scholarly journals Research on performance optimization and mechanism of electrochemical water softening applied by pulse power supply

2021 ◽  
Author(s):  
Zhonghao Wang ◽  
Wei Lin ◽  
Wei Wang ◽  
Zhangwei Wang ◽  
Jimin Li ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Power Supply ◽  
Performance Optimization ◽  
High Speed ◽  
Unit Area ◽  
Cooling Water ◽  
Longitudinal Direction ◽  
Growth Direction ◽  
Water Softening ◽  
Electrode Plate

Abstract In order to promote the application of electrochemical water softening technology in industrial circulating cooling water systems, electric field type, cathode structure and solution residence time are selected for optimization analysis of electrochemical water softening device. The experimental results show that the water softening performance per unit area of mesh cathode is better than that of plate cathode. In addition, the softening amount per unit area of the mesh cathode can be further increased when the high-frequency (HF) power supply is applied. When the HF power supply is applied, the softening amount per unit area is 158.58 g/m2·h−1 more than that the direct current power supply is applied. In order to explore the growth mechanism of calcium carbonate, micro-analysis technology and high-speed bubble photography technology are used. The results show that the bubbles escape along the longitudinal direction of the electrode plate, and the main growth direction of calcium carbonate growth is consistent with the escape direction of the bubble, that is, the bubbles grow along the longitudinal direction of the electrode plate. The special structure of the diamond-shaped mesh cathode facilitates the growth of calcium carbonate crystals.

Ensuring electrical safety of power supply systems of electrified AC railways for highspeed lines

2018 ◽  
Vol 77 (6) ◽  
pp. 337-346 ◽  
Author(s):  
A. B. Kosarev ◽  
A. V. Barch ◽  
E. N. Rozenberg
Keyword(s):  
Power Supply ◽  
High Speed ◽  
Structural Features ◽  
Electrical Safety ◽  
Safe Operation ◽  
Ballastless Track ◽  
Conventional Structure ◽  
Artificial Earth ◽  
Earth Connection ◽  
Supply Systems

Abstract. High-speed railways are fast-growing and promising type of traffic. In Russia development of high-speed railway service is associated with the solution of a number of problems, including infrastructure. Authors propose to use earth connection of the railway catenary with the help of an artificial earthing switch on currently designed high-speed line Moscow—Kazan for 2×25 kV power supply system. Taking into account requirements for electrical safety conditions for maintenance of the track and earthed catenary supports, paper justifies method for calculating allowable voltages of rail—earth points and supports of catenary. Methods takes into account structural features of ballastless track superstructure used for high-speed lines. It is estimated that the voltages admissible under the electrical safety conditions are random in nature and distributed logarithmically normal. When calculating probability of safe operation, one should take into account random nature of both permissible stresses and those actually occurring on the track. It is estimated that the probability of safe operation in traction networks of sections with ballastless track superstructure does not exceed a similar value in electrified sections with the conventional structure of a ballast prism. Feasibility of using a 2×25 kV earth system using an artificial earth connection is confirmed, recommendations on its use are given. Authors substantiate allowable values of the rail—earth voltage and catenary supports, which practically exclude the occurrence of hazardous situations for personnel maintaining the track in sections with ballastless track superstructure.

scholarly journals A Novel Co-Phase Power-Supply System Based on Modular Multilevel Converter for High-Speed Railway AT Traction Power-Supply System

Energies ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 253
Author(s):  
Si Wu ◽  
Mingli Wu ◽  
Yi Wang
Keyword(s):  
Power Supply ◽  
High Speed ◽  
Power Supply System ◽  
Supply System ◽  
High Speed Railway ◽  
Traction Power Supply System ◽  
Traction Power Supply ◽  
Supply Mode ◽  
Power Supply Mode ◽  
Traction Power

The existing problems of the traction power-supply system (i.e., the existence of the neutral section and the power quality problems) limit the development of railways, especially high-speed railways, which are developing rapidly worldwide. The existence of the neutral section leads to the speed loss and traction loss as well as mechanical failures, all of which threaten the fast and safe operation of the train and the system. Meanwhile, the power quality problems (e.g., the negative sequence current, the reactive power, and the harmonic) can bring a series of problems that cannot be ignored on the three-phase grid side. In response, many researchers have proposed co-phase power-supply schemes to solve these two problems simultaneously. Given that the auto-transformer (AT) power-supply mode has become the main power-supply mode for the high-speed railway traction power-supply system, it has a bright future following the rapid development of the high-speed railway. In addition, there is no co-phase power-supply scheme designed for AT power-supply mode in the existing schemes. Therefore, the main contribution of this paper is to propose a specifically designed power-supply mode more suitable for the AT, as well as to establish the control systems for the rectifier side and the inverter side. In addition, for the proposed scheme, the operation principle is analyzed, the mathematical model is built, and the control system is created, and its functionality is verified by simulation, and its advantages are compared and summarized finally. The result proves that it can meet functional requirements. At the same time, compared with the existing co-phase power-supply scheme, it saves an auto-transformer in terms of topology, reduces the current stress by 10.9% in terms of the current stress of the switching device, and reduces the power loss by 0.25% in terms of the entire system power loss, which will result in a larger amount of electricity being saved. All of this makes it a more suitable co-phase power-supply scheme for the AT power-supply mode.

Improving the Efficiency of High-Speed AC Contact Suspension

2021 ◽  
Vol 5 (5) ◽  
pp. 39-43
Author(s):  
Maksim V. SHEVLYUGIN ◽  
◽  
Daria V. SEMENOVA ◽  
Keyword(s):  
Power Supply ◽  
High Speed ◽  
Single Phase ◽  
New Technologies ◽  
Alternating Current ◽  
Rolling Stock ◽  
New Materials ◽  
High Speed Railway ◽  
Electric Rolling Stock ◽  
Electrified Railways

When developing a high-speed contact suspension for railways electrified with alternating current, it is important to ensure that the electric rolling stock passes the neutral insert without turning off the current and without reducing the speed of movement. The article provides an analysis of previously developed devices in the field of power supply of electrified railways of single-phase alternating current, in which an attempt was made to pass an electric rolling stock of a neutral insert without disconnecting the load. The device of isolating coupling of a catenary and a neutral insert for high-speed railway lines electrified on alternating current is described. In this case, the passage of the neutral insert is carried out under current and braking of the electric rolling stock will not occur. Among other things, to improve the efficiency of high-speed contact suspension for railways electrified with alternating current, it is proposed to use new materials and new technologies that can be used in the device of insulating coupling of the catenary

Modeling and Optimization Design of Signal Interconnect Channel Considering Signal Integrity in Three Dimensional Integrated Circuits

2021 ◽  
Vol 16 (5) ◽  
pp. 773-780
Author(s):  
Bing-Jie Li ◽  
Zhen-Song Li ◽  
Yan-Ping Zhao ◽  
Zheng-Wang Li ◽  
Min Miao
Keyword(s):  
Performance Optimization ◽  
High Speed ◽  
Optimization Design ◽  
Channel Model ◽  
Transmission Loss ◽  
Coupling Effect ◽  
Signal Integrity ◽  
Signal Transmission ◽  
Equivalent Circuit Model ◽  
Transmission Performance

The signal integrity (SI) analysis of a high-speed signal interconnect channel composed of through silicon vias (TSVs) and horizontal re-distribution layers (RDL) is carried out, and the problems of SI, such as transmission loss, crosstalk and coupling effect in the transmission channel, are analyzed and studied. These signal integrity issues are considered in this paper, a signal interconnect channel model is proposed and the equivalent circuit model is deduced as well. Compared with the traditional one, this interconnect channel model has better performance in SI. Further sweep frequency analysis is carried out for different material parameters to achieve signal transmission performance optimization aimed at this model. Test samples of the proposed signal interconnect channel model are designed and fabricated according to the process index, and measured to verify the actual transmission performance. The design and optimization rule of high-speed signal interconnect channel are summarized which proved that the proposed structure has more advantages in signal transmission performance, and has important guiding significance for practical design.

Switchmode Hydraulic Power Supply Theory

2005 ◽  
Author(s):  
Jianwei Cao ◽  
Linyi Gu ◽  
Feng Wang ◽  
Minxiu Qiu
Keyword(s):  
Flow Rate ◽  
Dynamic Characteristics ◽  
Power Supply ◽  
Power Loss ◽  
High Speed ◽  
Hydraulic Pressure ◽  
Hydraulic Systems ◽  
Hydraulic Pump ◽  
Hydraulic Power ◽  
Supply Pressure

Switchmode hydraulic power supply is a new kind of energy-saving pressure converting system, which is originally proposed by the authors. It is mainly applied in multiple-actuator hydraulic systems, and installed between hydraulic pump and actuators (one switchmode hydraulic power supply for one actuator). It can provide pressure or flow rate that is adapted to the consumption of each actuator in the system by boosting or bucking the pressure, with low power loss, and conveniently, through high-speed switch valves, just like a hydraulic pressure transformer. There are two basic types of switchmode hydraulic power supply: pressure boost and pressure buck. Their structures and working principles are introduced. The dynamic characteristics of two typical types of switchmode hydraulic power supply, the pressure boost type and the pressure buck type, were analyzed through simulations and experiments. The performances were evaluated, and improvements on the efficiency of switchmode hydraulic power supply were proposed.

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