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Power Electronics, Converters, Applications and Design

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... is an integer [10], [11]. The carrier frequency is the frequency of the triangular wave, while the modulation frequency is that of the desired voltage fundamental at the inverter output. ...
... To eliminate the even harmonics at low values of m f , an odd integer number is preferred for m f [10]. In this particular case, the spectral content of the voltage signal at the PWM inverter output will be analyzed for m f = 15. ...
... The order of these harmonics is generally described by the following expressions [10], [11], ...
Article
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The paper analyzes the influence of the number of rotor bars on the stator current spectral content in a three-phase cage induction motor fed by a pulse-width modulated (PWM) inverter. It is shown that each of the higher-order time harmonics in the supply voltage produces space harmonics in a rotating magnetic flux density wave, which results in induced rotor slot harmonics (RSHs) in the stator current spectrum. The conditions for the existence of these space harmonics are identical to those applying to a mains-fed motor. In other words, the number of rotor bars of a mains-fed motor yielding an RSH-free stator current spectrum produces the same stator current spectrum even in case the motor is inverter-fed. Additionally, to minimize the adverse effects of RSHs in the stator current spectrum, one must consider not only the number of rotor bars, but also its relationship with the frequency modulation ratio of the PWM inverter. Analytical predictions are presented to illustrate these results supported both by numerical simulations of the induction motor modelled through the winding function theory and experimentally taking the case a two-pole cage induction machine as a case study.
... Two-level voltage-source inverters (2L-VSIs) are a well-explored technology [2,3,4], being widely used in low-voltage applications. Three-level voltage-source inverters (3L-VSIs) are presented as a new technology for low-voltage and relatively low-power applications [1]. ...
... Amplitude modulation ratio or index (m a ) -Quotient between the peak amplitude of the sinusoidal control signal or reference voltage and the peak amplitude of the triangular signal or carrier wave (generally kept constant), used to generate the switching signals in SPWM [4]. ...
... Frequency modulation ratio or index (m f ) -Quotient between the carrier or switching frequency, f s , and the fundamental frequency, f, in SPWM [4]. ...
Conference Paper
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Voltage-source inverters (VSIs) are widely used to control the speed and torque of three-phase squirrel cage induction motors (IMs), which represent the most important electrical load in industry. Nowadays , different VSI-technologies are commercially available, having different impacts on the performance and reliability of IMs. When compared to the two-level VSIs, the three-level VSIs are typically seen as an expensive solution. However, in some applications, three-level VSIs can lead to significant improvements in the reliability and performance of the IMs, justifying the additional investment from a life-cycle cost perspective. In this paper, the main conclusions of a comparative study between low-power, low-voltage, two-level and three-level VSIs applied to IMs, are presented. This study is based on simulated and experimental results and includes considerations on motor and inverter losses, inverter output voltage wave quality, motor vibrations, motor acoustic noise, motor electrical insulation stress, and bearing currents, considering steady-state operation. Economical considerations are also presented. The outcomes of the presented study are useful for motor users, helping them to decide technically and economically between both analyzed technologies.
... Output voltage is controlled by variation of switching frequency. Hence stabilization of control loop is complex[8][9]. ...
... Similarly, putting Z o =169.3, v=1.37x10 8 and Z L =R mod =5.2x10 3 in the program gives the frequency response of Transmission Line 2 (shown in Figure 83). The data for above three baud rates are detailed in Table 14  An EMI filter is there to supress the common and the differential modenoise from the switching side to input mains. ...
Thesis
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The project illustrates different DC voltage regulation techniques and basics of high voltage DC generation. Different case studies have been taken up for studying switch mode type high voltage DC regulated power supplies. Power circuit of one of the power supplies is modelled in simulation software and the results are compared with those of actual circuit. The project also focuses on the EMI issue of high voltage power supplies causing interruption or even failure of low voltage interfaces connected to power supplies. An approach is taken to design a surge protective arrangement to protect the low voltage electronics from the high voltage transients caused by arcing, earth fault, switching etc. at the high voltage side. The design aims to meet the IEC standard 61000-4-5 specifying voltage levels and wave-forms for surge immunity test.
... Harmonic Injected modulation technique implies the process which involves the injection of a specified harmonic (third or ninth harmonic) into a modulating signal (sine or cosine wave) and the result obtained is sampled or is compared with multi-carrier signals usually triangular waves to produce output pulses with variable widths [3]. Conventionally, an n-level converter always has nlevel output phase voltage, 2n-1 output line voltage and n-1 triangular carrier signals with the same frequency Fc and the same peak-peak amplitude Ac which are usually placed in a way that their frequency bands are close. ...
... If the modulating waveform (reference sinusoidal waveform) is greater than the carrier signal, then the active switching device corresponding to that carrier is switched on. Conversely, if the reference waveform is less than the carrier signal, then the active switching device corresponding to that carrier signal is turned off [3]. The multi-carriers Simulink models for the nlevel inverter are shown in figures 1 to 3. ...
Article
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This paper explores the analysis of third and ninth harmonic injection to the modulation of a multi-level diode clamped converter (DCC) at a varying modulation index. The spectral distributions of the various multi-level waveforms obtained under normal modulation index of 0.8 and over modulation index of 1.15 were presented in this work. The contribution of this paper is rooted in the introduction of ninth harmonic component to higher-levels of diode clamped converters with reference to the existing third order harmonic injected modulation with detailed Simulink models of 3rd, 5th and 9th voltage levels. The analysis and results obtained from this work shows appreciable reduction in the magnitudes of harmonic distortion values thus ensuring optimum and efficient devices performance.
... (a) respectively. For the under modulation ( ≤ 1), the RMS of the fundamental-frequency output voltage is obtained by [13] : ...
... -1 of[13] are as below:Fig. 13shows the harmonic components of the output offgrid voltage obtained from the FFT analysis of Modelica and EMTP solutions for nonideal models. ...
Conference Paper
This paper presents the Electromagnetic Transient (EMT) modeling and simulation of power electronics in Modelica, a declarative equation-based language. In this paper, modeling of switching components such as diodes, insulated-gate bipolar transistors (IGBT) and multi-level converters using ideal and nonideal components are investigated. A three-phase three-level and a single-phase two-level converter with an open-loop controller are simulated in Modelica and EMTP®. The accuracy and performance of simulations are compared using the variable and fixed-step solvers. Analytical solutions are used for verification of results as well.
... Example, in random pulse width modulation scheme, it relies majorly on randomizing the frequency of the carrier waveform in order to allocate the intense energy of the harmonic frequency of the DC-AC converter output voltage in a constricted high frequency range. The vital advantage of this scheme is to mitigate the energy of the harmonics, which in turn will minimize the THD of the DC-AC converter output voltage [3][4][5][6][7][8][9][10]. But, this act definitely will also distress the energy of the basic frequency component by reducing the size of the amplitude that affects the value of waveform. ...
... For the lower band of waveform is (9) So, in positive half cycle, i.e. when the reference current is more than zero: If ; switch ON S3 and S4 ; switch OFF S1 and S2; ...
Article
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This article presents an assessment of total harmonics effects on grid-connected powered inverter using sine-referenced and static-band hysteresis of current controllers. To realize this art, current transducer, static-band and sine-referenced hysteresis current controllers, solar energy source, maximum power point tracker, grid supply and voltage source DC-AC converter are engaged. The system has these features are: (i) Light weight owing to none transformer-less system application (ii) Efficient in injection of power Under static-band hysteresis current controlled fed-back system, at upper and lower bands of 130Vand 50V, a total harmonic distortion, THD of 1.815% and output voltage, vo of 220Vrms (320V peak) were realized whereas in sine-referenced band hysteresis current controlled fed-back system at upper and lower bands of 430V and 340V, a THD of 1.019% and vo of 220Vrms are released. The computer simulations and spectral analyses of the system were presented
... Step-up and step-down DC-DC converters are shown in Figure 2-2. A rigorous discussion of these DC-DC converters is found in [28]. In order to conduct current, the switches in the converters must be forward biased in addition to providing the pulse width modulated signals to the switch gates. ...
... In time domain, In phasor domain, (2)(3)(4)(5)(6)(7)(8) is amplitude modulation ratio and is between 0 and 1. The bidirectional converter together with the sinusoidal PWM consist the half bridge single-phase switch mode converter [28]. Three of the half bridge single-phase converters connected in parallel and with sinusoidal modulation, signals of 120 apart from each other constitute the three-phase switch mode converter, also known as Voltage Source Converter (VSC). ...
Thesis
In present era, attention towards renewable energy resources has been growing due to the ever-growing energy demand and dwindling of fossil fuels reserves. In order to overcome these challenges, offshore energy resources and oil or gas resources integrated with AC power grid is getting popularity and Multi-terminal HVDC would be the more feasible solution for long distance electricity transmission. Power sources such as wind turbine, solar PV and hydro with their intermittent nature and different kind of grid connections namely stiff and weak grids are considered to meet these challenges. The existing different grid connections will affect the grid dynamics as well as steady state response and raise the problem of Control and Protection of MTDC. Therefore, control and protection schemes problems and the related issues must get serious attention. In this thesis, three terminal grid-connected MTDC grid are proposed in PSCAD/EMTDC software based simulation using conventional PQ control and its improved strategy using Active Power Filtering (APF) while considering weak and stiff grids. By using this technique, dynamic stability of grid will be achieved. MTDC is connected through radial configuration of DC Cable. During DC side contingencies, control structure of voltage source converter (VSC) play remarkable role to shape fault current of MTDC. Theoretical analysis of control structure of VSC-MTDC is thoroughly investigated under steady state. However, this analysis is extended to synchronously rotating reference frame, synchronization angle and AC/DC side currents under DC side faults scenario. Besides that, performance comparison has been drawn for different fault locations from each converter and argued its effect on MTDC terminals. These results will contribute to addressing future challenges regarding the Multi-terminal HVDC smart grid.
... The basic step-up converter called boost [5] converter which benefits from the input inductor is the most popular type of the power factor corrector (PFC) circuit. A combination of the boost or buck-boost converter with the flyback converters are used for low power applications (<200W). ...
... The rating of these components is required to guarantee their safe operation during conduction, turn-on, and turn-off. The switch conduction current is found by (5) and the diode current is calculated by (6). VDC-link is the DC-link voltage at the output capacitor. ...
... can be written as follows [112]. The simulated circuit can be seen in Figure 4.28 ,and the parameters used for the simulation are presented in Table 4.9. ...
... (b) The equivalent circuit. (c) Real transformer built by adding some components to the coupled inductors model adapted from[112]. ...
Thesis
Wide band-gap (WBG) devices enable power converter designs at higher frequency, power density, and efficiency, as compared to silicon-based converters. The coexistence for SiC (Silicon Carbide) and GaN (Gallium Nitride) devices in the ranges 600-900 V motivates a specific study of these components and the development of methods to perform better selection relying on the application, particularly for automotive applications. The proposed methodology starts with static and dynamic tests performed on SiC and GaN devices to validate their models. GaN power devices allow the building of the most integrated converters. Here, an instrumented PCB (Printed Circuit Board) is developed to measure and estimate switching losses including the measurement points needed for this purpose. The parasitic elements of the PCB layout extracted by ANSYS Q3D and the measurement instrument models are also included in the simulation model. Thus, by means of an experimentally validated model, it will be possible to evaluate the total losses in an optimized circuit without probes. Meanwhile, for SiC devices, an evaluation board is used, and an estimating method for inductance parasitic extraction is performed. The switching loss estimation is an important step for power converter design. Moreover, the consequences of faster switching on the gate driver design and board layout generate new challenges for WBG-based converters. An accurate switching loss estimation is a helpful step because it allows for the adjustment of different circuit layouts based on the simulation results. However, the instrumented PCB does not predict the switching losses in an optimized converter, but only on the instrumented PCB. The simulation enables the prediction of switching losses in more realistic converters. Finally, a simulation for each target device (SiC and GaN) is developed considering the main parasitic elements and the measurement instrument models. Thus, the switching losses are computed and compared to experimental results. Since the whole system is validated, to compare the SiC and GaN devices for automotive applications, an optimized DC-DC converter simulation is used for comparing each device under different operation points of the converter.
... [26] offers a topology for a change of magnitude DC-DC converter, achieving terribly high DC voltage stepping ratios and MW-level power transfer. Furthermore, the converter was updated in [27] to allow power reversal and to function in step-down mode. ...
Article
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The shift of the world in the past two decades towards renewable energy (RES), due to the continuously decreasing fossil fuel reserves and its bad impact on the environment, attracted researchers all around the world to improve the efficiency of RES and eliminate problems that arise at the point of common coupling (PCC). Harmonics and un-balance in 3-phase voltages because of dynamic and nonlinear loads cause lagging power factor due to inductive load, active power losses, and instability at the point of common coupling. This also happens due to a lack of system inertia in micro-grids. Passive filters are used to eliminate harmonics at both the electrical converter’s input and output side and improve the system’s power factor. A Synchronous Reference Frame (SRF) control method is used to overcome the problem related to grid synchronization. The sine pulse width modulation (SPWM) technique provides gating signals to the switches of the multilevel inverter. An artificial neural network (ANN) is used at the output of a system to minimize mean square error (MSE) by removing the errors between target voltages and reference voltages produced at the output of a trained ANN. Simulations were done using MATLAB Simulink to highlight the significance of the proposed research study. The simulation results show that our proposed intelligent control scheme used for suppression of harmonics and compensate reactive power more effectively than the SRF-based control methods. The simulation based results confirms that the proposed ANN based harmonic and reactive power control technique performs 0.752 better in terms of MAE, 0.52 for the case of MSE, and 0.222 when evaluating based on the RMSE.
... The behavior of the boost converter is characterized by the actions of its switch, where two modes of operation are specified according to the switch state [48]. Hence, the model of the boost converter according to the state-space representation can be formulated as [3] x = Ax + Bu, ...
Article
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In this paper, a comparative review for maximum power point tracking (MPPT) techniques based on model predictive control (MPC) is presented in the first part. Generally, the implementation methods of MPPT-based MPC can be categorized into the fixed switching technique and the variable switching one. On one side, the fixed switching method uses a digital observer for the photovoltaic (PV) model to predict the optimal control parameter (voltage or current). Later, this parameter is compared with the measured value, and a proportional–integral (PI) controller is employed to get the duty cycle command. On the other side, the variable switching algorithm relies on the discrete-time model of the utilized converter to generate the switching signal without the need for modulators. In this regard, new perspectives are inspired by the MPC technique to implement both methods (fixed and variable switching), where a simple procedure is used to eliminate the PI controller in the fixed switching method. Furthermore, a direct realization technique for the variable switching method is suggested, in which the discretization of the converter’s model is not required. This, in turn, simplifies the application of MPPT-based MPC to other converters. Furthermore, a reduced sensor count is accomplished. All conventional and proposed methods are compared using experimental results under different static and dynamic operating conditions.
... Thus, at low speeds it is important to find the cut-off point where electric braking should be disengaged (Heydari et al., 2019). At "high speeds", the braking effectiveness is strongly affected because of the electric motor limits which reflects in too low torques that further decrease as the speed increase (Mohan et al., 2003). ...
Preprint
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Development of an MPC strategy for regenerative braking in (TTR) hybridized electric vehicles
... A voltage source converter (VSC) is the main interconnection device for distributed generators (DGs) and energy storage systems. According to their topologies, VSCs are categorized into two-level VSCs [3], cascaded multilevel converters [4], diodeclamped VSCs [5], flying capacitor converters [4], and MMCs [6]. Among them, an MMC provides modular and scalable structures which can satisfy any voltage requirements. ...
Article
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This paper presents a novel method for current control for a modular multilevel converter (MMC). The proposed current control methodology is based on a modified sliding mode control (SMC) with proportional and integral (PI) sliding surface which allows fast transient responses and improves the robustness of the MMC control performance. As the proposed method is derived via Lyapunov direct method, the closed-loop stability is ensured and results in globally asymptotically stable. Furthermore, the reaching time is also guaranteed by the proposed method, leading to fast transient responses. The proposed method is validated by comparing with some existing methods, which are proportional integral controller and conventional SMC, via offline and hardware-in-loop (HIL) simulations where a 10 MW, medium-voltage MMC system is tested. According to these results, the proposed method is able to provide fast transient responses, zero overshoot, and robustness to the weak grid and short-circuit conditions.
... To the best of the authors' knowledge, an approach similar to the one presented for load balancing in DC-microgrids considering sources, which considers (i) varied concave non-increasing PWL VI-characteristic curves, (ii) the losses in DCC's, the internal resistances and the cables, (iii) while maintaining an output voltage within a desired range and (iv) catering to a current demand, has not been discussed in literature. [4] [5], [6], [7], [1], [2] , [8] II. THE OPTIMIZATION PROBLEM ...
Preprint
A problem of load balancing in isolated DC microgrids is considered in this paper. Here, a DC load is fed by multiple heterogenous DC sources, each of which is connected to the load via a boost converter. The gains of the DCC's provide for a means to control the division of load current amongst the DC sources. The primary objective of the control scheme is to minimise the total losses in the network, while maintaining the output voltage within a desired range, serving the load current demand and adhering to VI-characteristics of the power sources. Under assumptions of concavity/monotonocity/piece-wise-linearity of the VI-characteristics, the problem is solved using a convex relaxation. It is shown that the solution to the relaxed problem is tight. Thus, the resulting algorithm is guaranteed to reach global optimality in a numerically efficient manner. Simulations are provided for corroboration.
... In AC motor drives, employing sinusoidal PWM (SPWM), discontinuous PWM (DPWM), or SVPWM if the modulation index, M i , is less than or equal to unity, the ratio of the carrier frequency to the fundamental output frequency is recommended to be greater than 21 in the literature [33,34] for an acceptable THD in motor currents. In this application, the operating stator frequency changes from 0 to 155 Hz, as given in Table 3. ...
Article
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The design and development of a high-performance 165 kVA, 750 V DC all-silicon carbide (SiC) traction converter for new generation light rail transportation systems (LRTSs) are described. In the design of the traction motor drive, the efficiency of the overall system is maximized and the line current harmonic content of the traction motor is minimized. A complete mathematical model of the physical system is derived to carry out real-time simulations and proper control of the LRTS on a real rail track. The electrical and thermal performances of traction-type SiC power MOSFET modules are compared with those of alternative hybrid and Si-IGBT modules for various switching frequencies. The implementation of the developed system is also described. The performance of the resulting system is verified experimentally on a full-scale physical simulator as well as for various track conditions. Very promising results for the next generation railway traction motor drives have been obtained in terms of performance criteria, such as very high efficiency, low harmonic distortion of the motor line current, low cooling requirement, relatively high switching frequency, and hence, superior controller performance. The effects of the SiC power MOSFET operation on the insulation of the available traction motors are also examined experimentally. This paper is accompanied by a video demonstrating the experimental work.
... High energy-efficiency, compactness, and the ability to convert a given voltage into any desired output voltage are the key features that make switch-mode power supplies dominant in the field of portable devices. SMPSs are used in a range of low power density applications where buck, boost, and buck-boost converters are used, to the high power density applications where push-pull, half-bridge, and full-bridge versions are used [8]. ...
Article
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With the introduction of switch-mode power supplies (SMPS) in the mid-1970s, the efficiency of DC–DC conversion rose from 60 to 80% and SMPS became a popular power supply solution. However, linear regulators have not become obsolete. The modern power management system in portable devices supports a complex mix of DC–DC converters, combining switch-mode power supplies (SMPS), switched capacitor converters (SCCs), and linear regulators in the form of low-dropout regulators (LDOs). LDOs are used to supply low-voltage DC power rails with very low noise and high current slew rate capability, which are usually fed by the output rail of SMPS. This paper provides a comprehensive review of the evolution of the application scope of linear-type DC–DC converters in the power supply context and the present research trends. First, we review the context of linear DC–DC converters in detail, particularly in portable device power supplies. Then, the details of LDO regulators and their recent industry development and research trends are discussed. Then, the discussion focuses on supercapacitor-assisted low-dropout (SCALDO) regulator design and its scope in the portable device power management together with SCALDO-based dual output and reduced switch designs, and finally, the conclusions follow.
... In Figure 5a, the constrained terminal voltage, V b , is the fixed fundamental per-phase voltage on the AC side of the diode rectifier. Due to the diode rectifier, the passive system will always operate at a unity displacement power factor [21], i.e., I s and V b are in phase. For simplification, it was further assumed that R st in (1) and Figure 5a is negligible. ...
Article
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Small-scale uncontrolled passive wind generator systems are an attractive solution for rural energy generation because of the system’s reliability and low cost. However, designing these uncontrolled wind generators for good power matching with the wind turbine is challenging and often requires external impedance matching. In this paper, permanent magnet generators with different stator and rotor structures were investigated and designed to increase the generator’s synchronous inductance for a natural impedance matching. For the design methodology, multi-objective optimisation was used to design the generators for near-maximum turbine power matching, whereby internal impedance matching was reached as much as possible. It was shown that altering the placement and orientation of the permanent magnets in the rotor is a viable method to achieve the desired impedance matching; however, these generators do not have the best performance. It was found that the surface-mounted permanent magnet generator with semi-closed slots was the optimum topology. An optimised generator prototype was tested for the experimental validation. All designs were verified by comparing the results of 2D and 3D finite-element analysis.
... If the driving power is to be provided by DC motors, a DC-DC converter is needed (Zenk, 2018c). These DC-DC converters are buck (Zenk, 2018d), boost (Rashid, 2017), buck-boost (Zenk, 2017), forward (Mohan et al., 2003), flyback (Zenk, 2018e), zeta (Zenk, 2018f), push-pull (Zenk, 2016a), Cuk (Zenk and Akpinar, 2014) or SEPIC (Zenk, 2016b). It can be provided with type converters. ...
... Thus, at low speeds it is important to find the cut-off point where electric braking should be disengaged (Heydari et al., 2019). At "high speeds", the braking effectiveness is strongly affected because of the electric motor limits which reflects in too low torques that further decrease as the speed increase (Mohan et al., 2003). ...
Article
Regenerative braking is an established technique that can improve the driving range of vehicles with full-electric or hybrid/hybridized powertrain, thus promoting their large-scale adoption. In this paper, the design of an MPC strategy for maximizing regenerative braking in a real vehicle that has been hybridized by means of a kit is presented. The kit is entirely built by the partners of the European Horizon2020 LIFE-SAVE (Solar Aided Vehicle Electrification – LIFE16 ENV/IT/000442) funded project, and features two in-wheel-motors placed on the rear axle, PV panels installed on the roof and the bonnet and a battery pack placed in the trunk. The proposed MPC strategy will serve as a baseline for the implementation of an additional algorithm to the actual version of the hybridized powertrain control such that the new kit will endow the vehicle also with regenerative braking. Since the kit cannot access the vehicle’s ECU in order to avoid code infringements, the MPC relies only on information that can be retrieved via the vehicle’s CAN. In addition to the maximization of the energy recovery during braking, the proposed strategy considers aspects such as the in-wheel-motors non-ideal efficiency and rated specifications, the constraints given by the brake operating region and possible comfort requirements that have a positive impact on the driver’s experience. Furthermore, it also includes a penalty term to force the controller to trade-off with possible high-efficiency operations. The simulation outcomes show the effectiveness of the proposed MPC strategy, enabling the recovery up to approximately 18% of the vehicle’s kinetic energy, and suggest that it can be fruitfully used as a baseline for an additional regenerative braking algorithm to be implemented onto the real vehicle.
... Moreover, for a sinusoidal form of D, the output voltage will have sinusoidal form. Different modulation shames can be used to generate sinusoidal waveforms as discussed in [36]. DC to AC converters known as inverters are employed to convert the direct current voltage to the alternating current. ...
... The system changes states as the switch turns on and off [58,59]. An average model of the system given by (15) and (16) can be obtained by using averaging theory [60]. ...
Article
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The move towards a greener energy mix to fight climate change propels investments in converter-interfaced resources such as wind and photovoltaics, energy storage systems and electric vehicles. The ongoing evolution of the power system is occurring at a very fast pace, challenging transmission and distribution system operators to seek solutions that are not only adequate for this moment but also for future scenarios. Ongoing research in the fields of power electronics, power systems and control aims at developing control strategies that will help the energy transition to occur, while keeping a stable, secure and reliable power system. The objective of this paper is to present a critical review of the control strategies developed for grid-connected power converters found in renewable energy systems, energy storage systems and electric vehicles. The impact of grid-connected converters on the stability of power grids is also reviewed, highlighting the promising control strategies for enhancing system stability.
... Example of IGBT transistor structure, cross-section silicon section, (a) layers in a semiconductor in a transistor, (b) equivalent circuit drawing based on[17,18]. ...
Article
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The article presents the results of tests related to failure analysis and finding ways to diagnose used semiconductor elements, among others, in power electronics converter systems on vessels and offshore facilities (drilling and production rigs and wind turbines). Diagnostic relationships were found between the temperature change in the above systems and the signals generated in the form of elastic waves of acoustic emission. The authors confirmed the influence of the transistor’s working temperature on its amplitude-frequency spectrum of acoustic emission signals emitted. The range of ‘safe temperatures’ was considered which means temperatures that do not directly affect the damage of the component.
Conference Paper
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Many researches were realized for the robotics command in order to ensure the tracking of a desired reference trajectory. This current work concentrates on computed torque controller for robotic manipulator system by applying the linear and nonlinear control to ensure the position tracking. Indeed, the approach conventional control was applied to control a nonlinear dynamic system in order to displace the terminal organ of manipulator arm of an initial position towards any desired destination. The linear control allow us to linearize our system around a fixed point so-called an equilibrium point. Then, the application of the nonlinear control allows widening the application field. Simulations are presented to show the performance of the conventional control to guarantee the boundedness of the outputs robotic systems.
Conference Paper
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Le présent travail portera sur les nouvelles exigences techniques pour l'intégration des sources d'énergie renouvelable éolienne et photovoltaïques au réseau électrique public. Ces exigences techniques ont pour but de définir les conditions de raccordement pour les installations produisant des énergies renouvelables en respectant les contraintes de la sécurité du système qui ne doit pas être détériorée du fait d'un raccordement d'installations produisant des énergies renouvelables toute en minimisant le coût de production des énergies renouvelables et qui ne doit pas subir des hausses déraisonnables. Notre travail consiste à révéler les concepts généraux d'exigences de code de réseau qui peuvent être classées en six concepts tel que le réglage puissance active-fréquence, réglage puissance réactive-Tension, contrôle de facteur de puissance, Capacité Fault Ride Through (FRT) et le concept de protection. Mots clés Energie renouvelables EnR, code réseau, énergie réactive, tension, fréquence et FRT.
Chapter
Power electronic converters find widespread applications in the present times. However, they have been known to be rich sources of electromagnetic emissions. The converters are required to operate in compliance with their electromagnetic environment, for which they must adhere to emission limits imposed by the standards. The power converters are duly tested, and their emission levels are measured and checked for compliance. Therefore, understanding the emission mechanism is necessary to design a power converter that will satisfy the EMC requirements. In addition to the switches, parasitic elements, which are invariably present in every circuit, play a crucial role, especially in the higher frequency range, in degrading the EMC performance of converters. The present chapter takes up these aspects and discusses the reasons behind emissions and the roles played by switch characteristics and parasitic elements. Demonstrations through simulations and computations are presented all along with the discussions, and inferences are accordingly drawn. Finally, the standard specifications for emission measurements and analysis through measuring EMI receiver are briefly introduced. A few popular methods to reduce emissions are demonstrated. The final improvement in the EMI performance is shown with the help of EMI receiver output, in accordance with the CISPR standards.
Article
This paper presents a non‐isolated high step‐up buck–boost with a coupled inductor DC–DC converter relevant for distributed photovoltaic (PV) generation systems. The proposed topology can reach high voltage gain through the combination of a buck–boost converter with a coupled inductor. The configuration of the proposed converter allows to achieve a natural voltage clamp circuit for the switch, recovering the energy stored in the leakage inductance of the coupled inductor. Moreover, the converter allows soft‐switching conditions, that is, Zero Current Switching (ZCS) for the diodes and nearly ZCS for the active switch. Also, the proposed converter presents a low component count and common ground connection of the input and output. The proposed converter is evaluated theoretically by the principle of operation in continuous‐conduction mode (CCM) and discontinuous‐conduction mode (DCM), voltage gain derivation, external characteristics, semiconductor voltage stress, current stress, and design guidelines. Finally, a 650‐W, 36/380‐V, 50‐kHz prototype was built in the laboratory to experimentally evaluate the proposed converter, which reached a maximum efficiency rate of 96.58%. This paper presents a non‐isolated high step‐up buck–boost with a coupled inductor DC–DC converter relevant for distributed PV generation systems. The configuration of the proposed converter allows to achieve a natural voltage clamp circuit for the switch, recovering the energy stored in the leakage inductance of the coupled inductor. Moreover, the converter allows soft switching conditions, that is, zero current switching (ZCS) for the diodes and nearly ZCS for the active switch.
Article
This paper presents a project method of the direct-current link necessary to decouple the rectification and inversion stages present in power electronics converters applied at Subsea Power System. The proposed methodology considers different aspects, such as topologies in the front-end and the back-end converters, its characteristic harmonics, the control strategies for both converters and the dynamical behavior of the load. The calculation memories of each capacitor, designed to be used in Variable Speed Drives that drive the subsea loads, are presented. The subsea power system was modeled with the PSCAD/EMTDC electromagnetic transient software to observe the influence of harmonics on the subsea power system and the voltage of the direct-current link. The results show that the proposed method is effective in filtering harmonics and even enhances the dc-link voltage-ripple compensation. Online version: https://rdcu.be/cFDQM
Chapter
Power Electronic Converters (PECs) are one of the essential elements of micro‐grid environment. Power electronic converters mainly process and control the electrical energy which pass through them before delivering to loads/grid. The main objective of this chapter is to give a better understanding of the basic power converters operation, their design and usage in different applications in micro‐grid environment. Microgrid structure from PECs point of view is presented and necessity of PEC is given in detail. Various power electronic converters which are divided into different subsections (like DC‐DC, DC‐AC, AC‐DC and AC‐AC) based on their input and output type are presented. A detailed explanation of different converters, how they are derived, the basic equations describing them, analytical waveforms, along with suitable applications related to them are presented. In addition to this, various simulation tools available to simulate the power electronic converters will be discussed in this chapter.
Chapter
Electric vehicles are a new and upcoming technology in the transportation and power sector. The US Energy Information Administration states that the world has an adequate crude oil supply until about 2050. Basically, electric vehicles are expected to enter the world market such that by 2030, they will make up 10% of the vehicles being used. The most expensive part of an electric vehicle is the battery, and its charging and maintenance need to be taken care of. The major challenges while adopting EVs as an alternative to the fuel vehicles are the charging problems as it varies from one charger to another. Since the advent of electric vehicles, the need for electric chargers and new techniques for a sustainable solution has grown tremendously. The dead batteries are now getting replaced by the charging batteries. In this paper, we have attempted to improve the performance of the electric vehicle chargers by designing and simulating the same on the MATLAB. For this work, three converters, i.e. buck–boost converter, Cuk converter and Sepic converter, have been considered and designed using different methods such as PWM techniques, using PID and by implementing fuzzy logic techniques. The results have been compared, showing an improvement in their performance all of which has been reported in this paper.
Article
Being an electrical switch, this converter transforms an uncontrolled input DC voltage into a regulated one to get a desired output voltage. The MOSFET works in the circuit boost-converter as an electronic switch that closes and opens several times. The current passing through the inductor determines the modes operation of the boost-converter circuit. We proposed the new fuzzy control circuit (maximum power point (MPP) circuit using Fuzzy Logic Control (FLC) algorithm) was designed after replacing the DC source with a photovoltaic (PV) array and the duty cycle (constant) with the FLC and keeping the circuit components same except for the Pulses Width Modulation (PWM) of frequency 3800 Hz. In the full circuit, they controlled the MPP of the PV array through a boost converter and FLC., the relationship between the power and voltage of the PV array was drawn to access the MPP at fixed constant solar irradiance and temperature. The value of the solar irradiance altered during the day from low (in the morning) to high (with a peak at the noon) before being reduced to very low at the sunset. The proves that the FLC algorithm works efficiently to make the power of the PV cell always at the maximum value (MPP). The stability of the PV cell voltage and its current change also proves that it operates according to the specifications of the P-V and I-V characteristics of the PV cell referred to earlier the output voltage was increased because we used a step-up converter (boost converter with FLC). The achievement system is showed to be efficient and robust in improving solar charging and rectifying capacity.
Chapter
In previous chapters we have presented some examples of current control loop implementations, both for single and for three phase voltage source inverters. We have discussed how to design a PI current controller in the continuous time domain and how to turn it into a discrete time, or digital, controller. We also introduced the principles of dead-beat, predictive current control. In all these cases we have seen how the presence of a current control loop actually turns the VSI into a controlled current source with pre-determined speed of response and reference tracking accuracy. Exactly to maximize these parameters, we have also seen how to implement multisampled versions of the above mentioned controllers and measured the performance improvement they can offer.
Chapter
In this chapter we present the possible means for the application to three phase inverters of what we have just seen about digital current control of single-phase VSIs. When the three phase converter is characterized by four wires, i.e., three phases plus neutral, the application is straightforward, since a four wire three phase system is totally equivalent to three independent single phase systems. Of course, this particular situation does not require any further discussion. On the contrary, we need to apply a little more caution when we are dealing with a three phase system with insulated neutral, i.e., with a three-wire, three-phase system. The objective of this chapter to give the basic knowledge needed to extend the control principles we have previously described to this kind of systems. Two fundamental tools are required to design an efficient three phase current controller: (i) αβ transformation and (ii) space vector modulation (SVM).
Article
In this paper, a new concept based on an integrated hybrid energy system including photovoltaic (PV) and wind turbine (WT) for reactive power support of the grid is presented. Considering the shared grid‐side converter in hybrid energy systems, which is preferably responsible for delivering active power to the grid, the remaining capacity of the converter after providing active power management is utilized as a static synchronous compensator (STATCOM) to overcome the power quality problems in the main grid. For this aim, a new concept named PV‐WT‐STATCOM is proposed, and a flexible control scheme is accordingly designed, which enables a sufficient reactive power compensation in both steady and transient states. The steady‐state issues in the main grid are resolved using the remaining capacity of the shared inverter. In the transient mode, where a large amount of reactive power is probably needed for restoring the grid‐side voltage while the unoccupied capacity of the shared inverter is not sufficient, a new control strategy is developed for reducing the PV's generated power, and providing more unused capacity in the shared inverter. The effectiveness of the proposed configuration in handling reactive power compensation in both steady and transient states are carried out using MATLAB/Simulink. The extensive simulation results in presence of the variable weather conditions confirm that the proposed concept is properly able to improve grid‐side power factor and voltage in steady and transient modes, respectively, without requiring any additional STATCOM. A new concept based on an integrated hybrid energy systems including photovoltaic (PV) and wind turbine (WT) for reactive power support of the grid is presented. Considering the shared grid‐side converter in the hybrid energy systems, which is preferably responsible for delivering active power to the grid, the remained capacity of the converter after providing active power management is utilized as a static synchronous compensator (STATCOM) to overcome the power quality problems in the main grid.
Article
Full-text available
This paper addresses the important role of the flyback or freewheel diodes in the protection of electronic circuits as well as their impact on the transient response of these circuits. Sample case studies are presented and analyzed in the time domain using the software Mathematica (Version12.1). Without any loss of generality, a delayed step-voltage source starting at the time point 2 seconds and a single diode are assumed. The transient response of the investigated circuits is mathematically formulated by a set of differential and algebraic equations with zero initial conditions. They follow Kirchhoff's current and voltage laws. The unit-step function ia approximated within the computer code in terms of the inverse tangent function. The presented results of the program illustrate, among other quantities, the node voltages, the voltage across and the current through the free wheel diode as well as the currents flowing through the other circuit branches. For the sake of clarity, they are also illustrated graphically over the time range between zero and 5 seconds. Their sensitivities to changes in the numerical values of the circuit parameters are demonstrated and discussed. The results are validated through the comparison with the corresponding voltage and current plots published elsewhere in the literature. INTRODUCTION Flyback or freewheel diodes refer to diodes that are inversely parallel-connected across the ends of energy storage elements such as coils and relays. They have an important protective role in the electronic circuits, if a voltage or current changes suddenly, [3,5,7]. Moreover, when using this type of diodes, the rate of change in the circuit current can be reduced in order to avoid the occurrence of voltage spikes. With regard to full wave rectifiers, for instance, a freewheel diode can reduce the harmonics, the sparking and the arcing across the mechanical switch. In other words, it reduces the voltage spikes appearing in inductive loads.
Chapter
The aim of this work is to implement the proposed DC-DC isolated converter on a half brick-sized printed circuit broad (PCB), which is achieved in the hardware by using a planar inductor and planar transformer. Current-fed push–pull converter consists of a pre-regulated buck converter stage where the wide range of input is regulated. The inductor of the buck stage acts as current source to the push–pull converter stage. The buck converter output which is pre-regulated is fed as input to the push–pull converter. Here the buck stage switches operate at 300 kHz, and push–pull stage switches operate at half frequency of the buck stage, to reduce filter size of converter. The output obtained is low voltage and high current. Also, in the circuit, synchronous rectification is used to achieve high efficiency. The proposed converter is hardware implemented to validate the design results.
Chapter
Accumulation of dust in conjugation with various environmental adversities over the surface of PV modules causes soiling phenomenon, thereby generating shading scenarios and leading to reduced irradiance available to the module. Soiling has been recorded as one of the most common detrimental factors to module health and energy output. An overview on the soiling phenomena has been discussed in this manuscript, with a brief discussion regarding the soiling of bifacial PV modules. Furthermore, a case study investigating the impact of bifacial gain of a 90° bifacial PV module installed over two different orientations East–West (E–W) and North–South (N–S) has been conducted. The results show that the performance ratio (PR) of soiled system installed at E–W orientation (1.37) is greater than PR of N–S-oriented system (0.99). The bifacial gain of a soiled system under E–W orientation (0.81) is greater than the bifacial gain of soiled system (0.34) under N–S orientation due to higher irradiance collection throughout the day.
Article
Grid-forming (GFM) converter aims to enforce the voltage and frequency at its terminals in grid-connected and islanded microgrid scenarios. The generalized closed control (GCC) scheme is a well-known solution to achieve this objective, composed of a single-loop voltage control with embedded virtual impedance. Although originally proposed to operate in converters with LC filters at their output terminals, GFM converters that operate with LCL filters have been reported in the literature. The objective of this paper is to analyze the GCC scheme in GFM converters with LCL filters. To this end, the step-by-step design procedure for the damping virtual impedance is presented. In addition, the virtual impedance also allows the design of the voltage controller gains by approximating the plant to be controlled by a first-order system. Three well-known design methodologies for resonant controllers are also compared in the proposed scheme. The results obtained validate the virtual impedance design method and summarize the differences between the design methods for resonant controllers.
Chapter
The energy storage systems (ESS) integrated microgrid have grown attention and acceptance because it has power reliability and sustainable energy utilization capability. Several ESS has been introduced with significant characteristics such as performance, size, life cycle, charging/discharging, safety, reliability, capacity, and cost. This chapter comprehensively reviews the types of ESS technologies, configurations, classifications, features, energy conversion, life cycle, and advantages and disadvantages. Moreover, the power electronics converter interfacing the microgrid has also been briefly studied. The present review critically demonstrates the interfacing circuits of ESS to microgrids. The mathematical modeling of bidirectional DC‐DC converter interfacing the ESS to DC microgrid is presented developed. Moreover, the modeling and control of VSI interfacing the BESS to a three‐phase grid is also demonstrated. The simulation model for both systems is also developed in MATLAB‐Simulink. A critical review of the obtained simulation results is presented to show the ability of the DC‐DC converter and VSI system for charging the BESS and delivering the power to the microgrid as per the requirement assigned by the higher‐level controller of the microgrid.
Article
High step‐up DC‐DC converters are commonly used in new energy applications such as DC microgrid, photovoltaic cell, and fuel cell. Thus, this article introduces a new nonisolated high step‐up DC‐DC converter based on active switched coupled inductor with a voltage multiplier cell. The proposed converter presents low current and voltage stress across the switches owing of the dual active switches structure. Besides that, by the voltage multiplier cell (one diode and one capacitor), the voltage gain of proposed converter is increased. In addition, it can be highlighted that the proposed converter has low component count, simplicity of operation in continuous and discontinuous conduction mode, and energy stored in the leakage inductor that is recycled in the capacitor of voltage multiplier cell. This article discussed the principle of operation, the ideal and nonideal voltage gain, external characteristic, voltage and current stress, design guidelines, and performance comparison with previous high step‐up converters. Finally, a prototype circuit with input power 300 W, input voltage 30 V, and output voltage 400 V was built in the laboratory to verify the theoretical evaluation, and the maximum achieved efficiency was 95.35% at nominal power 300 W. This article introduces a new nonisolated high step‐up DC‐DC converter based on active switched coupled inductor with a voltage multiplier cell. The proposed converter presents low current and voltage stress across the switches owing of the dual active switches structure.
Conference Paper
The method of power factor adjustment serves to offset the impacts of loads which, with a power factor less than one, have an unwanted impact. There are two possible places to implement power factor correction: a utility company may do it to increase the efficiency and stability of the system, or a client may do it at his or her premise. This is vital to guarantee that electricity runs smoothly and costs little over time. An Arduino-based capacitor switching capacitor-assisted power factor adjustment technique has been introduced in this article.
Article
Full-text available
In this paper, a method is proposed to overcome the problem of unconditional switching of relays in a Dump Truck. A Dump Truck has a Relay box containing Relays, which act as an electro-mechanical switch to control various parameters of the Dump Truck. These electro-mechanical switches (Relays) undergo unconditional switching due to mechanical vibrations caused by the uneven terrain of the mining areas. These relays are not soldered, instead they are plugged into the relay base. This is for ease of replacement of a relay if damaged. In some cases, the relay may jump out of its socket due to the vibrations. To overcome this problem, these relays are replaced with solid state power devices such as MOSFETs which are controlled by a Microcontroller.
Chapter
Bereits in Kapitel 3 wurden die Bauelemente der „klassischen“ Leistungselektronik behandelt. Unter dieser soll die Schaltungstechnik, die schon bis ca. 1985 entwickelt wurde, verstanden warden*. Im vorliegenden Kapitel sollen nun neue Bauelemente, die auch bei größeren Leistungen (als seinerzeit bei Transistoren üblich) über das Gate abschaltbar sind, im Detail vorgestellt werden. Dazu kommen weiters neue Technologien (wie Siliziumkarbid bei Dioden) und ergänzende Überlegungen zum Schaltverhalten (z. B. auch für Dioden und Transistoren), sowie neue Schaltungskonzepte.
Devices that can handle voltages in kVs and currents in kAs • ASICs • DSPs • Micro-controllers • FPGA • Integrated and intelligent power modules • Packaging
  • And Potential
AND POTENTIAL ADVANCEMENTS • Devices that can handle voltages in kVs and currents in kAs • ASICs • DSPs • Micro-controllers • FPGA • Integrated and intelligent power modules • Packaging