Switch Mode Power Supply Research Articles

Experimental Lognormal Modeling of Harmonics Power of Switched-Mode Power Supplies

Switched-mode power supplies (SMPSs) are an important component in many electrical systems. As a highly non-linear device, an unavoidable side-effect of SMPS operation is its high harmonics power. One of the ways to model the harmonic power consumption profile is in terms of a random process. This paper addresses random process modeling with a corresponding probability density function (PDF), auto-covariance function (ACF) and spectral coherence. The consumed harmonics power was evaluated under different load conditions and is based on experimental results of current consumption from SMPSs. The analysis shows that harmonics power may be modeled by a lognormal distribution that is time-domain uncorrelated, and that has spectral-domain correlation modeled by a Gaussian radial basis function. Extensive discussion on the modeling results is also provided. Moreover, random simulation approach based on the modeling results was proposed.

Magnetic Signature Reduction by Converter Switching Frequency Modulation in Degaussing Systems

Ships can avoid to be detected by magnetic mines by reducing their magnetic signature with degaussing coils. Degaussing currents are provided by switched mode power supplies which impose a current ripple on top of the degaussing current. The ripple might be visible in the magnetic signature which would increase the detectability of the ship. A way to reduce the ripple in the magnetic field is to use a switching modulation scheme in the degaussing power supplies. In this paper, a magnetic model of a ship with degaussing coils is described. It is used to find the magnitude of the ripple in the magnetic signature. Also the effect of reducing the current ripple by frequency modulation is investigated. Several modulation schemes are modelled. It is found that the ripple in the magnetic signature is often, but not always, negligible due to attenuation by the ship’s hull. For low frequency switching applications, like high temperature superconductor degaussing systems, the ripple is visible in the magnetic signature. It is found that switching frequency modulation is a very effective technique to reduce the ripple of degaussing currents. Of the tested schemes, random lead lag and random switching frequency are the most effective.

Immunity Testing of Mixed Signal Electronics Against Power Supply Disturbances in the Frequency Range From 10 kHz To 5 MHz

A method is presented to test the immunity of mixed signal (digital and analog) electronics to power supply disturbances in the frequency range between 10 kHz and 5 MHz, as those originating from switched mode power supplies. An example of application of the method to a Serializer/Deserializer (SerDes) integrated circuit is illustrated. For these electronic devices the power supply noise can critically affect performance. The SerDes is hosted by an evaluation board supplied by an external Power Module. An ad-hoc disturbance source and Coupling/Decoupling Network (CDN) have been designed to couple a disturbance of significant amplitude to the power supply of the evaluation board while decoupling it from the Power Module. The radiofrequency (RF) impedance of the bypass network of the evaluation board has been considered for the design of both the disturbance source and the CDN. Details about the architecture and operation of the high-current, broadband and linear power amplifier used for disturbance generation are provided, along with component selection and verification of the CDN. The practical implementation of the test, including a feedback control loop capable of generating the specified disturbance level over the frequency range of interest, is described. Finally, test results are reported in terms of the SerDes bit error rate (BER) degradation as a function of disturbance amplitude and frequency.

Variability Caused by Setup and Operating Conditions for Conducted EMI of Switched Mode Power Supplies Over the 2–1000 kHz Interval

The measurement of conducted emissions of switched mode power supplies (SMPSs) is discussed for the 2–1000-kHz frequency range, analyzing variability caused by setup elements and test conditions. The tested SMPSs have 12-VDC output and about 20-W nominal power. They are fed by a controlled ac power supply, instead of mains, through a line impedance stabilization network and various loading levels are applied. Identified causes of variability (supply voltage and frequency variations, thermal stabilization influencing internal mechanisms of emissions) indicate a relevant impact on the spread of measured conducted emissions, ranging from a fraction of decibels to about 10 dB (sample standard deviation). Such phenomena represent a cause first of all of systematic error, but also of increased uncertainty. No EMC standards are known to take them into account, nor the scientific literature reports extensive quantification, as in the present case. The shift of the line spectrum of emission consequential to a mains frequency change revealed to be exploitable also for better identification of internal sources of emission.

Conducted emission simulation and measurement of interleaved DC-DC converters

Switching-Mode Power Supplies (SMPS) are often used to power on-board satellite payloads due to their good conversion efficiency. However, they emit radiated and conducted noise, which can disturb the operation of other payloads. The current ripple sum of the power supplies will appear on the power bus. There are many methods to reduce this summarized noise, one of them is to interleave the on-switching times of the converters. This ripple cancellation method can decrease the noise component on the switching frequency and on its upper harmonics. In this article we are going to demonstrate the effects of the distributed interleaving with a measurement platform consisting of two Pulse Width Modulation (PWM) controlled Buck controllers.

Pulse Bursting Phenomenon in Constant On-time Controlled Boost Converter

Constant on-time (COT) is a pulse frequency modulation based control method, which is widely used for the controller of switching mode power supplies due to the advantages of simple implementation, low cost and good performances. In fact, like hysteretic control, COT is also a ripple-based control, and its loop stability is very dependent on the output voltage ripple characteristic. COT controlled buck converter is mainly concerned in nowadays. For boost converter, the output voltage ripple characteristic is quite different with that of buck converter. Thus, the stability of COT controlled boost converter is necessary to be investigated. In this paper, with particular theoretical analysis, the unique pulse bursting phenomenon in COT controlled boost converter appears when the time constant of the output capacitor is relatively small, which results in large inductor current and output voltage swing. The quantitative relationship between the time constant and the other circuit parameters such as input voltage, output current and inductance is deduced, which is very different with that of COT controlled buck converter. Simulation and ex-perimental results are provided to verify the theoretical analysis results. The investigation presented in this paper gives an im-portant guideline for the circuit parameter design of COT con-trolled boost converter.

Estimate the Meaning-Time-To-Failure of LED driver using Numerical simulation

The Meaning-Time-To-Failure (MTTP), also known as Electromigration Analysis is an estimation of product life. Light-Emitting Diodes (LEDs) are usually driven by constant current switched-mode power supplies, which are invented early than LEDs for lighting applications. While LEDs themselves are extremely reliable and have a long lifetime, the electronic LED drivers in experiment usually fail due to overheating causing Printed Circuit Boards (PCBs) explosion, inability provide current/voltage input to the LEDs over their whole lifetime. This paper proposes a numerical simulation method to predict fault location on PCB of LED driver based on 2-way coupling electro-thermal multiphysic analysis, then applies the analytic models to calculate the time to failure of the points on PCB of LED drivers. The procedures can be applied to assist managers in assessing risk and making LED-based lighting system reliability decisions.

RUL Prediction of Switched Mode Power Supply Using a Kalman Filter Assisted Deep Neural Network

Switched-mode power supply (SMPS) has been of vital importance majorly in power management of industrial equipment with much-improved efficiency and reliability. Given the diverse range on loading and operating conditions of SMPS, several anomalies can occur in the device resulting to over-voltage, overloading, erratic atmospheric conditions, etc. Electrical over-stress (EOS) is one of the commonly used causes of failure among power electronic devices. Since there is a limitation for the SMPS in terms of input voltage and current (two methods of controlling an SMPS), the device has been subjected to an accelerated aging test using EOS. This study presents a two-fold approach to evaluate the overall state of health of SMPS using an integration of extended Kalman filter (EKF) and deep neural network. Firstly, the EKF algorithm would assist in fusing fault features to acquire an comprehensive degradation trend. Secondly, the degradation pattern of the SMPS has been monitored for four different electrical loadings, and a bi-directional long short-term memory (BiLSTM) deep neural network is trained for future predictions. The proposed model provides a unique approach and accuracy in SMPS fault indication with the aid of electrical parameters.

Analysis of supraharmonics in a three-phase frame

Interaction in the supraharmonic range of 1-ϕ device connected in 1-ϕ or 3-ϕ installations will differ according to the design of the installation. Power factor corrected devices employing switched mode power supplies produce supraharmonics in the range 2–150 kHz. The impact of e.g. voltage unbalance, load unbalance and conductor crosstalk on supraharmonics from these devices connected in a 3-ϕ installation are still somewhat unknown. The paper aims to show with measurements and mathematical models the impact of voltage unbalance, load unbalance, and conductor crosstalk on supraharmonics. The impact of voltage unbalance for constant power loads was seen to increase the emission of supraharmonics. Two new terms induced primary and induced secondary emission showing the impact of conductor crosstalk have been introduced. The induced primary emission leads to an increase in the self-emission of the device. The induced secondary emission on the other hand influences the propagation of the emission. The impact of the voltage unbalance, load unbalance, and conductor crosstalk on the addition of supraharmonics emission in the neutral conductor is shown.

МОДЕЛЬ ПЕРЕКЛЮЧАЕМОЙ ШИМ-СТРУКТУРЫ ДЛЯ АНАЛИЗА ИМПУЛЬСНЫХ ПРЕОБРАЗОВАТЕЛЕЙ НАПРЯЖЕНИЯ С ПРОИЗВОЛЬНОЙ ТОПОЛОГИЕЙ

The article considers the problems of analyzing DC-DC voltage converters and analyzes the advantages, disadvantages, as well as the scope of full switched and averaged continuous models of the converters. The feasibility of using the complex of two models (full switch model and averaged continuous model) for analyzing their operation is proved. The general approach to the construction of continuous models of DC-DC voltage converters based on state-space averaging method is considered. Disadvantages of the averaged models using a classic approach are shown. The relevance of the development of universal continuous models of DC-DC converters is substantiated. The possibility of creating such models using averaged models of PWM switching structure included in the DC-DC voltage converter is shown. Analyzed the typical structure of the switch-mode power supply with feedback. An averaged model of the switching structure is proposed, basing on which continuous models of DC-DC converters with any topology can be built. The processes occurring in this switching structure in the mode of continuous and discontinuous choke current are analyzed. A method for constructing continuous models of the main types of DC-DC voltage converters based on switching structure averaged model is proposed. The adequacy of continuous models obtained by this method has been proven. The results of modeling transients on the continuous and full switch models for inverting voltage regulator are demonstrated. The possibility of accounting in the model of active resistances of switches and cumulative choke is shown. The possibility of using the proposed model to obtain the open loop transfer functions is demonstrated, in particular, the characteristics of the duty factor - output voltage. These transfer functions can be used to synthesize control system compensating circuits of the switch-mode power supply. The possibility of using a single generalized averaged model of the switching structure to build continuous models of converters with complex topology using both the Voltage Mode and Current Mode is shown. This creates prerequisites for developing a universal averaged continuous model for DC-DC converter based on this principle

An Integrated Cost-Aware Dual Monitoring Framework for SMPS Switching Device Diagnosis

The ability of a switch-mode AC/DC power supply to shrink supplies is a benefit and a requirement for most electronic devices with limited space. Major failures in switch-mode power supply (SMPS) during adverse working conditions are subject to mostly the switching devices and capacitors. For effective condition monitoring of the SMPS, dual (or multiple) sensing provides a more reliable standpoint against the traditional single sensing techniques as it provides a more comprehensive paradigm for accurate condition monitoring. This study proposes an integrated approach to SMPS condition monitoring by exploiting statistically extracted features from current and voltage signals for system fault diagnosis based on electrical stress. Following a correlation-based feature selection approach, salient features were utilized for improved fault detection and isolation (FDI) using ML-based classifiers. Diagnostic results by the classifiers reveal that the random forest and gradient boosting classifiers are highly reliable but computationally expensive when compared with the others while the decision tree was quite cost-efficient with reliable diagnostic results. The proposed framework is effectively applicable for use in diagnosing the switching devices and classification at different states.

KS IOT Based Automation System to Prevent Crop Vandalization by Rain Water in Agricultural Regions

India’s keystone is Agriculture. Around 70 percent of India’s revenue comes from Agriculture. Conversely the population of India amplifies each and every day which requires efficient and well planned decision making techniques for the production of crops. In this research paper we find the intensification of the structures which prevent destruction of crops due to uneven and heavy rainfall. The goal is achieved by the concept of Embedded System design using IOT technology. This is done automatically without any human interference. Here we first identifies the water level in the agriculture field during rainfall by using water level sensors , if the water level exceeds there limit that will cause spoilage of crop then the device are automatically cover the agriculture field. It also identifies the temperature of the crops by using temperature sensor during the sunny days, if the heat causes spoilage of crops due to intensive sun rays then the device will automatically covers the agriculture field. After covering the agriculture field it will send the alert message using GSM module to the farmer and simultaneously the water of rain is collected through piles that will be reuse later for irrigation. To achieve this we use microcontroller , Solar panels, GSM module, DC motor, sensors, Switched-mode power supply (SMPS), Rechargeable battery

Nonintrusive optimal parameters estimation for a switch mode power supply equivalent circuit model: 120 V 60 Hz CFLs Case study

The large-scale use of home appliances based on Switch Mode Power Supplies (SMPSs) raises the interest in power quality problems they might cause. Accurate modeling of SMPS-based loads allows predicting the collective impact caused on low voltage networks. However, model parameter values for a specific load are not often available. This paper proposes a nonintrusive Optimal Parameter Estimation (OPE) process for an SMPS Equivalent Circuit Model (ECM) through an optimization problem formulation using only current measurements. This OPE process is composed of the Narrow Search (NS) and Data Fitting (DF) methods. The NS method advantage is that it limits the parameter region using datasheets, measurements, and manufacturing standards to obtain optimal parameters for a specific supply voltage. The DF method leading convenience is that it computes the parameters from equations, as a function of nominal voltage and rated power by using data regression. The parameters estimated by the NS method induce errors that exceed about five times the DF method; in addition, the DF method results improve by about 10% methods available in the state-of-the-art. Thereby, the OPE process is helpful in practical applications related to demand-side management or collective harmonic impact for a wide range of SMPS-based loads.

Design and Analysis of Planar Transformers in Modern Switching Mode Power Supply

This paper presents a development and calculated rating of high-frequency transformer connect with switch-mode power supplies. These power supplies are used in various devices such as power personal communications services, television, DVD players and charge mobile phones Thus, increasing power density and decreasing cost are still the main factors in designing a switch-mode power supply. Magnetic elements represent a great amount of size in switch-mode power supplies and therefore volume reduction and power density raise are beneficial. These switch-mode power supplies consist of two power stages separated by a power transformer with high frequency power. The transformer architecture, which can run at a high frequency, has since become a major challenge for the engineers. Lower component height and better thermal management are advantages with the planar core design. This paper provides a detailed summary of the operating principles of high-frequency transformers. Two transformers are compared in a dual active bridge converter: a wire wound, a planar. This paper discusses a comparison between the wire-wound transformer, high-frequency transformer, and structures in terms of winding loss, core loss, leakage inductance, parasitic capacitance the focus of this research is to find an optimal transform solution for the converter operating at a power level of 220 W. Furthermore, the power losses of a planar transformer are estimated.

A design of flyback switched-mode power supply with softswitching using the UC3842 controller

The flyback switched-mode power supply is widely used in various electrical equipments due to its high efficiency and small size. This article is used UC3842 as the core control chip to design a flyback switched-mode power supply. The design includes the input of 36∼48V and an output of 12V and introduces a soft-switching design. The trigger signal of the next cycle arrives after the switching voltage drops to zero and realizes zero voltage switching (ZVS) to reduce switching losses. At the same time, single-ended flyback switching circuits, feedback circuits, and RCD clamp circuits are designed. The simulation result is shown the accuracy for the output voltage is within 1.08%, as well as the ripple factor is below 0.011%.

An Experimental Analysis of Harmonic Distortion Indices In Home Based Electrical Appliances and Improvement Using Passive Filter

Nowadays, the growing use of non-linear loads in home appliances gives rise to harmonic pollution in the electrical power distribution system, which degrades the power quality. Many domestic appliances have power electronic converters that characteristically draw a non-sinusoidal current waveform. Short-term effects of non-linear appliances are causing malfunction and damage of electronic devices and long-term effects are thermal losses in equipment and cable, hasty aging, and reduced life period of devices. The whole impact depends on the power ratings and quantity of electrical appliances and their harmonic diversity. Usually, the existence of harmonics and their effects in a domestic zone are not monitored as compared to the industrial and commercial sectors. To ensure the quality of power, it is necessary that a harmonic study is carried out to identify the details of harmonic pollution that is polluting sources, the parameters or quantities they pollute in each instance, and effective improvement methods. In this paper, experimental analysis was performed which focuses on traditional single-phase home-based electrical appliances causing the quality of power down, and implementation of the passive filter is suggested for improvement in the quality of power. All experimental harmonic distortion measurements of home-based electrical appliances were performed in the power electronic laboratory of QUEST Nawabshah. Harmonic distortion indices measurements of home-based electrical appliances have been taken using the fluke power quality Analyzer (PQA) instrument. The analysis shows that from many types of loads, switch mode power supply (SMPS) based load is rich in harmonic distortion. Therefore, an equivalent model of SMPS load in MATLAB/Simulink is developed to analyze improvement in power quality by designing and implementation of the passive filter. The outcome of this research work will be helpful to make the source current sinusoidal by reducing harmonic distortion and thus improve the power quality.

Improved Power Quality Switched Mode Power Supply Using Buck-Boost Converter

In this work, The devices generally used in industrial, commercial and residential applications need to undergo rectification for their proper functioning and operation. The operation of the buck– boost converter in discontinuous conduction mode ensures inherent PFC operation and reduces complexity in control. Hence there is a need to reduce the line current harmonics so as to improve the power factor of the system. This has led to designing of Power Factor Correction circuits. This concept presents a power factor corrected (PFC) Buck–Boost converter-fed SMPS. This project deals with the design, analysis, simulation, and development of a power-factor-correction (PFC) multiple output switched-mode power supply (SMPS) using a Buck–Boost converter at the front end. Single-phase ac supply is fed to a pair of back-to-back connected buck–boost converters to eliminate the diode bridge rectifier, which results in reduction of conduction losses and power quality improvement at the front end. To observe the performance of this converter, a model based on the Buck Boost topology has been designed and developed software and implemented with Proportional-Integral (PI) and Fuzzy logic controller. The simulations are demonstrated in order to validate the effectiveness of the controllers in power factor improvement. By using MATLAB.

Fuzzy Logic Based Power Factor Correction in Single Phase AC-DC System

In recent years, there has been a significant increase in the number of power electronics converters used in both industrial and home appliances devices. The utilization of electronic ballasts and switching mode power supply in power conservation introduced the trouble of power quality. The currents used by these devices are not sinusoidal and these currents are known as non- linear. Boost type power factor correction (PFC) converters are becoming popular due to their conformity in power system quality problems. Conventionally, power factor correction converters were controlled using Proportional-Integral- Differential (PID) controller to reduce harmonic disturbances and enhance the power factor (PF). Conversely, for non-linear system, their performances are not very acceptable. Because PFC circuit is not linear, in this paper fuzzy logic (FL) controller used to adjust the gain PID controller to improve the performance is presented. It is proposed that when there is fluctuation in the voltage input, the input current should be made by a FL controller. This FL controller has a great effect by keeping the phase angle between current and voltage at a very small value, bringing the PF factor closer to 1.0. This great effect has also been demonstrated in experimental studies. The proposed FL based PFC controller converter is analyzed in MATLAB/Simulink environment under variable loads and different voltages. The Performance results (Total harmonic distortion, PF and efficiency) has been calculated for different input voltage and different loads. The performance results of the FL based PFC is in acceptable ranges.

Suppression Approaches of Far-Field Radiated Emission Using Common-Mode Inductor

The miniaturization and integration of Switching Mode Power Supply (SMPS) is increasing, making it more complicated to analyze and predict its far-field radiated emission, and, consequently, studying the suppression method of far-field radiated emission of SMPS is of practical significance and engineering value. In this paper, a high-frequency SMPS is selected as the research object, whose far-field radiated emission is measured under the condition of three typical suppression methods. The experimental results verified the effectiveness of common-mode inductor and are of reference value for EMC design of power converter. Keywords: SMPS; EMC; Far-field Radiated Emission;

Angle-Based Photovoltaic Curve Tracing using Boost Converter

A photovoltaic (PV) curve tracer is equipment that obtains the characteristic curve of the PV that can be used for PV modelling or performance analysis. Currently, the used of the switched-mode power supply in the PV curve tracer application is limited due to the voltage ripple problem. This paper provides the potential and limitation of designing the PV curve tracer using the boost converter. A new angle-based curve tracing algorithm is proposed to produce evenly distributed tracepoints on the PV curve. The PI controller is used to control the boost converter based on the input from the angle-based curve tracing algorithm. The PV curve tracer is simulated using MATLAB/Simulink. The results show that the proposed PV curve tracer is accurate and trace a significant portion of the PV curve.