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This study aims to investigate simultaneous power and thermal loading.

Finite element method simulations coupled with experiments.

The effects of power cycling have been determined.

This paper aims to testify the combined effects of thermal and power cycling loads on the reliability of solder ball joints with barrel- and hourglass-type geometries in an electronic system. The finite element simulation outcomes showed that the maximum strain energy was accumulated at the edges of barrel-type solder, whereas the hourglass-type was vulnerable at the necking side. It was also found that the hourglass-type solder showed a reliable behavior when the sole thermal cycling was exerted to the electronic system, whereas the barrel-type solder was a better choice under simultaneous application of thermal and power loadings. The experimental results also confirmed the finite element simulation and indicated that the solder joint reliability strongly depends on the geometry of interconnection in different operating conditions. An extensive discussion was presented to shed light on the paramount importance of combined thermal/power cycling on the reliability of solder joints.

The purpose of this paper is to present a new method of measuring thermal resistance of power light-emitting diodes (LEDs). Properties of power LEDs strongly depend on their internal temperature. The value of this temperature depends on the cooling conditions characterized by thermal resistance.

The new method of measuring the value of this parameter belongs to the group of electric methods. In this method, the problem of estimating the value of electrical power converted into light is solved. By comparing the values of the case temperature obtained for the LED operating in the forward mode and the reverse-breakdown mode, the thermal power is estimated. On the basis of the measured value of the thermally sensitive parameter (the LED forward voltage) and the estimated value of the thermal power, thermal resistance is calculated.

The elaborated method was used to measure thermal resistance of the selected types of power LEDs operating at different cooling conditions. The correctness of the elaborated measurement method was proved by comparing the results of measurements obtained with the use of the new method and the infrared method.

On the basis of the obtained results of measurements and the catalog data of the tested diodes, the dependence of the measurement error of thermal resistance of the LED on its luminous efficiency is discussed.

The new measurement method is easy to use and more accurate than the classical method of thermal resistance measurement of the diode.

China has proposed two-stage goals of carbon peaking by 2030 and carbon neutralization by 2060. The carbon emission reduction effect of the power industry, especially the thermal power industry, will directly affect the progress of the goal. This paper aims to reveal the spatial-temporal characteristics and influencing factors of carbon emission efficiency of the thermal power industry and proposes policy suggestions for realizing China’s carbon peak and carbon neutralization goals.

This paper evaluates and compares the carbon emission efficiency of the thermal power industry in 29 provinces and regions in China from 2014 to 2019 based on the three-stage slacks-based measure (SBM) of efficiency in data envelopment analysis (DEA) model of undesired output, excluding the influence of environmental factors and random errors.

Empirical results show that during the sample period, the carbon emission efficiency of China’s thermal power industry shows a fluctuating upward trend, and the carbon emission efficiency varies greatly among the provincial regions. The carbon emission efficiency of the interregional thermal power industry presents a pattern of “eastern > central > western,” which is consistent with the level of regional economic development. Environmental factors such as economic level and environmental regulation level are conducive to the improvement of carbon emission efficiency of the thermal power industry, but the proportion of thermal power generation and industrial structure is the opposite.

This paper adopts the three-stage SBM–DEA model of undesired output and takes CO₂ as the undesired output to reveal the spatial-temporal characteristics and influencing factors of carbon emission efficiency in China’s thermal power industry. The results provide a more comprehensive perspective for regional comparative evaluation and influencing factors of carbon emission efficiency in China’s thermal power industry.

This paper aims to measure Chinese regional thermal industries’ evolution.

This paper uses data envelopment analysis (DEA) and global Malmquist–Luenberger productivity (GMLP) index.

The results reveal that the development of Chinese thermal power industry varies significantly in different regions, and it is highly correlated with the level of local economic development. Although the change of technical efficiency and scale efficiency had different impacts on different regions from year to year, the overall GMLP index change shows a close relationship with the contemporaneous frontier shift.

The results indicate that the Chinese Government should make efforts to promote its policy implementations and regulations in thermal industries so that the contemporaneous frontier will shift toward the global technology frontier with more desirable outputs and less undesirable outputs.

As an application, this study uses DEA and GMLP index to measure the productivity of Chinese thermal industries in 30 Chinese provinces from 2006 to 2013. The results have the meaningful policy implications for decision makers in charge of Chinese thermal industries.

This study aims to investigate the effects of thermal–hydro interconnection on the revenues, market value and curtailment of variable renewable energy (VRE). The increasing market shares of VRE sources in the Northern European power system cause declining revenues for VRE producers, because of the merit-order effect. A sparsely studied flexibility measure for mitigating the drop in the VRE market value is increased interconnection between thermal- and hydropower-dominated regions.

A comprehensive partial equilibrium model with a high spatial and temporal resolution is applied for the analysis.

Model simulation results for 2030 show that thermal–hydro interconnection will cause exchange patterns that to a larger extent follow VRE production patterns, causing significantly reduced VRE curtailment. Wind value factors are found to decrease in the hydropower-dominated regions and increase in thermal power-dominated regions. Because of increased average electricity prices in most regions, the revenues are, however, found to increase for all VRE technologies. By only assuming the planned increases in transmission capacity, total VRE revenues are found to increase by 3.3 per cent and VRE electricity generation increases by 3.7 TWh.

The current study is, to the authors' knowledge, the first to analyze the effect of interconnection between thermal- and hydropower-dominated regions on the VRE market value, and the authors conclude that this is a promising flexibility measure for mitigating the value-drop of VRE caused by the merit-order effect. The study results demonstrate the importance of taking the whole power system into consideration when planning future transmission capacity expansions.

The purpose of this paper is to solve economic emission dispatch problem in connection of wind with hydro-thermal units.

The proposed hybrid methodology is the joined execution of both the modified salp swarm optimization algorithm (MSSA) with artificial intelligence technique aided with particle swarm optimization (PSO) technique.

The proposed approach is introduced to figure out the optimal power generated power from the thermal, wind farms and hydro units by minimizing the emission level and cost of generation simultaneously. The best compromise solution of the generation power outputs and related gas emission are subject to the equality and inequality constraints of the system. Here, MSSA is used to generate the optimal combination of thermal generator with the objective of minimum fuel and emission objective function. The proposed method also considers wind speed probability factor via PSO-artificial neural network (ANN) technique and hydro power generation at peak load demand condition to ensure economic utilization.

To validate the advantage of the proposed approach, six- and ten-units thermal systems are studied with fuel and emission cost. For minimizing the fuel and emission cost of the thermal system with the predicted wind speed factor, the proposed approach is used. The proposed approach is actualized in MATLAB/Simulink, and the results are examined with considering generation units and compared with various solution techniques. The comparison reveals the closeness of the proposed approach and proclaims its capability for handling multi-objective optimization problems of power systems.

Power modules including the insulated gate bipolar transistor (IGBT) are widely used in the applications of motor drivers. The thermal behavior of these modules makes it important to choose the optimum design of cooling system. The purpose of this paper is to propose an RC thermal model of the dynamic electro‐thermal behavior of IGBT pulse width modulation inverter modules.

The electrothermal model has been implemented and simulated with a MATLAB simulator and takes into account the thermal influence between the different module chips based on the technique of superposition.

This study has led to a correction of the junction temperature values estimated from the transient thermal impedance of each component operating alone.

In this paper, an experimental technique of a thermal influence evaluation is presented.

This paper aims to present the results of investigations that show the influence of soldering process parameters on the optical and thermal parameters of power LEDs.

The power LEDs were soldered onto metal core printed circuit board (MCPCB) substrates in different soldering ovens: batch and tunnel types, characterized by different thermal profiles. Three types of solder pastes based on Sn99Ag0.3Cu0.7 with the addition of TiO₂ were used. The thermal and optical parameters of the diodes were measured using classical indirect electrical methods. The results of measurements obtained were compared and discussed.

It was shown that the type of oven and soldering thermal profile considerably influence the effectiveness of the removal of heat generated in the LEDs tested. This influence is characterized by thermal resistance changes. The differences between the values of this parameter can exceed 20%. This value also depends on the composition of the soldering paste. The differences between the diodes tested can exceed 15%. It was also shown that the luminous flux emitted by the diode depends on the soldering process used.

The results obtained could be useful for process design engineers for assembling power LEDs for MCPCBs and for designers of solid-state light sources.

This paper presents the results of investigations into the influence of the soldering profiles and soldering pastes used on the effectiveness of the removal of heat generated in power LEDs. It shows and discusses how the factors mentioned above influence the thermal resistance of the LEDs and optical parameters that characterize the light emitted.

The purpose of this paper is to measure technical efficiency of Indian thermal power sector employing the recent by-production approach.

The by-production approach is used in conjunction with data from the Central Electricity Authority (CEA) of India to compute the output-based Färe, Grosskopf, Lovell (FGL) efficiency index and its decomposition into productive and environmental efficiency indexes for the ITPPs

The authors show that given the aggregated nature of data on coal reported by CEA, CEA’s computation of CO₂ emissions through a deterministic linear formula that does not distinguish between different coal types and the tiny share of oil in coal-based power plants, the computed output-based environmental efficiency indexes are no longer informative. Meaningful measurement of environmental efficiency using CEA data is possible only along the dimension of the coal input. Productive efficiency is positively associated with the engineering concept of thermodynamic/energy efficiency and is also high for power plants with high operating availabilities reflecting better management and O&M practices. Both these factors are high for private and centrally owned as opposed to state-owned power-generating companies. The example of Sipat demonstrates the importance of (ultra)supercritical technologies in increasing productive and thermodynamic efficiencies of the ITPPs, while also reducing CO₂ emitted per unit of the net electricity generated.

This paper uses the by-production approach for the first time to measure technical efficiency of ITPPs and highlights how the nature of the Indian data impacts on efficiency measurement.

The purpose of this paper is to present an electrothermal model of the module containing power light emitting diodes (LEDs) situated on a common base.

The electrothermal model of this device, which takes into account both self-heating and mutual thermal coupling between the diodes situated in this module, is described.

The correctness of the presented model is verified experimentally, and a good agreement of the calculated and measured optical and thermal characteristics of the considered module is obtained.

The presented model can be used for different structures of the LED module, but electrical inertia in the diodes is omitted.

The presented model was used to calculate electrical, thermal and optical waveforms of the module OSPR3XW1 containing three power LED situated on the common base.

The presented model takes into account thermal inertia in the considered LED module and its cooling systems with mutual thermal coupling between all the diodes situated in the same module.