High-temperature superconductors from the REBCO (RE = rare earth) family have attained industrial production and their performance is continuously being enhanced. However, cabling technology for high-current (kA range) cables for magnet technology is still challenging and there are only few cable concepts available (CORC®, Roebel cable, twisted stack cable). Each of them exhibits different characteristics. In this paper we experimentally investigate CORC® cable produced in-house utilizing a copper tube former. Such a former offers a central cooling channel for partial or complete cable cooling by forced flow of coolant. We focus mainly on AC loss due to transporting AC current, an external applied AC magnetic field and their simultaneous action. In the case of transporting AC current we found indications that a large part of the total loss has its origin in eddy currents due to an axial magnetic field. For the investigation of magnetization AC loss, we prepared several samples with different configurations. In this case we found direct evidence for increasing AC loss due to losses in the metallic former. However, we also found that at low field amplitudes the magnetization AC loss of the complete cable is lower than the loss in the bare former. This is caused by shielding of the magnetic field by a superconductor, which was also confirmed by numerical simulations.
This paper presents a complete model for thermoelectric modules (TEMs) in order to be used in circuit simulations in MATLAB/Simulink software. The purpose of this study is to develop a single block like other circuit elements in the Simulink library by combining both thermoelectric generator (TEG) and thermoelectric cooler (TEC) module parameters and their operations. Since TEG and TEC are both thermoelectric devices, mostly whose main material, such as Bi 2 Te 3 , is the same for similar temperature ranges, a TEG can be operated as TEC and vice versa a TEC can be operated as TEG. In some systems, such as PV-thermoelectric (TE), fuel cell-TE, and battery temperature management of electric vehicles, the modules can be used in both modes. Also, in some cases of these systems, sometimes the TEM may need to be operated as a generator, and sometimes as a cooler. The bidirectional operation of the TEM is a costsaving approach since the 2 types of TEMs are not needed to be installed together. This paper proposes a novel model whereas the studies up to date in the literature have not been fully compatible with the bidirectional usage of the modules. The proposed model deals with the polarities of both the thermal and the electrical ports of the TEM in order to decide the mode of operation, that is TEG or TEC. Maximum parameters and performance parameters for both TEG and TEC operations are included in the module block so as to observe and control the device for desired operating conditions. It is seen that the simulations with the temperature-dependent parameters have given very close results to the graphics of the datasheet. However, simulations in which the Thomson heat isn"t ignored have more deviations compared to the datasheet. Moreover, the simulations with the constant material properties have given better results than the Thomson heat included ones in the cases of the higher ∆T levels. While ∆T is 10 °K, COP max without the Thomson heat has been found as 3.399 which is the same as the datasheet. Meanwhile, COP max with the Thomson heat has been found as 3.7147, and COP max with the constant properties has been found as 3.8057. However; while ∆T is 50 °K, COP max is 0.247 without the Thomson heat which is the same as the datasheet, but COP max is 0.341 with the Thomson heat, and COP max is 0.268 with constant material properties. In addition, it is shown that, under variable polarities of thermal and electrical ports, bidirectional operation of the TEM is successfully achieved and the TEM is operated as both TEG and TEC in the same simulation.
Power systems encounter multiple problems during planning, operating and analyzing processes. Superconducting technologies can be the solution for some of these problems. In this study usage of superconducting cables in the Turkey transmission system are simulated to see the affects. One base and two different cases are discussed. Power flow analysis and voltage stability analysis are done for the real Turkish 22 bus system. The voltage stability is analyzed by using the loading factor. The results show the decrease in losses and the increase of the system's capacity. The amount of CO2 emission is also presented. This study is a rough analyze but a precursor for further studies which will also contain an economical analyze considering the cooling costs and new topology of system.
In this study, in order to reduce the electricity consumption / cost of the Karaman Wastewater Treatment plant, which has the highest flow and electricity consumption in Sakarya, the arrangements that can be made during the working hours of the treatment plant and the generation of electricity by the MHP that can be installed between the outlet of the facility and the discharge point of the wastewater are examined. A change of 17% in the electricity bill costs and up to 50% in the flow rates were observed. Wastewater treatment plant projects keep their capacities high, considering the needs of the next 20-30 years. Based on these results, it is determined that if the electricity consumption amounts in the peak time interval where the unit price of electricity is high is shifted to day and night time zones, the electricity costs of the facilities will decrease. In addition, it has been shown that a part of its own electricity consumption will be met by the micro hydro power plant to be installed between the outlet of the facility and the discharge point.
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