Low Ripple Research Articles

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.

Fuzzy logic controller-based Luo converter for light electric vehicles

<p>A brushless DC motor (BLDC) drive fed by a Luo converter is presented in this paper for the use in electric vehicle (EV) applications. The proposed Luo converter provides stable and ripple free output for EV. An approach for getting the stable output voltage is by using a fuzzy logic controller to control the Luo converter. It helps to generate the appropriate pulse with respect to the feedback voltage. This proposed system has the advantages like voltage increase, high-gain output with low ripples and high efficiency. The performance of this proposed drive is tested through hardware prototype at varying line voltage levels and results are demonstrated. A comparative analysis is presented to justify the effectiveness of the proposed Luo converter fed EV motor.</p>

An Enhanced Model Predictive Direct Torque Control of SRM Drive Based on a Novel Modified Switching Strategy for Low Torque Ripple

An Enhanced Model Predictive Direct Torque Control of SRM Drive Based on a Novel Modified Switching Strategy for Low Torque Ripple

A Low Ripple and Fast Transient Response Charge Pump in CMOS Image Sensors

A Low Ripple and Fast Transient Response Charge Pump in CMOS Image Sensors

Wind Energy Conversion System using Cascading H-Bridge Multilevel Inverter in High Ripple Scenario

This paper presents wind energy conversion system using CHB MLI and phase interleaved boost converter to overcome high voltage and current ripple. Developments in power electronics technology have a direct impact on advances in wind energy conversion systems. WECS output voltage may fluctuate depending on wind speed. For WECS to maintain a constant output voltage, a power converter is required. This paper explains how to configure a phase-interleaved boost converter and voltage controller to maintain a stable intermediate circuit voltage in the system. The proposed cascading H-bridge multilevel inverter (CHB MLI) converts DC/AC using a novel topology. Separate DC sources are not utilizing the suggested topology. Multi-level inverters are operated by specific harmonic disposal pulse width modulation, or SHE-PWM are utilized. PMSG voltage, CHB-MLI voltage, boost converter voltage and rotor speed have seven different levels of simulated waveforms. Among the many advantages of three-phase alternating DC-DC boost converters, that are high efficiency, fast dynamics and very low current ripple. The output voltage is increased to 400 V using a three-phase interleaving converter, which also maintains a higher efficiency of about 98%. DC-DC power converters have proven to be essential components of many applications and topologies. The interleaving technique is necessary to address the main disadvantages of DC-DC power converters: increased voltage, reduced efficiency, and rippled current. Interleaved boost converters have several advantages, including lower switching losses, lower voltage and current ripple, increased efficiency, and more. To improve the converter's overall functionality, the "n" parallel converter is connected through an interleaved boost converter. This paper presents a performance analysis of a multiphase alternating boost converter to reduce high voltage and current ripple. MATLAB/Simulink is used for analysis and simulation of phase-interleaved boost converters.

Design and Fabrication of Switched Reluctance Motor for Energy Efficient Operation by Minimizing Torque Ripple

Around the world, motor is consuming more than 40% of the total-generated electrical energy. Accordingly, energy efficient electrical drives are the needs of the hour. The Switched Reluctance Motor (SRM) is more energy efficient than other kinds. Since SRM has a rugged structure, it has inherent fault tolerance characteristics and is cost-effective than synchronous and induction machines. Nevertheless, the application of such a motor is limited due to low torque density, torque ripples and power losses because of control circuit. In this research work, the author proposed a novel-designed SRM, which is achieved by optimizing stator and rotor pole arc. Alongside, a novel control circuit, which has single transistor, is proposed. The modification of stator and rotor pole arcs assists in the reduction of the torque ripple. The stator pole arc is modified from 32 degree to 36 degree, and the rotor pole arc is modified from 30 degree to 28 degree. Thus, the torque ripple is reduced from 3.25 to 2.92 Nm, and thus, the useful torque is increased from 4.94 to 5.2 Nm. Furthermore, a single transistor switching device is used instead of the conventional one with four switches. Hence, energy loss on the control circuit is significantly reduced. From the experimental analysis, it is found that, with-pole-arc modified SRM has higher efficiency than the one without it.

A Comprehensive Review on the Power Supply System of Hydrogen Production Electrolyzers for Future Integrated Energy Systems

Hydrogen energy is regarded as an ideal solution for addressing climate change issues and an indispensable part of future integrated energy systems. The most environmentally friendly hydrogen production method remains water electrolysis, where the electrolyzer constructs the physical interface between electrical energy and hydrogen energy. However, few articles have reviewed the electrolyzer from the perspective of power supply topology and control. This review is the first to discuss the positioning of the electrolyzer power supply in the future integrated energy system. The electrolyzer is reviewed from the perspective of the electrolysis method, the market, and the electrical interface modelling, reflecting the requirement of the electrolyzer for power supply. Various electrolyzer power supply topologies are studied and reviewed. Although the most widely used topology in the current hydrogen production industry is still single-stage AC/DC, the interleaved parallel LLC topology constructed by wideband gap power semiconductors and controlled by the zero-voltage switching algorithm has broad application prospects because of its advantages of high power density, high efficiency, fault tolerance, and low current ripple. Taking into account the development trend of the EL power supply, a hierarchical control framework is proposed as it can manage the operation performance of the power supply itself, the electrolyzer, the hydrogen energy domain, and the entire integrated energy system.

A new transformerless buck‐boost converter with improved voltage gain and continuous input current

AbstractThis paper proposes a new transformerless buck‐boost converter with an extended voltage conversion ratio. This converter has semi‐quadratic voltage gain, which provides more gain with lower duty cycles. This converter has a simple structure and easy implementation, which reduces the cost and increases efficiency. The proposed converter operates in continuous conduction mode and provides two operation modes by turning on and off the switches. The suggested converter has continuous input current and low input current ripple, which is important when utilizing renewable energy sources. The calculation of the proposed converter includes ideal and practical voltage gain, current calculations, voltage stresses of the switches and diodes, current stress of the switches, parameter design, efficiency, and a brief analysis of discontinuous conduction mode and boundary conditions. The proposed converter provides efficiency of about 93.1% in boost mode and 92.14% in buck mode at 50 W output power. The suggested converter varies the input voltage from 20 to 48 V in boost mode and changes the input voltage from 20 to 10.4 V in buck mode. Finally, a laboratory prototype has been built to prove and evaluate the simulation results and theoretical analysis of the proposed converter.

Providing Low Current Ripple and MPPT Requirements in PV Panels with IBC Operating in Critical Current Mode

As energy demand increases, the investment cost of photovoltaic (PV) systems decreases due to mass production. That results the usage of PV panels to become widespread. Changes in environmental conditions result in a change in the power produced by PV panels. Maximum power point tracking (MPPT) is proposed to handle this problem. In addition to changing environmental conditions, the current ripple of the PV panel is another significant problem for the power produced. High current ripples affect the dynamic response of the PV panels and make it difficult to maintain the system to operate at maximum power point. Using an interleaved boost converter (IBC) and driving the converters in critical conduction mode (CRM) is a well-known solution for reducing high current ripple and switching losses in power supplies. In this study, an IBC operating in CRM with MPPT and ensuring low current ripple from the panels is proposed. To verify the theoretical approach, experimental and simulation studies were conducted. A 30 W prototype is designed and tested under various conditions. The MPPT efficiency of the prototype circuit is measured as 98.1%. It has been seen that the real-time and simulation results are in accordance with the theoretical ones.

Ripple analyze and design considerations for an interleaved boost converter (IBC) for a PV source

This paper approaches the interleaved boost converter (IBC) for photovoltaic systems (PVS) with efficiency control. The purpose of this converter is to transfer the low DC PV voltage to a high DC voltage at its output. The low output voltage ripple and especially the low input current ripple (for MPPT) are analyzed, verified and compared to N cell IBCs. To improve the efficiency of the IBC, the control decides how many commutation cells are used, in relation to the actual power. This paper also shows to determine the critical PV current needed to work in continuous conduction mode. Finally, a dual IBC is experimental tested to verify the theoretically approaches.

Development of high-gain switched-capacitor based bi-directional converter for electric vehicle applications

High efficiency, high voltage transfer ratio (VTR), and low input ripple current is required in any bidirectional DC-DC converter (BDC) that plays a major role in interfacing batteries in applications like dc microgrids and electric vehicles (EVs). For meeting these requirements, a switched capacitor-based BDC is proposed to interface the battery with a propulsion system via DC Link. It has a simple circuit with only a set of switching operations, High VTR, and lesser ripple current on the low voltage (LV) side are advantages of the proposed High Gain Switched-Capacitor Bi-directional DC-DC Converter (SC-BDC) making it appropriate for use in EVs. The steady-state analysis, design consideration of passive components, loss and efficiency analysis are presented. Finally, the proposed High Gain SC-BDC is compared with few of the existing BDC in the literature. The feasibility of the converter was demonstrated by simulating a 200 W converter and validating results produced in a MATLAB environment.

A novel vector control strategy for sensorless 3φ induction machines under single‐phase fault

AbstractSafety and reliability are very important in machine driving systems for many industries. A novel rotor flux‐based Vector Control (VC) strategy for Y‐connected 3φ Induction Machines (IMs) without speed sensor under the Single‐Phase Fault (SPF) is proposed. The sensorless VC technique is based on using Asymmetrical Transformation Matrices (ATMs) for stator voltage and current components as well as an Extended Kalman Filter (EKF) for estimation of the speed and d‐q fluxes. Furthermore, a simple model‐based SPF detection mechanism based on the EKF is suggested. The performance of the proposed control scheme for a 1 HP sensorless Y‐connected 3φ IM prototype is validated by several experiments. According to the experimental results, the designed scheme during the SPF has several advantages of improved phase currents and low speed, flux, and torque ripples.

Design and Analysis of a Three-Phase Interleaved DC-DC Boost Converter with an Energy Storage System for a PV System

This paper describes a groundbreaking design of a three-phase interleaved boost converter for PV systems, leveraging parallel-connected conventional boost converters to reduce input current and output voltage ripple while improving the dynamic performance. A distinctive feature of this study is the direct connection of a Li-Ion battery to the DC link, which eliminates the need for an additional charging circuit, which is a departure from conventional approaches. Furthermore, the combination of an MPPT controller and a closed-loop fuzzy controller with a current control mode ensures accurate switching signal generation for all three phases. The meticulously tuned system exhibits a remarkably low ripple content in the output voltage, surpassing calculated values, and demonstrates a superior dynamic performance. The investigation extends to a comprehensive analysis of losses, encompassing inductor copper loss and semiconductor conduction loss. In all scenarios, the converter exhibits an efficiency exceeding 93%, highlighting its robust performance as an effective solution for PV systems.

A New Double-Switch SEPIC-Buck Topology for Renewable Energy Applications

In addition to their conventional use in electric motor drives, DC-DC converters have a variety of other uses, such as energy storage, energy conversion, cyber security systems, uninterruptible power supplies, and renewable energy systems. An innovative DC-DC converter is suggested in this article. Designing a new, high-gain DC-DC converter scheme known as a double-switch SEPIC-buck converter (DSSB) is possible after making some adjustments to the SEPIC converter that is currently known in accordance with accepted techniques. The output voltage magnitude of the proposed converter is either larger than or less than the input voltage magnitude and is the same sign as the input voltage. According to the theoretical and analytical study that has been supported by the real-world application, high voltage gain, low switching stress, and low inductor current ripple are the main characteristics of the proposed DSSB converter. The related small-signal model was also used to build the closed-loop system. The frequency response and output voltage behavior were investigated when the input source voltage abruptly changed as a step function. Based on the comparison study with other DC-DC converters, the DSSB converter outperforms currently known DC-DC converters such as Buck, SEPIC, Boost, Buck-Boost, and other SEPIC converter topologies in terms of voltage gain, harmonic content, normalized current ripple, dynamic performance, and efficiency. Additionally, the frequency response and control of the proposed converter using an alternate current (AC), small-signal, analysis-based, current-mode control technique are both provided. Thus, the DSSB is regarded as safe in overcurrent situations because of the small-signal analysis with the current control strategy. As a result of the verification of the proposed control technique, the resistance to changes in the DSSB parameters, improved dynamic performance, and higher control accuracy are further advantages of current-mode control based on small-signal analysis over other control approaches (PI controllers). Finally, the experimental and simulation results from Simplorer 7 and MATLAB/Simulink are used to validate the findings of the analytical and comparative investigation.

Research on low frequency ripple suppression technology of inverter based on model prediction

Research on low frequency ripple suppression technology of inverter based on model prediction

AISHa: an ECRIS for nuclear-physics, new clinical protocols and material experiments

The Advanced Ion Source for Hadrontherapy (AISHa) is an ECR ion source operating at 18 GHz, developed with the aim to produce multiply charged ion beams with low ripple, high stability and reproducibility. Due to its unique peculiarity, it is the most suitable choice for medical applications, but also for nuclear-physics and material experiments. Two sources have been realized: the first at INFN-LNS and the second at the Centro Nazionale di Adroterapia Oncologica (CNAO). The first one, fully commissioned at INFN-LNS, will be used as test-bench for development of new beams and several R&D activities are planned within the IONS experiment to increase plasma confinement and to refine techniques of non-invasive plasma diagnostics to correlate plasma and beam parameters. The second one recently produced the first beam and it will allow to increase the CNAO potential in the field of experimental and industrial research, with the long-term goal of introducing new ionic species into clinical practice such as helium, oxygen and later also iron and lithium, useful for bio-spatial research. In this work, the key peculiarities and the experimental results of the two Aisha ion sources will be presented.

Two-Switch Ultrahigh Step-Up DC–DC Converterer With Low Input Current Ripple and Low Switch Voltage Stress

Two-Switch Ultrahigh Step-Up DC–DC Converterer With Low Input Current Ripple and Low Switch Voltage Stress

Compatible Selective Harmonic Elimination for Three-Phase Four-Wire NPC Inverter with DC-Link Capacitor Voltage Balancing

In this paper a Compatible Selective Harmonic Elimination (CSHE)-PWM is designed for three-leg four-wire (3L/4W) Neutral Point Clamped (NPC) inverter. The proposed CSHE-PWM is capable of eliminating both triplen and non-triplen harmonics from phase voltages and empowers 3L/4W NPC to handle both single/three-phase and linear/nonlinear loads. It has been mathematically proved that DC capacitors self-voltage balancing is achieved thanks to direct control of phase voltage waveform symmetry. Moreover, the cancellation of specified triplen and non-triplen orders has the advantage of having low capacitors voltage ripple. Therefore, the applied technique not only helps removing one leg of the inverter that reduces associate complex calculations and switching losses, but also directly controls phase voltage harmonic profile compared to SHE-PWM for four-leg four-wire (4L/4W) NPC. CSHE-PWM is practically tested on a NPC inverter prototype to validate the efficient harmonic elimination from the phase voltage waveforms along with capacitors voltages balancing under symmetrical/asymmetrical loads.

High Voltage-Gain Common-Ground Three-Port DC-DC Converter With Low Current Ripples on the PV Source for Standalone Applications

High Voltage-Gain Common-Ground Three-Port DC-DC Converter With Low Current Ripples on the PV Source for Standalone Applications

To Design a Pulse Generator for the Solar Power Multi Level Inverter in Over-Modulation Mode

Over modulation (OM) phenomenon has been investigated through several Pulse Width Modulation (PWM) techniques in the Solar Power Multi Level Inverter. However, due to non- linear characteristics and a severe low harmonics ripple, it has not been used in closed-loop control with small power grid connected solar panel however it is beneficial to work in over modulation region to utilize the maximum DC bus voltage in open loop system.