Power Dissipation Loss Research Articles

A novel development of a new single switch inductor coupled DC-DC converter for PV system with two-leg inverter

From the power generation history, the nonrenewable power sources utilization is falling extremely because of their demerits are high atmospheric pollution, more expensive, more catchment area for development, high fossil fuel transportation cost, less flexibility, and reliability. So, the sunlight systems are utilized in this work for feeding the power to the central grid. On the earth, the sunlight energy availability is more and it is more flexible for the installation. However, the sunlight photovoltaic (PV) module’s power production is very low. To improve the power generation of the PV network, a modified slider maximum power point tracking (MPPT) controller is proposed in the first objective and it is interfaced with the sunlight system for capturing more sunlight insolation thereby moving the functioning point of the solar system from local MPP place to required global MPP place. The features of this sliding controller are continuous peak power production, easy development, less power dissipation losses, plus good dynamic system response. In the second objective, the available voltage of the PV is low which improved from low level to high level by utilizing the Wide voltage supply-inductor coupled converter. The development of this circuit needed very less inductive, plus capacitive components. Also, it is developed by selecting a single switch. As a result, the entire network power production cost is reduced. In the third objective, a two-leg inverter is proposed for the transformation of the DC voltage supply into three-phase powers. The MATLAB/Simulink tool is used to investigate the overall system.

Single Diode Solar Cells-Improved Model and Exact Current-Voltage Analytical Solution Based on Lambert's W Function.

There are three standard equivalent circuit models of solar cells in the literature—single-diode, double-diode, and triple-diode models. In this paper, first, a modified version of the single diode model, called the Improved Single Diode Model (ISDM), is presented. This modification is realized by adding resistance in series with the diode to enable better power loss dissipation representation. Second, the mathematical expression for the current–voltage relation of this circuit is derived in terms of Lambert’s W function and solved by using the special trans function theory. Third, a novel hybrid algorithm for solar cell parameters estimation is proposed. The proposed algorithm, called SA-MRFO, is used for the parameter estimation of the standard single diode and improved single diode models. The proposed model’s accuracy and the proposed algorithm’s efficiency are tested on a standard RTC France solar cell and SOLAREX module MSX 60. Furthermore, the experimental verification of the proposed circuit and the proposed solar cell parameter estimation algorithm on a solar laboratory module is also realized. Based on all the results obtained, it is shown that the proposed circuit significantly improves current–voltage solar cell representation in comparison with the standard single diode model and many results in the literature on the double diode and triple diode models. Additionally, it is shown that the proposed algorithm is effective and outperforms many literature algorithms in terms of accuracy and convergence speed.

Symmetric hybridised design for a novel step‐up 19‐level inverter

Nowadays, reduction in number of dc voltage sources alongside boosting property of the output voltage with reduced circuit components are counted as the most important topological features for the new structures of multilevel voltage source inverters. Considering the above, this study presents a new configuration of such converters which can produce a step-up 19-level waveform of the output voltage with a contribution of only two same (symmetric) values of dc voltage sources and 12 power switches. The proposed structure is composed of a switched-capacitor (SC) and a floating-capacitor-based (FCB) cell integrated into two isolated sub-units that have been series with each other as an hybridised platform. Herein, the relevant involved switches of the SC and FCB sub-units are modulated on the basis of an hybridised pulse width modulation technique which facilitates a significant degradation in the total power loss dissipation. An appropriate boosting feature with a self-charge balancing capability of all integrated capacitors, reasonable number of required semiconductor devices, higher efficiency and less complexity are other advantages of the proposed step-up 19-level inverter. To verify the precise performance of the proposed topology under different types of loading conditions, apart from the theoretical analysis, several simulation and experimental results will also be presented.

Cascaded multilevel inverter using series connection of novel capacitor‐based units with minimum switch count

This paper presents a new family of cascaded multilevel inverters (CMLIs) which can generate a considerable number of output voltage levels with minimum number of required accompanying switching devices. Conceptually, each stage of proposed CMLI is composed of using a novel capacitor-based unit including two floating capacitors, one embedded dc voltage source and three power switches. In this case, the balanced voltage of integrated capacitors can be precisely provided as self-voltage balancing without using any auxiliary circuits, close loop systems and intricate modulation techniques. In addition, to reach different number of output voltage levels, four different algorithms pertaining to the symmetrical, binary asymmetrical, trinary asymmetrical and also hybrid patterns for determining the magnitude of isolated dc voltage sources are presented. Hereby, proposed hybrid structure is capable of working under mixed switching frequency without aiming the conventional full H-Bridge cell. Therefore, a high quality of output waveforms with reduced switching devices as well as power loss dissipation can be alternatively achieved. To confirm the validity of proposed CMLI, a complete comparison with several recently presented topologies besides several simulation and experimental results based on trinary asymmetrical and hybrid evolved structures will be also given.

Investigation on weight consideration of liquid coolant system for power electronics converter in future aircraft

Cooling systems significantly contribute to the total mass and volume of power electronic systems. In the case of aerospace application, it will directly increase the operating cost of the aircraft. This paper experimentally and numerically investigates the weight contribution of the liquid cooling system for power electronics converter in future aircraft. In order to investigate, a cooling system of 2 and 6 pass cold plates is designed and its cooling performance is analyzed. The weight and size contribution is discussed based on available coolants in the aircraft, flow rate ranges from 2 to 8 LPM and 1% to 3% power loss dissipation. Water is added and examined for completeness of the studies. This paper concludes that oil is inappropriate coolant for this particular case. The optimum parameters (Q=8 LPM with 9.5kg pump weight) for most promising coolant (fuel) that give high extraction rate with low weight contribution for the highest density cooling system are indicated.

Space Vector Modulation Controlled Single Phase Five Level Inverter for Fuel Cell Applications

In low power system a single phase converter is usually adopted. This paper deals with five-level Converter topology with SPWM technique. A review of the state of the art of five-level topologies and theoretical power loss comparison with proposed solution is realized. The main characteristics of these modulations are reduced, switching losses, balanced power loss dissipation among the devices with in a cell and among the series connected cells. A Neutral point Clamped type of Multilevel Inverter is more efficient .The proposed converter architecture is based on Single-Phase five-level system for Fuel cell with Polymer Exchange type. In this system, Space Vector Modulation (SVM) technique is used. Simulation and Experimental results show the effectiveness of the proposed solution.

Magnetic hyperthermia of laponite based ferrofluid

Magnetic Hyperthermia experiments have been performed on different concentrations of magnetic iron oxide nanoparticles immobilized on nano-clay disks. The specific absorption rate (SAR) was measured in AC field amplitudes H0 from 7 to 30kA/m. At low field amplitudes, SAR followed the usual H02 law whereas for higher field amplitudes a linear dependence was found for the higher concentrations. Measurements at three different field amplitudes were also performed for a wide range of iron oxide concentrations in order to determine the effect of the Brownian relaxation time to SAR. A field dependent maximum was observed and for fields up to 20kA/m the power dissipation losses were well explained according to theoretical predictions.

Efficient Sequential Switching Hybrid-Modulation Techniques for Cascaded Multilevel Inverters

This paper presents four different sequential switching hybrid-modulation strategies and compared for cascaded multilevel inverters. Hybrid-modulation strategies represent combinations of fundamental-frequency modulation and multilevel sinusoidal-modulation (MSPWM) strategies, and are designed for performance of the well-known alternative phase opposition disposition, phase-shifted carrier, carrier-based space-vector modulation, and single-carrier sinusoidal-modulations. The main characteristic of these modulations are the reduction of switching losses with good harmonic performance, balanced power loss dissipation among the devices with in a cell, and among the series-connected cells. MSPWM and its base modulator design are implemented on a TMS320F2407 digital signal processor (DSP). Complex programmable logic device realizes hybrid-modulation algorithm with base pulsewidth modulation (PWM) circulation, and is integrated with DSP for sequential switching hybrid PWM generation. The proposed modulations can be easily extended to three phase, and higher level inverters, operates with same physical structure of the power module. The feasibility of these hybrid modulations are verified through spectral analysis, power loss analysis, simulation, and experimental results.

Recent Developments in Fault Detection and Power Loss Estimation of Electrolytic Capacitors

This paper proposes a comparative study of current-controlled hysteresis and pulsewidth modulation (PWM) techniques, and their influence upon power loss dissipation in a power-factor controller (PFC) output filtering capacitors. First, theoretical calculation of low-frequency and high-frequency components of the capacitor current is presented in the two cases, as well as the total harmonic distortion of the source current. Second, we prove that the methods already used to determine the capacitor power losses are not accurate because of the capacitor model chosen. In fact, a new electric equivalent scheme of electrolytic capacitors is determined using genetic algorithms. This model, characterized by frequency-independent parameters, redraws with accuracy the capacitor behavior for large frequency and temperature ranges. Thereby, the new capacitor model is integrated into the converter, and then, software simulation is carried out to determine the power losses for both control techniques. Due to this model, the <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">equivalent series resistance</i> (ESR) increase at high frequencies due to the skin effect is taken into account. Finally, for hysteresis and PWM controls, we suggest a method to determine the value of the series resistance and the remaining time to failure, based on the measurement of the output ripple voltage at steady-state and transient-state converter working.

Commercial Frequency AC to High Frequency AC Converter With Boost-Active Clamp Bridge Single Stage ZVS-PWM Inverter

This paper presents a novel soft-switching pulsewidth modulation (PWM) utility frequency ac to high frequency (HF) ac power conversion circuit incorporating boost-active clamp single stage inverter topology. This power converter is more suitable and acceptable for cost effective HF consumer induction heating applications. Its operating principle is presented using the switching mode equivalent circuits in addition to the operating voltage and current waveforms. The operating performances of this high frequency inverter using the latest insulated gate bipolar transistors are illustrated, which includes HFAC power regulation ranges and actual efficiency characteristics based on zero voltage soft switching operation ranges and the power dissipation loss analysis as compared with those of the previously developed high frequency inverter. In addition, a dual mode selected control scheme of this high frequency inverter based on a constant frequency asymmetrical PWM and pulse density modulation control scheme is discussed in this paper in order to extend the soft switching operation ranges and to improve the power conversion efficiency at the low power settings. The practical effectiveness of this power frequency converter is substantially proved on the basis of experimental results from practical design example.

Slow wave vane structure with elliptical cross-section slots: an analysis

Mathematical analysis of the wave equation in cylinders with elliptical cross-section slots was performed. Compared to slow wave structures with rectangular slots higher impedance and lower power dissipation losses are evident below a certain value of kh. These features could lead to improved designs of traveling wave magnetrons and gigahertz backward-wave oscillators as well as linear traveling wave tubes with relatively shallow slots.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>