Switching Power Supply Research Articles

Holographic Acoustic Tweezers for 5-DoF Manipulation of Nanocarrier Clusters toward Targeted Drug Delivery.

Acoustic tweezers provide unique capabilities in medical applications, such as contactless manipulation of small objects (e.g., cells, compounds or living things), from nanometer-sized extracellular vesicles to centimeter-scale structures. Additionally, they are capable of being transmitted through the skin to trap and manipulate drug carriers in various media. However, these capabilities are hindered by the limitation of controllable degrees of freedom (DoFs) or are limited maneuverability. In this study, we explore the potential application of acoustical tweezers by presenting a five-DoF contactless manipulation acoustic system (AcoMan). The system has 30 ultrasound transducers (UTs) with single-side arrangement that generates active traveling waves to control the position and orientation of a fully untethered nanocarrier clusters (NCs) in a spherical workspace in water capable of three DoFs translation and two DoFs rotation. In this method, we use a phase modulation algorithm to independently control the phase signal for 30 UTs and manipulate the NCs’ positions. Phase modulation and switching power supply for each UT are employed to rotate the NCs in the horizontal plane and control the amplitude of power supply to each UT to rotate the NCs in the vertical plane. The feasibility of the method is demonstrated by in vitro and ex vivo experiments using porcine ribs. A significant portion of this study could advance the therapeutic application such a system as targeted drug delivery.

Printed Circuit Board Electromagnetic Compatibility Design of LLC Resonant Converter Based on Field-Line Coupling Effect

With the development of switching power supply in the direction of high efficiency, high integration, miniaturization and intelligence, LLC resonant converter has been widely used for its advantages of low loss and high efficiency. As an indispensable part in the design, the circuit board is responsible for the dual connection of the electrical part and the mechanical part of the LLC resonant converter. With the increasing of integration and distribution density of components, the EMC problem becomes more and more serious. In this paper, LLC resonant converter PCB is taken as an example to guide the selection and layout of active components based on field-circuit combination method, and the signal integrity of the system is analyzed. Finally, an experimental platform is built to verify the feasibility and effectiveness of the proposed method.

Abrupt changes detection using wavelet-based denoising analysis

Switching power supply is an essential power supply method that exists in the development of the electronic information industry. Drive power supply has various quality problems, primarily due to the loss of power inductors; for power inductor capacity testing, making a feasibility assessment is of great significance. In this study, we present a wavelet-based approach for detecting sudden changes in the power inductor current curve. To reliably identify rapid changes in the saturation of the inductor current after energization, the discrete wavelet transform is utilized to analyze the signal within a specified subset of all scaling and translation values, displaying different local signal characteristics.

Quasi-Resonant Half-Wave Buck Converter with Non-Isolated High Side Switching Techniques

Power density of the power converters became one of the most important parameters in many applications. Power density is increased by reducing the losses through use of better performing components and circuit topologies. It can be increased further by reducing the size of filter components through increasing the switching frequency. In hard-switching converters however, losses due to switching will eventually render this method not applicable. Instead, resonant converters are utilized in many high-frequency switched power supplies. Soft-switching feature of these converters provide increased efficiency due to decreased switching losses. Such converters exploit the resonance of the specific inductors and capacitors in the circuit called as resonant tank elements. Resonance behavior is used in order to eliminate turn-on or turn-off losses. Existing power converter topologies can be modified to create the resonance during switching period. Such converters are called as quasi-resonant converters. This paper presents analysis and design of Zero Current Switching (ZCS) half-wave quasi-resonant buck converters. In this topology, high-side switching is required. Two different non-isolated high-side switching techniques are utilized. Experimental results are obtained for light load to full load operation. Both techniques are compared in detail.

EMI Analysis of a Switching Power Supply

Switching power supply is easy to produce electromagnetic interference in the working process. Switching power supply is both an interference source and a sensitive device. Therefore, the boost circuit of switching power supply is modelled and simulated. It is concluded that the surge current and peak voltage generated by the boost circuit are the main causes of electromagnetic interference. According to the reasons, the electromagnetic interference suppression measures are proposed. It mainly includes three measures, namely adding capacitors at both ends of the switching tube, adding a filter circuit at the low voltage input end of the switching power supply, adding an optical coupler equipment and adding a common-differential-mode synthetic choke coil filter. These measures all effectively reduce the influence of electromagnetic interference of the switching power supply, and they are beneficial to improve the reliability of the switching power supply.

Design and Analysis of Micron Chip Transformer

With the rapid progress of power electronics high frequency conversion technology, the traditional magnetic components are more and more difficult to meet the requirements of modern electrical product design. In contrast, chip magnetic components have the advantages of small volume, low height and light weight in structure, small leakage inductance, low electromagnetic interference and high efficiency in electrical characteristics. They are very attractive in switching power supply with high frequency and high-power density. This paper studies the design and analysis of components, which has done useful work for the development of component magnetic design.

Enhancement of Power Quality in Power Distribution Systems Using FC- TCR Based Compensation Systems

The development of modern electronic systems and increasing number of application areas (computers, office equipment, rectifiers, converters, speed control devices, uninterruptible power supplies, switched power supplies) has led to harmonic generation and reduced energy efficiency. The majority of loads are inductive in nature and the draw of reactive power has increased in networks and transmission lines resulting in problems with power quality. In addition to efficient power flow in transmission systems, there is also a need to compensate for the reactive power flow in order the meet the requirements of the load and system. As an alternative to traditional solutions, FACTS (Flexible Alternating Current Transmission Systems) has been developed in order to operate electrical systems efficiently and improve stability and power quality. Technological applications such as SVC, STATCOM, SSSC and active harmonic filter are becoming widespread in order to improve power quality. In this study, applications within the scope of FACTS systems are explained and analysis of a fixed capacitor-thyristor controlled reactor (FC-TCR) to improve power factor is discussed. A circuit model of the FC-TCR is developed as a simulation and used to investigate how power factor may be kept within desired limits by adjusting the firing angle of the thyristors under different load conditions. A comparative evaluation has been carried out to determine the effect of FC-TCR by presenting results before and after the load compensation process is applied. From the simulation it is observed that reactive power compensation can be achieved even for varying linear loads.

Programmable Current Source Design for Multi-channel Magnetic Field Generator* Programmable current source

The three-dimensional motion of magnetic micro-robots requires the control of multiple magnetic field generators working simultaneously. The current program-controlled current sources in the market are generally expensive and it is difficult to control multiple program-controlled current sources by a single controller to change the output current at the same time. In order to compress the experimental cost, reduce the experimental threshold, realize the simultaneous control of multiple magnetic field generators and make them work stably, this paper proposes a special program-controlled current source design for multiple magnetic field generators, and verifies the feasibility of the design through experimental tests. The results show that the dedicated current source is able to output 0.3∼6.5A under ±12V switching power supply test when each current source is connected to a 1.5 ohm solenoid coil with internal resistance. The system meets the requirements of 3% or less output current error and fast response time while greatly reducing costs and achieving good interactivity.

Analysis and Design of a Modular Switched Capacitor Converter With Adjustable Output Voltage in DC Microgrid

A high conversion ratio, high efficiency and miniaturized switching power supply converter is an important part of DC microgrid. Switched capacitors have been widely used in low-power voltage conversion applications, for small size, light weight, high efficiency, etc. Due to the structural characteristics of the switched capacitor topology, the transformation ratio of the circuit cannot be adjusted continuously. In response to this need, some control methods are proposed, most of which require more complicated control circuits or parameter design. A modular switched capacitor converter with adjustable output voltage is proposed in this paper. The topology can be modularized as required. More switched capacitor module provides higher output power and higher efficiency. More voltage regulating module provides wider output adjustment range. Its control method is simple and can be expanded to a high-power power supply as needed. The advantages of small size and high efficiency of switched capacitor topology are also retained. A 4 to 1 prototype with 12V output is built to verify the proposed topology. The peak efficiency of the prototype is 95.34% and the full load efficiency is 93.82%.

Failure causes and solutions of relay protection switching power supply

Relay protection device plays a key role in the stable operation of power grid, and the failure of switching power supply is the main reason for the unstable operation of relay protection device. This paper studies the failure causes of relay protection switching power supply, and concludes that electrolytic capacitor is the key component leading to the failure of power plug-in. At the same time, the failure mechanism and life influencing factors of aluminum electrolytic capacitor are deeply studied, and the improvement measures are put forward. According to the research results of this paper, the switching power supply has the characteristics of high reliability and long life.

A Case Study of a Small Switching Power Supply Process: Based on the Module of Production

With the rapid development of electronic products, technology plays an important role in the management and production of electronic products. In the increasingly fierce market competition, excellent technological process is also one of the important bargaining chips for the success of an enterprise, and it is the embodiment of the level of enterprise management ability. As a product of modern power electronic technology, switching power supply represents the development direction of regulated power supply, and it is an industry pursued by many electronic companies. Switching power supply manufacturers should not only pay attention to the miniaturized power module technology, but also do a good job in the quality management of the production process. Only by doing a good job in the production process design, can better ensure the function and quality of the miniaturized switching power supply module, and help enterprises gain an advantage in the market competition. Using the method of case study, this article interviewed the small switching power supply design engineers and production workshop workers in Factory A. combined with literature analysis and on-site observation, it is proposed that the production process of switching power supply module should involve three stages: before production, during production, and after production, which include 8 links: production preparation, coil production, the device welding assembly, cleaning, inspection, potting, sealing and marking. In particular, the requirements and precautions of each step are described in detail.

The Implementation of Synergetic Control for a DC-DC Buck-Boost Converter

In order to solve the nonlinear control problem of DC-DC Buck-Boost converter in switching power supply, the synergetic control method is adopted and applied to DC-DC Buck-Boost converters. Firstly, according to the characteristics of DC-DC Buck-Boost converter, we choose an improved macro-variable during the design of synergetic controller, which reduces the dynamic response time of the system. The synergetic control law of the system is also derived. Then, considering of the system robustness to the input voltage changes, we add a compensation amount to the control law, which can improve the control precision and make the system a good inhibitory effect to parameter change. Finally, the simulation results show the effectiveness of the proposed method.

Adiabatic CMOS‐Based Electrostatic MEMS Actuation for Reduced Dynamic Power and Switching Activity

The basic purpose of MEMS actuation is to miniaturize the actuators and sensors for applications in nanoelectronics. The transistor switching current and power supply noises due to voltage drops across the metal lines can impair circuit timing and performance, posing a continuing problem for high‐performance chip designers. This work presents an empirical concept of a reconfigurable charge pump based on FPGA for electrostatic actuation of the Microelectromechanical System (MEMS). The goal of the design is to produce enough on‐chip voltages for actuating the MEMS that are continuously adaptive and reconfigurable. In this proposed method, pumping capacitors lying in the range of 1‐pF have been deployed to decrease the area of design concerned. The various voltages are programmable digitally and created by dynamically altering the number of phases as well as the clock drive levels. The dynamic model is designed by adjusting the number of stages to produce on‐chip voltages including clock drive speeds, assuming a purely capacitive load. The proposed model’s power consumption can be lowered in the steady state by lowering its clock frequency and electrostatic MEMS actuators with capacitive load. An average of 0.62 W is dissipated by the circuit when the eight stages are triggered. Consequently, with adiabatic and without adiabatic architecture, 0.0186 mW of minimum power difference is obtained.

Design and Analysis of an Automatic Power Changeover with Backup

The stability of the power supply in Ghana and another part of Africa is a major concern to the community and shop owners. The need for alternative power supply support and switching of load between two power sources. The system will eliminate the need for manual intervention by sensing the main gridline supply and switching to a backup source. Automation charger over to the backup source will eliminate the delay and provide efficiency in production. The system will automatically switch back when main gridline power is restored back. the system uses a microcontroller as the main automatic changing over the process and other component consists of a power supply circuit consisting of a step-down transformer, rectifier, filter capacitor, voltage regulator, and sg3525 which perform the oscillation convention from DC to AC Renewable energy sources generating direct current will require inverters to produce the alternating current necessary for domestic and industrial use The design, construction, testing of this circuit, is satisfactorily in switching from mains supply to generator/renewable energy source(s) and vice versa.

ВЕКТОРНОЕ УПРАВЛЕНИЕ ЭЛЕКТРОПРИВОДОМ НА ОСНОВЕ ВЕНТИЛЬНОГО ДВИГАТЕЛЯ С ДИСКРЕТНОЙ КОММУТАЦИЕЙ ОБМОТКИ

The article considers the possibility of implementing phase vector control (FVU) of a synchronous motor with permanent magnets in the thyratron motor mode. The characteristics of the FVU with three methods of discrete commutation of the three-phase winding are considered: six-stroke 120- and 180-degree and twelve-stroke 150-degree. A comparative assessment of the efficiency of the PVF is carried out in terms of expanding the range of implemented mechanical coordinates and energy indicators, both with different methods of discrete switching and with respect to sinusoidal power supply. It is shown that 120-degree switching is the most advantageous in terms of energy indicators. However, with it, the values of the maximum achievable speeds and moments weakly depend on the angle of commutation θ, therefore, operation is recommended at a constant θ = 0, corresponding to the efficiency value close to the maxi­mum in a wide range of speeds. With 180-degree commutation, the FVU allows you to adjust both the maximum speed and the maximum torque. However, with small values of the relative inductance of the winding, which refers to the ratio of inductive resistance to active, this method of regulation is ineffective due to low efficiency and is inferior in this indicator to both 120-degree commutation and the case of sinusoidal power supply. As the relative inductance increases, the difference between the case of sinusoidal power supply and 180-degree switching decreases. The use of 150-degree commutation allows, on the one hand, to increase efficiency while maintaining the ability to adjust coordinates, on the other hand, reduces the pulsation of the motor torque, expanding the possible scope of the drive.

СРАВНИТЕЛЬНАЯ ОЦЕНКА СПОСОБОВ ПИТАНИЯ СДПМ В РЕЖИМЕ ВЕНТИЛЬНОГО ДВИГАТЕЛЯ

The article provides a comparative assessment of various ways of powering a synchronous motor with permanent magnets (PMSM) in the mode of a thyratron motor (TM). Numerically, on analytical and computer models, mechanical ω = f(M), the dependence of speed on electromagnetic torque, and energy ηэ = f(M), the dependence of elec-tromagnetic efficiency are calculated from the moment, the characteristics of the motor with sinusoidal power supply and discrete switching with different values of the relative inductance of the winding. Moment pulsations are investigated. The three most common methods of discrete degree commutation are considered – 120, 180 and 150. It is shown that discrete 120 degree commutation provides the highest value of ηэ in comparison with other methods, and the mechanical character-istics are approximately the same in appearance with different power supply methods. The study of moment pulsations has shown that discrete switching without additional measures cannot compete in this indicator with the case of sinusoidal power supply, which theoretically has zero moment pulsations. However, the use of 150 degree commutation makes it possible to significantly reduce them, bringing them closer to 2…3 %. Curves are given that allow an approximate estimate of the expected moment pulsations for all discrete switching methods. Practical recommendations on the choice of the method of powering the PMSM are given.

Research on Double-loop Control Method of Voltage Drop DC-DC Converter Based on Peak Current Mode

This paper mainly studies the dual-loop control algorithm based on peak current mode. The working principle and system structure of the step-down switching power supply are introduced. The system uses PWM modulation and peak current mode to design the converter, and simulates its function in MTALAB/simulink. The result shows that the step-down circuit can basically realize the expected function, with high conversion efficiency and stable output voltage.

Immunity Performance of Switching Power Supply based on the Presence or Absence of Malfunctions under Actual Load

Immunity Performance of Switching Power Supply based on the Presence or Absence of Malfunctions under Actual Load

Optimal Test Point Placement Based on Fault Diagnosability Quantitative Evaluation

The optimal test point placement problem in existing research results is mainly limited to the qualitative study of whether faults can be diagnosed without considering the difficulty of diagnosing faults. We proposed an optimal test point placement approach based on fault diagnosability quantitative evaluation to solve the above problem. First, the fault diagnosability is quantitatively evaluated based on the maximum mean discrepancy (MMD). Then, the problem of optimal test point placement is considered a multi objective optimization problem. The optimal test point set is solved using the multi objective sparrow search algorithm (MOSSA) based on the fault diagnosability quantitative evaluation results, considering limitations on the test point number, reliability, and cost. Finally, the proposed approach is used to optimize the placement of test points in the switching power supply system. The simulation results show that only three test points need to be placed to make the system meet the fault diagnosability requirements. Two test point placement schemes are obtained, which can be selected according to different practical requirements. The experimental results illustrate that the proposed approach can optimize the system test point placement while ensuring good fault diagnosability.

Method of optimal technical diagnostics and repair low-power switching power supplies

Method of optimal technical diagnostics and repair low-power switching power supplies