which can effectively explore natural gas hydrate (NGH) resources. This method acquires seafloor structure and distribution laws of mineral resources by transmitting high-power electromagnetic waves to the seafloor, and its detection depth relies on the intensity of transmitted electromagnetic waves. At present, marine electromagnetic transmitter is not proper for transmission of high-power electromagnetic waves, and therefore, a novel controlled-source circuit of soft switching three-level marine electromagnetic transmitter is proposed in this paper, one step-down winding is added at the secondary side of high-frequency transformer in series connection with a linear inductor, asymmetric phase-shift PWM control is used, and soft switching of controlled-source circuit within the overall power range is realized. A detailed analysis of the operation process and circuit characteristics is given, and finally, a prototype is designed. Experimental results indicate that this circuit is of wide ZVS range and high efficiency, and it meets requirements for deep-sea detection of high-voltage power supply transmitter.

scholarly journals Analysis of a Wide Voltage Hybrid Soft Switching Converter

Electronics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 473 ◽  
Author(s):  
Bor-Ren Lin ◽  
Yen-Chun Liu
Keyword(s):  
Power Conversion ◽  
Input Voltage ◽  
Soft Switching ◽  
Resonant Converter ◽  
Solar Pv ◽  
Load Range ◽  
Pwm Converter ◽  
Load Voltage ◽  
Zero Voltage Switching ◽  
Circulating Current

A hybrid PWM converter is proposed and investigated to realize the benefits of wide zero-voltage switching (ZVS) operation, wide voltage input operation, and low circulating current for direct current (DC) wind power conversion and solar PV power conversion applications. Compared to the drawbacks of high freewheeling current and hard switching operation of active devices at the lagging-leg of conventional full bridge PWM converter, a three-leg PWM converter is studied to have wide input-voltage operation (120–600 V). For low input-voltage condition (120–270 V), two-leg full bridge converter with lower transformer turns ratio is activated to control load voltage. For high input-voltage case (270–600 V), PWM converter with higher transformer turns ratio is operated to regulate load voltage. The LLC resonant converter is connecting to the lagging-leg switches in order to achieve wide load range of soft switching turn-on operation. The high conduction losses at the freewheeling state on conventional full bridge converter are overcome by connecting the output voltage of resonant converter to the output rectified terminal of full bridge converter. Hence, a 5:1 (600–120 V) hybrid converter is realized to have less circulating current loss, wide input-voltage operation and wide soft switching characteristics. An 800 W prototype is set up and tested to validate the converter effectiveness.

scholarly journals A Small-Divergence-Angle Orbital Angular Momentum Metasurface Antenna

Research ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Jianchun Xu ◽  
Ke Bi ◽  
Ru Zhang ◽  
Yanan Hao ◽  
Chuwen Lan ◽  
...  
Keyword(s):  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Electromagnetic Waves ◽  
Divergence Angle ◽  
Compact Structure ◽  
Phase Gradient ◽  
Practical Applications ◽  
Circular Arrangement ◽  
Low Efficiency ◽  
Theoretical Analyses

Electromagnetic waves carrying an orbital angular momentum (OAM) are of great interest. However, most OAM antennas present disadvantages such as a complicated structure, low efficiency, and large divergence angle, which prevents their practical applications. So far, there are few papers and research focuses on the problem of the divergence angle. Herein, a metasurface antenna is proposed to obtain the OAM beams with a small divergence angle. The circular arrangement and phase gradient were used to simplify the structure of the metasurface and obtain the small divergence angle, respectively. The proposed metasurface antenna presents a high transmission coefficient and effectively decreases the divergence angle of the OAM beam. All the theoretical analyses and derivation calculations were validated by both simulations and experiments. This compact structure paves the way to generate OAM beams with a small divergence angle.

Self-learning current optimizing control for conventional stepping motor drive technique based on step pulses

2021 ◽  
pp. 014233122110464
Author(s):  
Jasper De Viaene ◽  
David Ceulemans ◽  
Stijn Derammelaere ◽  
Kurt Stockman
Keyword(s):  
Electrical Parameter ◽  
Open Loop ◽  
Motor Drive ◽  
Stepping Motor ◽  
Loop Control ◽  
Unique Character ◽  
Hybrid Stepping Motor ◽  
Low Efficiency ◽  
Optimizing Control ◽  
Self Learning

The essential advantage of the conventional stepping motor drive technique bases on step command pulses is the ability of open-loop positioning. By ruling out the cost of a position sensor, stepping motors are preferred in low power positioning applications. However, machine developers also want to obtain high dynamics with these small and cheap stepping motors. For that reason, stepping motors are used at its limits as much as possible. A drawback of the open-loop control is the continuous risk of missing a step due to overload. Due to this uncertainty, robustness is a major issue in stepping motor applications. Until today, to reduce the possibility of step loss, the motor is typically driven at maximum current level or is over-dimensioned with results in low-efficiency. Therefore in this paper, a self-learning [Formula: see text]-controller optimizing the current is presented. Moreover, to allow broad industrial applicability, this technique is computationally simple, needs no mechanical or electrical parameter knowledge and take into account the unique character of stepping motors and their conventional drive technique based on step command pulses. The proposed algorithm is validated through measurements on a hybrid stepping motor.

Sign in / Sign up

Export Citation Format

Share Document