Ripple Factor Research Articles

Microstrip Lowpass Filter Realization Using Monic Chebyshev Polynomial

This paper presents a novel approach to microwave lowpass filter design that addresses several challenges in modern microwave systems, including size, performance, and cost. With that in mind, we propose using monic Chebyshev polynomials as the characteristic function for the filter to achieve a low passband insertion loss and maximum cutoff slope. The half-power cutoff frequency characterizes these filters, and the ripple factor is not considered a design parameter. To demonstrate the effectiveness of the monic Chebyshev approximation, a comparison is made with chained function (CF) filters designed for microwave applications. It has been shown that the monic Chebyshev filter outperforms CF filters in all applications, including microwaves.

Topology design of variable speed drive systems for enhancing power quality in industrial grids

In the last two decades, a rapid increase in the utilization of non-linear loads within electrical grids has been observed. Consequently, elevated levels of harmonics are found in both voltage and current waves, and adverse effects on power quality are caused. In this context, the variable speed drive (VSD) systems are considered a significant non-linear contributor. To mitigate the harmonic content in VSD systems, various techniques are explored, such as electronic smoothing inductor incorporation in the DC-link, active filters utilization at the grid side, and passive filters integration. A technique centered on the reconfiguration of the DC-link in the VSD systems is proposed in this paper to improve the overall performance of the VSD systems. The configuration comprises two transistors and two diodes, along with smoothing inductors and a capacitor to enhance power quality in the VSD systems. The utilization of three-stage sine pulse width modulation (SPWM) control technology ensures accurate control of the switches, generating optimal control signals that enhance the power quality of the voltage and current waves at the grid side. The effectiveness of the proposed approach is tested via time-domain simulation in MATLAB/Simulink under both constant and variable loading conditions and is verified using a laboratory prototype. The obtained results demonstrate a notable improvement in power quality, showcasing reduced total harmonic distortion (THD) in AC voltage and current waveforms, as well as minimized ripple factor in the DC-link when compared to existing methods.

Switching regulator based on an adaptive DC-DC buck converter for a lithium-ion battery charging interface

A switching regulator based on an adaptive DC-DC buck converter for a Li-ion battery charging interface is introduced in this paper with the aim of improving the efficiency of charging the Li-ion battery during the whole charging process. By using the battery voltage as feedback, an adaptive reference is generated. This reference is employed by the converter, which is in continuous conduction mode (CCM), to produce a wide adaptive output voltage that closely tracks the battery voltage, intended to serve as the power source for the multimode charging interface. The converter was implemented in a 180 nm complementary metal oxide semiconductor (CMOS) process and simulated using the Cadence Virtuoso tool. With an input voltage of 5 V and a switching frequency selected at 500 kHz, the simulation results show that the converter produces different charging currents for each battery charging mode, and an adaptive output voltage ranging from 2.8 V to 4.38 V, with the current ripple of 38 mA in CC mode and voltage ripple factor less than 1% in constant voltage (CV) mode. The average converter efficiency is 83.5%.

Empowering quadrature mirror filter bank architectures: dynamic-grey wolf optimization approach for elevated filter orders

The present study introduces a revised version of the Grey Wolf Optimization (GWO) algorithm called Dynamic-GWO, which integrates a dynamic parameter adaptation mechanism for population diversity enhancement. This mechanism implements the real-time adjustment of control parameters throughout the optimization procedure. The algorithm's effectiveness is demonstrated by its consistent performance across a variety of intricate benchmark functions. Further, the suggested approach is employed to determine the eminent filter tap coefficients of the Quadrature-Mirror-Filter (QMF) bank that enables the configuration with filter orders of 120 and 150, which have yet to be achieved using existing methods. The uniqueness of the proposed approach lies in its capability to overcome the inherent difficulties associated with higher-order filter design, including increased filter length and computational complexity. The primary objective function is to minimize the algebraic sum of three types of distortion: pass-band error, excess power of stop-band, and squared error of the overall transfer function at the quadrature frequency ω q = π / 2 , which generally occur in the procedure of Near-Perfect-Reconstruction (NPR) QMF bank design. In addition, the measured maximum reconstruction errors are 1.303 × 10 − 15 , 2.93 × 10 − 16 and 2.18 × 10 − 06 dB, and aliasing distortions are A L = 85.80 , 128.49 and 153.52 dB for filter orders N = 100, 120 and 150, correspondingly. The proposed algorithm yields significant improvements with an 86.68% reduction in the ripple factor and a 10.45% increase in attenuation compared to the baseline GWO for filter order 120, underscoring its effectiveness in enhancing filter performance. The observed outcomes indicate that the Dynamic-GWO algorithm consistently surpasses the baseline GWO and other Nature-Inspired Algorithms (NIAs) regarding computational ease and convergence speed.

Optimized and Sustainable PV Water Pumping System with Three-Port Converter, a Case Study: The Al-Kharijah Oasis

Optimized and Sustainable PV Water Pumping System with Three-Port Converter, a Case Study: The Al-Kharijah Oasis

An Analysis of Sliding Mode Speed Controller for a Differential Drive Wheel Mobile Robot

In this study, we present a systematically designed Sliding Mode Speed Controller (SMSC) tailored for motors utilized in a Differential Drive Wheel Mobile Robot (DDWMR). Our analysis delves into the critical parameters of the SMSC, including convergence and reaching rates, alongside simulation configurations such as time step. We concurrently consider metrics like rising time, steady-state error, and control ripple factors to optimize performance. Through comprehensive evaluation across various case studies, we demonstrate the efficacy of the fine-tuned SMSC in enhancing the overall performance of the DDWMR. Our simulation results underscore the significance of meticulous parameter tuning, particularly emphasizing the role of time step settings. We find that a smaller time step mitigates chattering phenomena and improves performance, albeit at the cost of increased computational demands and potentially heightened hardware requirements.

Increasing the Energy Efficiency of Traction Electric Drives of Direct Current

Purpose. The work is aimed at improving the energy efficiency of direct current traction electric drives of electric transport by introducing transistor pulse width converters (PWC) with an optimal switching frequency to minimize total electrical losses in the electric drive. The electrical losses of traction electric drives consist of electrical losses in the armature winding and in the PWC transistors. Methodology. To study the dependence on the switching frequency of transistors, the electrical losses in the armature winding and PWC transistors are divided into two parts: static losses from the direct current component of the current and dynamic losses, i.e., losses in the armature winding from harmonic current components and losses in the transistors from transient switching currents. Since the dynamic electrical losses in transistors increase with increasing frequency and decrease in the armature winding, it is necessary to find the optimal PWC co-mutation frequency at which the total dynamic losses in the traction electric drive will be minimal. The goal of increasing energy efficiency in a traction electric drive is achieved by determining the dependence of dynamic electrical losses in the armature winding on the switching frequency of the PWC and computer modeling of the transistor electric drive. Findings. It is found that the relative dynamic electrical losses in the armature winding in the case of polyharmonic power supply are equal to the square of the armature current ripple coefficient. An algorithm for determining the optimal switching frequency of the PWC is developed: 1) the dependence of dynamic electrical losses on the switching frequency of transistors is determined experimentally on computer models of the motor and PWC; 2) the graph of the dependence of total dynamic electrical losses of the transistor electric drive on the time-tothe point of minimum losses, which corresponds to the optimal frequency value, is determined. Originality. For the first time, the authors obtained an analytical expression for the relative dynamic electrical losses in the armature windings, which are equal to the square of the armature current ripple factor. Practical value. Establishing the optimal switching frequency of the PWC according to the developed methodology reduces electrical losses in traction electric drives, i.e., increases their energy efficiency.

Impact on battery performance with hybrid energy storage: An investigation of rate limiter application

AbstractIntegrating hybrid energy storage system (HESS) consisting of battery and supercapacitor provides balance over the power generation and load demand, ensuring the system's stability under transient conditions. Along with battery storage, to control its rate of charging/discharging a rate limiter (RTL) is usually employed. However, the impact of the RTL on battery storage efficiency and system performance has not been explored in the existing literature. This paper investigates the performance of a grid‐tied photovoltaic (PV) system with HESS under dynamic scenarios with different RTL values applied to the battery storage. The paper explores the simulation analysis considering transient, linear, and steady‐state conditions with varying PV generation and load demand. The simulation study shows that a lower RTL value may slow down the battery response, leading to inefficient utilization of battery storage. Alternatively, a very high RTL value will not appropriately regulate the battery current, which may lead to frequent charging and discharging and deterioration of battery life. For the proposed system, RTL with a value of 100 A/s seems appropriate, providing 1.29 Wh of energy through battery storage with an energy efficiency of 91.81% for the simulated time. The DC voltage is efficiently maintained at 400 V with a ripple factor of 0.45%.

Winding-MMF-based design and investigation of dual-winding hybrid-tooth vernier permanent magnet motor with reduced torque ripple and improved power factor

In this paper, in order to further reduce torque ripple and improve power factor, a new vernier permanent magnet motor is proposed, in which the design concept of dual-winding hybrid-tooth configuration is incorporated. In order to clarify motor torque ripple and power factor, the winding-magnetomotive-force-based design and analysis method is proposed, in which harmonic characteristics are considered as key factors during the magnetic field modulation process. The relationship between harmonics generated by winding MMF, torque ripple, and power factor are investigated. In addition, the split-tooth vernier permanent magnet motor is also investigated as a referenced motor. Detailed comparisons between the DWHT-VPM motor and ST-VPM motor are carried out, including air gap magnetic field, torque, and power factor. Both theoretical and simulation results verify the reasonability of the proposed DWHT-VPM motor, and the effectiveness of the proposed winding-MMF-based analysis method, which provide a new potential research path for the design and analysis of flux modulation motors.

Research on Torque Ripple and Influencing Factors of Hydro-Generator

Background: The safe and stable operation of large-capacity hydro-generators is of great significance to the power grid. However, due to the armature reaction and the stator slots of the hydroelectric generator, the torque ripple of the generator is usually large. Long time running under the condition of large torque ripple will cause damage to the generator components and even threaten the safety of the power grid. Objective: To study the factors affecting the torque ripple of the hydro-generator and reduce the torque ripple. Methods: A 24 MW bulb tubular hydro generator is taken as an example, a two-dimensional transient electromagnetic field model was established, and the correctness of the model was verified by experiments. The causes of armature reaction and cogging effect on motor torque are analyzed. The effects of these two factors on torque ripple are studied respectively. The torque ripple under different working conditions is calculated, and the main factors causing and increasing torque ripple during normal operation of hydro generator are determined. Results: The torque ripple increases approximately linearly with the increase of the 7th and 11th harmonic contents, while it increases nonlinearly with the increase of the 5th harmonic contents. When the excitation current increases from 720 A to 960 A, the torque ripple is increased by 11.4kN•m. In addition, when the excitation current increases from 720A to 840A (Rated excitation current of the generator is 840A), the torque ripple increases greatly, the torque ripple increases by 6.6kN•m. When the excitation current exceeds the rated excitation current, due to the influence of magnetic saturation, the increasing extent of torque ripple gradually decreases. When the excitation current increases from 840A to 960A, the torque ripple increases only by 4.8kN•m. Conclusion: Due to the armature reaction, the harmonic magnetic potential will be generated in the generator, which will affect its torque ripple. The torque ripple of the generator will increase obviously with the increase of harmonic content. When the generator is in no-load operation, the slot effect is the main cause of the torque ripple. In the actual operation of the generator, it usually needs to adjust the excitation current to make the generator meet the requirements of various working conditions.

Study of the lighting characteristics of Uniel retrofit LED lamps

The paper considers the photometric characteristics of LED retrofit lamps produced by the Russian-Chinese company Uniel: Uniel LED-G45-6W/4000K, Uniel LED-A60-8W/6500K, and Uniel LED-A60-9W/4000K, designed to replace traditional incandescent bulbs. During the research, comprehensive measurements of photometric parameters (luminous flux, power consumption, color temperature, color rendering index, ripple factor, power factor) have been carried out and the luminous efficacy has been calculated. The results of the measurements have been presented in relation to the supply voltage. Based on the data obtained, an analysis is carried out of the compliance of the initial measured characteristics of the lamps with the values declared by the manufacturer. The analysis of the emission spectra leads to the conclusion that the Uniel LED-A60-8W/6500K lamps are equipped with white light-emitting diodes, the spectrum of which consists of a blue emission band from the semiconductor crystal with a maximum at ~450 nm and a phosphor band with a maximum at ~560 nm, which converts some of the blue emission from the crystal into long-wavelength spectrum. The emission spectra of the Uniel LED-G45-6W/4000K and Uniel LED-A60-9W/4000K lamps, in addition to the blue emission band from the semiconductor crystal with a maximum at ~450 nm, contain emissions from two phosphors, the bands of which have maxima at ~560 nm (green) and ~630 nm (red), which results in a lower color temperature of the LEDs. The paper also provides a detailed analysis of the light power distribution curves, thermal operating conditions, and structural features of the lamps. The research results lead to the conclusion that it is advisable to recommend Uniel LED-G45-6W/4000K and Uniel LED-A60-9W/4000K lamps for use as light sources to replace traditional incandescent lamps because their photometric characteristics comply with the declared parameters and permissible deviations specified in the regulatory standards.

20-Sim Bondgraph for Solar Home Applications

Designing of solar generation for home applications using MATLAB/sim electronics and Bond Graph model 20- sim used in this paper. The devices required for home applications are solar panel, irradiance and temperature insists as input and generates DC as output to the solar panel. As the solar panels generates DC output but our home requires 240 v AC supply, to convert this DC to AC power electronic device inverter requires. This inverter converts DC to pulsating AC supply. To convert pulsating AC to pure AC needs LC filter. The output DC of solar depends upon temperature and irradiance, no more the temperature is not constant depends on atmosphere varying from morning to evening at afternoon only maximum temperature, high power attains and at morning and evening low temperature, low power attains but any time the home needs constant power supply to the load for 24 hours for this purpose boost converter requires for continuous supply. The device Boost converter is connected between solar panels and inverter. Instead of boost converter the device Transformer can also be used between LC filter and load. The cost of transformer is high and requires more space but in boost converter only inductor, diode, capacitor, one switch uses and obtains continuous supply, reduces the ripple factor. First all the devices solar panel, boost converter, single phase inverter are designed individually and combined by using MATLAB/ sim electronics and Bond Graph 20-sim for both software applications better output waveforms are obtained.

Advanced Iterative Synthesis of Equiripple Dual-Band Filters With Fully Prescribed Performance

In this letter, an iterative method is presented to synthesize equiripple dual-band filters with fully prescribed in-and out-band performance. The synthesis relies on an improved Remez algorithm where respective ripple factors are introduced for the two given passbands. As a result, an equiripple response can be achieved within each passband, and their return loss (RL) (i.e., RL <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$_{1}$</tex-math> </inline-formula> and RL <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$_{2})$</tex-math> </inline-formula> levels can be different and controllable by setting the ratio of the ripple factors. Note that an extra transmission zero (TZ) is thus generated and adjustable based on the RL ratio, whose location is more flexible (to prevent locating inside of a passband) when compared with previous works. To demonstrate the effectiveness of the presented method, we provide and discuss two synthetic examples with various filter functions, and obtain desired results.

Improvement of power quality of a 200 kW grid-connected PV system

&lt;span lang="EN-US"&gt;In order to enhance electricity quality, a grid-connected photovoltaic (PV) system simulation is presented in this study. A 200 kW photovoltaic system is integrated to a utility grid and loads. A 25 kV 3-level insulated gate bipolar transistor (IGBT) bridge converter is used. Through this system integration of a renewable energy source with a non-renewable source is achieved. This system also wins over the intermittent nature of the renewable source (solar energy) and non-reliability of conventional sources (utility grid). Power and signal quality for various signals such as ripple factor and total harmonic distortion has improved. The suggested system is investigated using MATLAB/Simulink environment. Total harmonic distortion (THD) in voltage and current, ripple factor correction is also incorporate in the MATLAB model.&lt;/span&gt;

Flow Ripple Reduction in Reciprocating Pumps by Multi-Phase Rectification.

Reciprocating piezoelectric micropumps enable miniaturization in microfluidics for lab-on-a-chip applications such as organs-on-chips (OoC). However, achieving a steady flow when using these micropumps is a significant challenge because of flow ripples in the displaced liquid, especially at low frequencies or low flow rates (<50 µL/min). Although dampers are widely used for reducing ripples in a flow, their efficiency depends on the driving frequency of the pump. Here, we investigated multi-phase rectification as an approach to minimize ripples at low flow rates by connecting piezoelectric micropumps in parallel. The efficiency in ripple reduction was evaluated with an increasing number (n) of pumps connected in parallel, each actuated by an alternating voltage waveform with a phase difference of 2π/n (called multi-phase rectification) at a chosen frequency. We introduce a fluidic ripple factor (RFfl.), which is the ratio of the root mean square (RMS) value of the fluctuations present in the rectified output to the average fluctuation-free value of the discharge flow, as a metric to express the quality of the flow. The fluidic ripple factor was reduced by more than 90% by using three-phase rectification when compared to one-phase rectification in the 2-60 μL/min flow rate range. Analytical equations to estimate the fluidic ripple factor for a chosen number of pumps connected in parallel are presented, and we experimentally confirmed up to four pumps. The analysis shown can be used to design a frequency-independent multi-phase fluid rectifier to the desired ripple level in a flow for reciprocating pumps.

Assessment of Converter Performance in Hybrid AC-DC Power System under Optimal Power Flow with Minimum Number of DC Link Control Variables

This paper presents a strategy to evaluate the performances of converter stations under the optimized operating points of hybrid AC-DC power systems with a reduced number of DC link variables. Compared to previous works reported with five DC-side control variables (CVs), the uniqueness of the presented optimal power flow (OPF) formulation lies within the selection of only two DC-side control variables (CVs), such as the inverter voltage and current in the DC link, apart from the conventional AC-side variables. Previous research has mainly been focused on optimizing hybrid power system performance through OPF-based formulations, but has mostly ignored the associated converter performances. Hence, in this study, converter performance, in terms of ripple and harmonics in DC voltage and AC current and the utilization of the converter infrastructure, is evaluated. The minimization of active power loss is taken as an objective function, and the problem is solved for a modified IEEE 30 bus system using a recently developed and very efficient Archimedes optimization algorithm (AOA). Case studies are performed to assess the efficacy of the presented OPF model in power systems, as well as converter performance. Furthermore, the results are extended to assess the applicability of the proposed model to the allocation of photovoltaic (PV)-type distributed generations (DGs) in hybrid AC-DC systems. The average improvement in power loss is found to be around 7.5% compared to the reported results. Furthermore, an approximate 10% improvement in converter power factor and an approximate 50% reduction in ripple factor are achieved.

BLDC motor torque ripple factor lowering and FOPID based motion control using DGOA algorithm

The Brushless Direct Current (BLDC) motor has many benefits due to characteristics like its small size and precise speed regulation. Uncertainty problems are presented by the system’s slow Proportional-Integral (PI) controller response time as well as some BLDC motor operating circumstances. The proposed Fractional-Order Proportional-Integral-Derivative (FOPID) controller and Difference of Orientation Offset Gaussian (DOOG) Grasshopper Optimization Algorithm (GOA) (DGOA) function are used to mitigate torque ripples in BLDC motors and overcome these drawbacks. An adaptive parameter has been introduced to enhance the performance of the conventional GOA method, and the performance of the suggested DGOA is compared to the benchmark functions. The simulation of the driver with the suggested DGOA-FOPID results in an improvement in Torque Ripple Reduction and speed control is obtained that better torque ripple reduction and speed regulation have been achieved.

Electric vehicles charging station configuration with closed loop control

&lt;p&gt;&lt;span lang="EN-US"&gt;Recently, the demand for electric vehicles (EV) has been on the rise in global markets due to the orientation of national policies to reduce emissions and global warming through the electrification of the transportation sector and the use of clean energy sources. Electric vehicles function on batteries, which must be recharged, either by slow charging at home or by fast charging with a direct current. In the fast-charging process, the batteries can be charged in less than 15 minutes. In this paper, an off-board charger with a three-phase, six-pulse voltage rectifier was designed using the MATLAB/Simulink program. The closed control circuit was simulated, where the simulation results were influenced by changes to the input voltage. When the input voltage was increased or decreased by 5%, this control maintained the value of the current and voltage at the output to be equal to the reference values required to achieve fast charging. The simulation results showed that in the first case where no filter was used, the output voltage and current had a high amount of ripple that exceeded the permissible value. Therefore, a low-pass filter was designed to reduce the ripple factor to a value that was within the permissible limit.&lt;/span&gt;&lt;/p&gt;

Asymmetric Winding Structure for Concentrated Winding Permanent Magnet Motors to Achieve a Low Torque Ripple and High Slot Fill Factor

Asymmetric Winding Structure for Concentrated Winding Permanent Magnet Motors to Achieve a Low Torque Ripple and High Slot Fill Factor

Compact Broadband Optical Polarizers Based on the Multiple-Defect Photonic Crystals

In order to design an optical polarizer, the linear birefringence effect of uniaxial anisotropic materials is utilized to break the degeneracy of the TM and TE resonances in a defected one-dimensional photonic crystal. A broadband performance is achieved by introducing and engineering the multiple-defect structures. Consequently, compact broadband TM mode polarizers are proposed and numerically analyzed to demonstrate the good performance in the long-wavelength communication band (C-band). A <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$6.7~\mu \text{m}$ </tex-math></inline-formula> long double-defect polarizer is proposed with polarization extinction ratio (PER) greater than 27.27 dB and a ripple-free insertion loss (IL) less than 0.22 dB over an operational bandwidth (BW) of 17 nm. In addition, a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$9.3~\mu \text{m}$ </tex-math></inline-formula> long triple-defect polarizer is designed with PER>31.31 dB, IL< 0.22 dB, and a ripple factor of 2.8% over a wide BW of 34.2 nm.