Design Of Switch Mode Power Supply Research Articles

Evaluation and continuous improvement of magnetic components material design skills in interdisciplinary switched-mode power supply

The design of switched-mode power supplies (SMPSs) is a material-electrical engineering interdisciplinary problem. The design of magnetic component materials can significantly affect SMPSs’ performances. In engineering education, the design and development of solutions is an important skill for engineering students. However, the traditional engineering experiments curriculum is shown as validation and single-disciplinary experiments as well as one-sided assessment results. To foster open-ended exploration, enhance students’ material design skills, and improve skills adaptation, students must tackle real engineering problems and develop practical design solutions. This paper proposes an exploratory factor analysis and knowledge graph-based method for evaluating and continuously improving magnetic components material design skills in the context of SMPS design tasks. First, we used the multiple imputation method to address the missing data. Each imputed data was analyzed to extract factors through parallel analysis, ordinary least squares estimation, and target rotation. Then, we identified four sub-skills: efficiency design skill, passive device design skill, power magnetic reduction design skill, and power economy design skill. The RMSEA for the four-factor model is 0.042, suggesting a good fit to the data. We established the relationships between these sub-skills and SMPS performance metrics. Furthermore, the average of the factor scores from each of the imputed datasets and the SMPS design constraints were combined to obtain the cut-off scores to evaluate engineering students’ achievements in these sub-skills. Finally, we constructed an SMPS magnetic components material knowledge graph, which could recommend specific experimental tasks, relevant knowledge areas, and SMPS performance metrics, providing personalized guidance to designers.

Analytical Approach of Designing Passive Filter for SMPS Load

The use of switch mode power supply (SMPS) load such as computer, laptop, etc in residential as well as commercial areas give rise to harmonics pollution in the electrical power distribution system which causes the quality of power poor and the function of equipment connected to the electrical system is affected. Many electrical appliances have an SMPS design that characteristically draws a distorted current that flows back to the input supply and causes distortion in the voltage waveform. To ensure the safe functioning of various electrical devices, there is a need for the implementation of effective harmonics mitigating techniques. Passive filters have been used for mitigating voltage and current harmonics. This paper proposed an analytical approach to designing the passive filter instead of trial and error or a complex approach for harmonics mitigation. The Simulation Model of SMPS is developed in MATLAB/Simulink and used for validating the proposed approach. Simulation results show the attractive findings of the proposed approach for harmonic mitigation with the improvement of the power factor.

GaN-Half-Bridge for Core Loss Measurements Under Rectangular AC Voltage and DC Bias of the Magnetic Flux Density

An accurate calculation of core losses is essential for the design of switched-mode power supplies. However, such predictions remain a challenge as core losses depend on various parameters, e.g., the waveform of the magnetic flux density, including its fundamental frequency and dc bias. To investigate the influence of dc bias, core loss measurements usually impose a dc current and, thus, dc bias of the magnetic field strength on ungapped toroid samples. However, hardware designers require the ac and dc excitation of the magnetic flux density. Therefore, this article proposes a half-bridge configuration to impose rectangular ac voltages on the core under test (CUT). By performing a pulsed operation in combination with an iteration method, the desired ac and dc excitation of the magnetic flux density can be obtained. GaN-HEMTs have been applied as they allow a printed circuit board design with low parasitic inductances and thus avoid ringing. The measurement setup is able to characterize magnetic materials at high frequencies for triangular magnetic flux density waveforms, including dc bias and different duty cycles. In addition, the influence of magnetic history on core losses can be studied, an issue usually not addressed in the literature. Moreover, the relationship between the dc bias of the magnetic field strength and the dc bias of the magnetic flux density is investigated. A simple functional approach, e.g., by using the initial magnetization curve, does not suffice to describe this relationship. Accordingly, core losses should be derived as a function of dc bias of the magnetic flux density for the results to be of practical use to hardware designers.

Fuzzy Cognitive Maps-Based Switched-Mode Power Supply Design Assistant System

Traditional engineering design approaches primarily solve technical problems and often ignore the importance of human factors. To reduce human errors and workload in power electronics, this paper proposes a switched-mode power supply design (SMPS) assistant system based on Fuzzy Cognitive Maps (FCMs). This system incorporates both technical requirements and human factors that involve designers' knowledge and skills in the SMPS design domain. First, we identify the critical concepts from power management lab kits and power electronics books, and extract latent sub-skills of SMPS design using exploratory factor analysis to build the starting concept list of FCM. Second, we use factor analysis and correlation analysis to determine the causal weights between the captured components to build the initial FCM based on the starting concept list of FCM. Third, through interviews with subject-matter experts, we get their inputs on the initial main map and capture their individual FCMs. Then, we integrate experts' individual FCMs with different weights. After that, we determine the degree of fuzzification of the threshold function through analyzing data collected based on the prediction results of the only decision concept in the proposed FCM - SMPS quality. Two WHAT-IF scenarios are analyzed based on different inputs using the FCM Expert tool. The scenario test results provide guidelines to designers in terms of knowledge or skills improvements and power supply debugging. Finally, we evaluate the proposed system using eight scenarios. The evaluation results of components' actual states are consistent with their preferred states, which suggests that the proposed FCM-based assistant system is reliable and effective. The proposed system provides useful guidelines in terms of knowledge or skills improvements for SMPS designers and can help improve the power supply design process.

Tolerance‐based reliability and optimization design of switched‐mode power supply

AbstractDue to its high efficiency and low power consumption, switched‐mode power supply (SMPS) represents the development trend of the stabilized voltage power supply. However, tolerance has become one of the key factors in the design of SMPS because of the process fluctuation of electronic components, unstable input parameters of the circuit system, influence of working conditions and environment, and the effect of aging. In order to improve the reliability of SMPS and reduce the manufacturing cost, this paper proposes a reliability analysis and optimization design method based on the tolerance and sensitivity analysis. Finally, this method is applied to the tolerance design for the positive switching power supply of the SMPS circuits, and the optimal tolerance design scheme is obtained. Furthermore, the reliability and probability density curves are evaluated.

An Accurate and Efficient Approach for High‐Frequency Transformer Parameter Extraction

Accurate parasitic parameter extraction of high-frequency transformers is one of the key techniques to efficiently design a Switched-mode power supply(SMPS). An approach to accurately and efficiently extract the parasitic parameters of high-frequency transformers is proposed. The high-frequency transformer is first decomposed into first-order RL and second-order RLC circuits according to inherent step response characteristics. Through the measured discharging pulse and damped oscillation responses of the high-frequency transformer excited by a square wave, we can extract the equivalent circuit parameters through fitting the responses with Particle swarm optimization(PSO). The equivalent circuits of the high-frequency transformer with the desired parameters are obtained for the SMPS design. We validate the effectiveness and accuracy of the proposed method with simulations and measurements.

Evaluation Method of Flyback Converter Behaviors on Common-Mode Noise

Common-mode (CM) conduction electromagnetic interference (EMI) is a challenge for switched-mode power supply (SMPS) designers. A flyback converter is a traditional topology used in low-power isolated applications. The size and cost of EMI filters are important considerations for higher power density and lower cost of SMPS design. In most cases, the CM current is generated by voltage pulsation (dv/dt) assigned on the primary winding and the secondary winding. The CM current conduction paths can be mainly categorized into two categories. One is the interwinding parasitic capacitance of the transformer, and the other is the parasitic capacitance between the semiconductor switches and the protective ground. This paper proposed an evaluation method to measure the equivalent CM noise capacitance of the two main CM current conduction paths, respectively. Then, this paper proposed a CM noise cancellation scheme based on the transformer winding design combining the measurement technique and the FEM simulation tool. Planar transformers with PCB windings also have advantages in low profile, good heat dissipation, and good stray parameter consistency. Based on these considerations, an 18-W adapter is designed and tested to verify the effectiveness of the proposed evaluation method and the design scheme.

English

English

Design and Analysis of a Novel Interleaving LLC SMPS with Load Current Sharing Performance

LLC series resonant topology has been widely adopted in many kinds of power converters for its high frequency, high efficiency and high power density advantages. However, the ordinary topology of a single-phase LLC is not fit to be used in low-voltage high-current output field for its relative larger output voltage ripple. In order to provide a low voltage and high current output using a LLC topology, a novel interleaving LLC switched-mode power supply design was proposed to reduce output voltage ripples ripple in this paper. This design used two hardware measures to automatically ensure a good load current sharing effect between two-branch LLC circuits and avoid the PFM difficulties of the active current sharing methods. The principles and design procedures of this novel LLC converter were introduced in detail and verified by Saber simulation results. A 1.5kW DC/DC prototype was built up in the end and the experiment results showed that a good current sharing performance was achieved.

Efficient Switch Mode Power Supply Design with Minimum Components for 5W Output Power

This paper presents a flyback technology in power conversion aimed at increasing efficiency and power density, reducing cost and using minimum components in AC-DC conversion. The proposed converter provides these features for square waveforms and constant frequency PWM. It is designed to operate in a wide input voltage range of 75-265VAC RMS with two output voltages of 5V and 20V respectively and full load output power of 5W. The proposed converter is suitable for high efficiency and high power density application such as LCDs, TV power modules, AC adapters, motor control, appliance control, telecom and networking products.

スイッチング電源設計における熱流体シミュレーションの利用

スイッチング電源設計における熱流体シミュレーションの利用

A new flyback-current-fed push-pull DC-DC converter

This paper introduces a new flyback-current-fed push-pull DC-DC converter whose significant advantages in comparison with the conventional one are a reduction in the number of output diodes and unified output characteristics to represent both the buck and the boost operation modes in the continuous conduction mode. Theoretical analysis, design methodology and experimental results taken from a 600 W 25 kHz laboratory prototype are presented in this paper. The circuit introduced is suitable for switching mode power supply design and power factor correction applications as well.