Low Ripple Research Articles

A novel boost power converter suitable for bearingless switched reluctance motor with wider rotor teeth

Abstract Aiming at the problem that the excitation current build-up speed of the bearingless switched reluctance motor with wider rotor teeth (BSRMWR) is too slow during commutation, this paper proposes a simple structured boost power converter. When the motor is commutation, it uses the winding demagnetization energy to quickly establish the excitation current for the latter phase winding and realizes the low torque ripple operation of the motor on the basis of ensuring the stable levitation of the motor. The topology and working status of the novel power converter are analyzed. On this basis, a 12/8 pole single-winding BSRMWR driving system based on the novel boost power converter is constructed. Through Matlab/Simulink simulation, the feasibility and effectiveness of the novel power converter are verified.

A study on a low input current ripple high voltage gain cuk converter

Abstract In the realms of photovoltaic power generation and fuel cells, the application of traditional DC-DC boost converters faces significant constraints due to insufficient gain and pronounced input current ripple. This paper presents a design for a Cuk converter with low input current ripple and high voltage gain based on the conventional Cuk topology. The design incorporates a passive ripple circuit and a coat circuit. The operational principles of the converter are analyzed, followed by the construction of a simulation model in PSIM. Simulation results not only validate the theoretical analysis but also affirm the feasibility of the proposed converter.

Electromagnetic Characteristic Analysis of a Negative-Salient Hybrid Permanent Magnet Motor for Electric Vehicles

Negative-salient permanent magnet motors (NSPMMs) have a potential application in the field of electric vehicles (EVs) due to their wide constant-power speed range and high efficiency. However, the researches of NSPMMs used for EVs and the relationships between the design parameters of the motor and drive performances of the EV are still absent. First, the operating characteristics of permanent magnet drive motors are investigated. Second, the relationships between the distribution of the driving cycles of the EV and the design parameters of the motor are summarized. Then, a negative-salient hybrid permanent magnet motor with excellent performances in the full-speed range and remedies for its negative impact are proposed. The electromagnetic performances of the proposed topology are compared with the conventional motor by finite element method and the performance evaluation of the electrical driving system is carried out. Finally, a prototype is manufactured and tested. The simulation and experimental results show that the proposed motor exhibits favorable characteristics such as low torque ripple, wide constant-power speed range, high efficiency in a wide speed range and low rare-earth consumption. The results verify the feasibility of the proposed topology applied to EVs.

Enhanced Control of Polymer Electrolyte Membrane Fuel Cell Fed Basic Series Positive Super Voltage Lift Luo Converter Using Interval Type-2 Fuzzy Logic

An eco-friendly and renewable energy source, Polymer Electrolyte Membrane (PEM) fuel cells offer various advantages such as stability and efficiency. The present study aims to control output voltage of PEM fed basic series positive super voltage lift luo (PSVLL) converter. The model, which consists of a fuel cell and a basic series PSVLL converter, was designed in Matlab/Simulink simulation environment. The control of the PSVLL converter output voltage was performed using an interval type-2 takagi-sugeno-kang fuzzy logic (IT2TSKFL) and type-1 takagi-sugeno-kang fuzzy logic (T1TSKFL) controllers comparatively. The simulation study results demonstrated that the PEM fuel cell fed basic series PSVLL converter reached optimal current and voltage values with IT2TSKFL under nominal and different operating conditions. Moreover, IT2TSKFL improved average settling time of control system by 22.335% compared to T1TSKFL controller.

Topology and parameter optimization of IPM motor considering mechanical strength by stress and connection constraints

PurposeThe purpose of this study is to apply the topology and parameter optimization (TPO) to interior permanent magnet (IPM) motors to obtain the optimized shape with higher torque, lower ripple and sufficient mechanical strength.Design/methodology/approachThe constraints regarding the maximum stress, connectivity and mesh quality were considered to achieve not only high electrical performance but also high mechanical strength. To enhance the accuracy of the finite element analysis of the elastic analysis, this paper used body-fitted mesh adaptation technique to avoid the stress concentration.FindingsThe proposed method in this study resulted in feasible shapes with sufficiently high strength compared to previous studies. It is also shown that TPO yielded IPM motors with higher torque compared to topology optimization (TO) with fixed parameters.Practical implicationsDifferent from the existing studies on topology optimization of IPM motors, the mechanical strength is even considered by evaluating the stress values. Therefore, in the practical phase, geometries can be designed that are less likely to be damaged due to deformation, even in the high-speed rotation range.Originality/valueThis paper performed TO and parameter optimization (PO) simultaneously, considering not only the electrical performance but also the mechanical strength. Furthermore, the mechanical strength was evaluated more precisely by devising the elastic analysis conditions and mesh generation.

Mitigation of Low Harmonic Ripples Based on the Three-Phase Dual Active Bridge Converter in Charging Station Applications

Mitigation of Low Harmonic Ripples Based on the Three-Phase Dual Active Bridge Converter in Charging Station Applications

Low-power DC-DC converters for smart and environmentally-friendly electric vehicles: design, simulation, and fabrication on a glass substrate

This research focuses on evaluating and comparing different DC-DC converter designs, specifically for low power applications. The study considers inductor-based, switching capacitor, and linear voltage regulator (LVR) DC-DC converters. While there has been critical investigation of DC-DC converters in the literature, there is a gap in assessing their performance based on a comprehensive set of conflicting parameters. Additionally, there is a lack of research on matching the most suitable DC-DC converter with specific low power applications. The chosen application for this study is a DC-DC converter on a glass substrate, specifically for smart glass in electric vehicles. The research presents a complete process that includes design, simulation, layout, fabrication, and measurement. Through simulations, a 4.8 V to 3.3 V buck converter is recommended, demonstrating an almost ideal response time and minimal output ripples. Experimental measurements also confirm a low output ripple of 0.3 %. By addressing this research gap and providing a comprehensive evaluation of DC-DC converters, this study contributes to the development of efficient and reliable power solutions for smart glass applications in electric vehicles.

Design and Optimization of External Rotor Consequent Pole Permanent Magnet Motor with Low Iron Loss and Low Torque Ripple

To reduce the iron loss and torque ripple of an external rotor consequent pole (ERCP) motor used in an electric vehicle air-conditioning compressor, the magnetic pole structure of the motor was improved, and an unequal piecewise consequent pole (CP) structure was designed. The performance of the motor is optimized by reducing the harmonic content in the air gap flux density and reducing the iron saturation degree of the motor. The designed CP structure can significantly reduce the iron loss and torque ripple of the motor. Based on the Taguchi method, the optimal size parameters of the unequal piecewise CP structure are determined, and the final optimization design scheme is obtained. The results of finite element simulation and high-precision iron loss model show the following: compared with the original motor, the iron loss and torque ripple of the motor with the final optimized design scheme are significantly reduced.

Interleaved step-down converter with capacitor-diode voltage splitter and minimum switches for low current ripple and extra-low voltage ratio

This paper proposes an interleaved step-down converter (ISDC) with a capacitor-diode voltage splitter. Even though the ISDC only utilizes two active switches, it can significantly step down a high input voltage to a much lower level and achieve interleaved current at output and continuous current at input without using an extreme duty ratio. In addition, the ISDC is capable of sharing output current equally between two interleaved paths by controlling the two switches. Therefore, the ISDC has lower current ripples and reduces EMI noise. The ISDC can be easily expanded only by adopting capacitors and diodes for a much higher conversion ratio, avoiding using any active switch. A comprehensive analysis of ISDC is presented, including operation principle, steady-state analysis, design consideration, expendability of the power stage, and converter comparison. A prototype of 500 W is fulfilled to deal with 400-V input and 24-V output, which has verified the accuracy of the theoretical analysis and validated the converter. Experimental results demonstrate that the ISDC achieves a peak efficiency of 92.74% at 350 W and 92.09% at full load. If synchronous rectifiers are employed, the peak efficiency can be up to 94.73%.

A novel soft‐switching quadratic high voltage gain trans‐inverse DC/DC converter

AbstractThis paper suggests a new non‐isolated high step‐up DC/DC converter with soft‐switching performance and low input current ripple for renewable energy generation systems. In this introduced circuit, a three‐winding coupled‐inductor combined with a quadratic boost circuit and voltage multiplier cell to obtain high voltage gains. The advanced features of the proposed topology are its ultra‐high voltage gain, soft‐switching performance, low voltage stress across the switching components, continuous input current with low ripple, and the existence of a common ground between the input source and output load. Due to the partial trans‐inverse property in the suggested topology, higher voltage gains can be achieved under smaller turns ratios of the coupled in comparison to the other typical topologies, which leads to efficiency improvement. Moreover, in this introduced circuit, the voltage stress on the single power switch is mitigated using a regenerative clamp circuit. The theory and operating principle of the suggested converter, along with the steady‐state analysis and efficiency interpretation of the proposed converter are discussed in detail. Finally, to verify the theoretical analysis, a 200 W (25 V/400 V) sample prototype is established.

Design and shape optimization of interior permanent magnet synchronous machine based on hybrid cores

By designing stator teeth using grain-oriented sheets (GO) and other parts still with non-grain-oriented sheets (NGO), the electromagnetic performance of the interior permanent magnet synchronous machine (GO-IPMSM) can be improved greatly. As the stator core of the designed GO-IPMSM is a hybrid core that is composed of two different silicon sheets, both the electromagnetic and mechanical performances are affected by the stator joint shape between GO and NGO sheets. Meanwhile, with the adoption of GO, the torque ripple of GO-IPMSM is increased though the average torque is increased as well. For reducing the torque ripple, optimizing the rotor barrier shape is an effective way. In this paper, the piecewise linear interpolation method is employed for establishing the stator joint shape between GO and NGO sheets, and the polynomial method is proposed to establish the rotor barrier shape. Through the analysis, it can be seen that the stator joint shape plays a strong role in affecting the mechanical performance of the GO-IPMSM, while the effect on the electromagnetic performance is weak. The genetic algorithm is used to optimize the rotor barrier shape for achieving high average torque and low torque ripple. Lastly, a quick and accurate efficiency map calculation method based on the Kriging model is proposed for GO-IPMSM with less finite element method (FEM) samples are required.

High-speed tooth-coil permanent magnet synchronous machine for motorized spindle application

The slender shape of the driving machine leads to a low rigidity and large axial thermal elongation of the motorized spindle, which deteriorates the machining precision. To solve these problems and pursue a more compact size, this paper investigates the feasibility of using a tooth-coil permanent magnet synchronous machine in a high-speed spindle, replacing the original motor that has the conventional distributed winding. Comprehensive performance and behavior of machines with distributed and tooth-coil windings are comparatively analyzed, in terms of the essential torque ripples, winding inductances, electromagnetic losses, rotor integrity, and heat dissipation of the spindle. Thorough numerical simulation results indicate that the newly designed tooth-coil winding solution shows significant advantages over the original design, regarding high rotor rigidity, low torque ripples, reduced electromagnetic losses, and reduced shaft thermal elongation. Prototypes and test setups for the high-speed tooth-coil machine are built, where preliminary measurements are carried out to validate the analysis results and system design.

Speed Sensorless Control System of Five‐Phase Induction Motor Based on Linear Active Disturbance Rejection Control and Adaptive Full‐Order Observer

As the simplest type of multi‐phase induction motor, the five‐phase induction motor is suitable for applications that require high power and reliability due to its advantages such as low noise, low torque ripple, and strong load capacity. To address the problem that the speed encoder is easily affected by external environmental interference, a speed sensorless vector control strategy combining linear active disturbance rejection control and adaptive full‐order observer is proposed. Compared with the traditional speed sensorless vector control strategy, this paper's proposed method designs three first‐order linear active disturbance rejection controllers instead of traditional proportional‐integral controllers for speed control. Experimental results show that the proposed strategy exhibits stronger anti‐interference ability under load disturbance, improving the overall robustness of the speed sensorless control system. © 2024 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.

Sub-bandgap photo-response of black silicon fabricated by femtosecond laser irradiation under water

Here we propose a method to fabricate black Si without the need for any chalcogenide doping, accomplished by femtosecond (fs) laser irradiation in a liquid environment, aiming to fabricate the infrared detector and investigating their optoelectronic performance. Multi-scale laser-induced periodical surface structures (LIPSSs), containing micron sized grooves decorated with low spatial frequency ripples on the surface, can be clearly observed by SEM and 3D confocal microscope. The generated black Si demonstrates superior absorption capabilities across a broad wavelength range of 200-2500 nm, achieving an average absorptance of up to 71%. This represents a notable enhancement in comparison to untreated Si, which exhibits an average absorption rate of no more than 20% across the entire detectable spectrum. A metal-semiconductor-metal (MSM) type photodetector was fabricated based on this black Si, demonstrating remarkable optoelectronic properties, specifically, it attains a responsivity of 50.2 mA/W@10 V and an external quantum efficiency (EQE) of 4.02% at a wavelength of 1550 nm, significantly outperforming the unprocessed Si by more than five orders of magnitude. The great enhancement in infrared absorption as well as the optoelectronic performance can be ascribed to the synergistic effect of the multi-scale LIPSSs and the generated intermediate energy levels. On one hand, the multi-scale structures contribute to an anti-reflection and light trapping property; on the other hand, the defects levels generated through fs laser ablation process under water may narrow the band gap of the Si. The results therefore underscore the remarkable potential of black Si processed by fs laser under water for the application of photodetection, especially in the near-infrared band.

Research on Hybrid Rectifier for High Power Electrolytic Hydrogen Production Based on Modular Multilevel Converter

Aiming at the problem that silicon-controlled rectifiers (SCR) and pulse width modulation (PWM) rectifiers cannot balance high power levels, high hydrogen production efficiency, and high grid connected quality in the current research on rectifier power supplies for electrolytic hydrogen production, a new hybrid rectifier topology based on a modular multilevel converter (MMC) is proposed. The hybrid topology integrates a silicon-controlled rectifier (SCR) with an auxiliary power converter, wherein the SCR is designated as the primary power source for electrolytic hydrogen production. The auxiliary converter employs a cascaded modular multilevel converter (MMC) and an input-series-output-parallel (ISOP) phase-shifted full-bridge (PSFB) arrangement. This configuration allows the auxiliary converter to effectively mitigate AC-side harmonics and minimize DC-side ripple, concurrently transmitting a small amount of power. The effectiveness of the hybrid rectifier in achieving low ripple and harmonic distortion outputs was substantiated through hardware-in-the-loop experiments. Notably, the hybrid topology is characterized by its enhanced electric-to-hydrogen conversion efficiency, elevated power density, cost efficiency, and improved grid compatibility.

A Simultaneous Energy Transferring SIBO Converter Achieving Low Ripple and High Efficiency for AMOLED Applications

A Simultaneous Energy Transferring SIBO Converter Achieving Low Ripple and High Efficiency for AMOLED Applications

Easily extensible interleaved high step-up boost converter with low current ripple and low voltage stress

Easily extensible interleaved high step-up boost converter with low current ripple and low voltage stress

High-Efficiency Multiphase Stacked Interleaved DC-DC Buck Converter with Very Low Output Current Ripple and Low Current–Voltage Stress

High-Efficiency Multiphase Stacked Interleaved DC-DC Buck Converter with Very Low Output Current Ripple and Low Current–Voltage Stress

Torque Ripple Reduction in Brushless Wound Rotor Vernier Machine Using Third-Harmonic Multi-Layer Winding

This article aims to realize the brushless operation of a wound rotor vernier machine (WRVM) by a third-harmonic field produced through stator auxiliary winding (X). In the conventional model, a third-harmonic current is generated by connecting a 4-pole armature and 12-pole excitation windings serially with a three-phase diode rectifier to develop a pulsating field in the airgap of a machine. However, in the proposed model, the ABC winding is supplied by a three-phase current source inverter, whereas the auxiliary winding (X) carries no current due to an open circuit. The fundamental MMF component developed in the machine airgap creates a four-pole stator field, while the third-harmonic MMF induces the harmonic current in the specialized rotor harmonic winding. The rotor on the other side contains the harmonic and the field windings connected through a full-bridge rectifier. The electromagnetic interaction of the stator and rotor fields generates torque. Due to the open-circuited winding pattern, the proposed machine results in a low torque ripple. A 2D model is designed using JMAG-Designer, and 2D field element analysis (FEA) is carried out to determine the output torque and machine’s efficiency. A comparative performance analysis of both the conventional and proposed topologies is discussed graphically. The quantitative analysis of the proposed topology shows better performance as compared to the recently developed third-harmonic-based brushless WRVM topology in terms of output torque and torque ripples.

Double star permanent magnet synchronous machine: modified direct torque control

In the area of high power drives, double star synchronous machines are an interesting choice compared to conventional synchronous machines, due to the relatively low torque ripple created. In this paper, direct torque control (DTC) of double star permanent magnet synchronous machine (DS-PMSM) using artificial neural networks (ANN) is proposed. MATLAB/Simulink results show the comparison between direct torque control (DTC) and direct torque control using artificial neural networks (ANN). The analysis of the results shows good performance for speed, small torque and flow ripple when using the artificial neural network (ANN) strategy.