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Abstract A 20 kW, 20 kHz high frequency (HF) link maximum power point tracking (MPPT) converter for a grid-connected PV supply, based on all silicon carbide (SiC) power semiconductors, is presented. In the developed converter, SiC power MOSFETs are used in the low-voltage PV panel side and SiC Schottky diodes on the high-voltage DC output, in order to maximize the power conversion efficiency and the power density. Operating principles of the resulting dual H-bridge MPPT converter and the practical aspects of the converter design and its circuit layout, are described in detail. The implemented converter performance is compared with that of a classical Si-IGBT and hybrid-IGBT based MPPT converter in terms of efficiency. This configuration can compete with the non-isolated MPPT converter topologies, such as the boost converter commonly used in grid-connected PV systems, since it allows the possibility of using a conventional two-level, three-phase grid-connected inverter. This is due to the enhanced common-mode EMI performance as compared to non-isolated MPPT topologies, resulting in a competitive high efficiency PV converter design with galvanic isolation. It has been shown that the converter size can be shrinked up to a power density of 1.6 kW/lt, with a DC-DC converter full-load efficiency of 98%. The resulting compact and highly efficient SiC power MOSFET based HF link MPPT converter is suggested to be a part of grid-connected, multi-string PV supplies with simple inverter topologies in the future.

Abstract A 20 kW, 20 kHz high frequency (HF) link maximum power point tracking (MPPT) converter for a grid-connected PV supply, based on all silicon carbide (SiC) power semiconductors, is presented. In the developed converter, SiC power MOSFETs are used in the low-voltage PV panel side and SiC Schottky diodes on the high-voltage DC output, in order to maximize the power conversion efficiency and the power density. Operating principles of the resulting dual H-bridge MPPT converter and the practical aspects of the converter design and its circuit layout, are described in detail. The implemented converter performance is compared with that of a classical Si-IGBT and hybrid-IGBT based MPPT converter in terms of efficiency. This configuration can compete with the non-isolated MPPT converter topologies, such as the boost converter commonly used in grid-connected PV systems, since it allows the possibility of using a conventional two-level, three-phase grid-connected inverter. This is due to the enhanced common-mode EMI performance as compared to non-isolated MPPT topologies, resulting in a competitive high efficiency PV converter design with galvanic isolation. It has been shown that the converter size can be shrinked up to a power density of 1.6 kW/lt, with a DC-DC converter full-load efficiency of 98%. The resulting compact and highly efficient SiC power MOSFET based HF link MPPT converter is suggested to be a part of grid-connected, multi-string PV supplies with simple inverter topologies in the future.

Distribution automation technology plays a key role on power system reliability by providing faster detection, isolating the faulted area and restoring the fault. In this paper, the impacts of distribution automation are considered on radial distribution system in the event of substation transformer bank malfunction at maximum load level with the aim of deferring the big capital investments. The aim of the proposed method is not only to increase physical impact such as the reliability but also to monetize physical measures into significant economic benefits by deferring the overall investment costs. The proposed algorithm is tested with the real distribution system data, and it is shown that it can obtain remarkable economic benefits by deferring the larger capital equipment investments by making smaller investments in distribution automation.

Distribution automation technology plays a key role on power system reliability by providing faster detection, isolating the faulted area and restoring the fault. In this paper, the impacts of distribution automation are considered on radial distribution system in the event of substation transformer bank malfunction at maximum load level with the aim of deferring the big capital investments. The aim of the proposed method is not only to increase physical impact such as the reliability but also to monetize physical measures into significant economic benefits by deferring the overall investment costs. The proposed algorithm is tested with the real distribution system data, and it is shown that it can obtain remarkable economic benefits by deferring the larger capital equipment investments by making smaller investments in distribution automation.

Abstract This paper examines the effects of foreign trade and foreign direct investment (FDI) on CO 2 emissions in Turkey. We consider linear and nonlinear ARDL models and find significant asymmetric effects of exports, imports and FDI on CO 2 emissions per capita. However, FDI has no statistically significant long-run effects. In the long run, decreases in exports reduce CO 2 emissions per capita but increases in exports have no statistically significant effects. Increases in imports push up CO 2 emissions per capita, while decreases in imports have no long-run effects. On the other hand, CO 2 intensity, which measures CO 2 emissions per unit of energy, is not influenced by exports and imports, nor by FDI. Instead, it is affected positively by financial development and urbanization. Also, we find that an environmental Kuznets curve is present for both CO 2 measures so that increases in real GDP per capita have led to reductions in CO 2 emissions for at least the most recent decade, controlling for other confounding factors. Furthermore, the sectoral shares of CO 2 emissions in total CO 2 emissions change asymmetrically with foreign trade for two of four sectors, with export increases leading to lower CO 2 shares and imports having the opposite effect.

Abstract This paper examines the effects of foreign trade and foreign direct investment (FDI) on CO 2 emissions in Turkey. We consider linear and nonlinear ARDL models and find significant asymmetric effects of exports, imports and FDI on CO 2 emissions per capita. However, FDI has no statistically significant long-run effects. In the long run, decreases in exports reduce CO 2 emissions per capita but increases in exports have no statistically significant effects. Increases in imports push up CO 2 emissions per capita, while decreases in imports have no long-run effects. On the other hand, CO 2 intensity, which measures CO 2 emissions per unit of energy, is not influenced by exports and imports, nor by FDI. Instead, it is affected positively by financial development and urbanization. Also, we find that an environmental Kuznets curve is present for both CO 2 measures so that increases in real GDP per capita have led to reductions in CO 2 emissions for at least the most recent decade, controlling for other confounding factors. Furthermore, the sectoral shares of CO 2 emissions in total CO 2 emissions change asymmetrically with foreign trade for two of four sectors, with export increases leading to lower CO 2 shares and imports having the opposite effect.

The aim here is to delay the wearing of hoses and in order to store them and use them in the most efficient way that laying-rallying hoses are dried by decreasing their weight. With this study the objective is decreasing inefficient working hours while saving energy and time. Considering real world conditions, drying hoses are subjected to water absorption for 30, 60 and 90 minutes. Trials are executed in a microwave dryer at 120 W, 350 W and 460 W settings and in a conveyor dryer at temperatures 50 °C, 60 °C and 70 °C. Moisture analysis, strength analysis, drying rate, energy consumption, diffusion coefficient and activation energy calculations were made according to the results obtained. It has been observed that minimum consumption of energy and fastest drying occurred with the power level of 460 W in the microwave dryer. When all of the results are evaluated according to trials, it has been noted that since the mechanisms behind the two dryer systems are not similar and drying times and consumption of energies are different, the microwave dryer is more efficient than the conveyor dryer type.

The aim here is to delay the wearing of hoses and in order to store them and use them in the most efficient way that laying-rallying hoses are dried by decreasing their weight. With this study the objective is decreasing inefficient working hours while saving energy and time. Considering real world conditions, drying hoses are subjected to water absorption for 30, 60 and 90 minutes. Trials are executed in a microwave dryer at 120 W, 350 W and 460 W settings and in a conveyor dryer at temperatures 50 °C, 60 °C and 70 °C. Moisture analysis, strength analysis, drying rate, energy consumption, diffusion coefficient and activation energy calculations were made according to the results obtained. It has been observed that minimum consumption of energy and fastest drying occurred with the power level of 460 W in the microwave dryer. When all of the results are evaluated according to trials, it has been noted that since the mechanisms behind the two dryer systems are not similar and drying times and consumption of energies are different, the microwave dryer is more efficient than the conveyor dryer type.