Papers by Keyword: TCR

Abstract: The VN thin films were deposited on glass and Al₂O₃ substrates using reactive magnetron sputtering with a vanadium target in an Ar/N₂ mixed atmosphere. The deposition process was carried out at a substrate temperature of 25 °C and a sputtering power of 250 W. VN thin films were systematically prepared on glass substrates by varying the N₂/(Ar+N₂) ratio to 25%, 33%, 42%, and 56%. The results demonstrated that all as-deposited films consistently exhibited a face-centered cubic (FCC) NaCl-type crystal structure, regardless of the N₂/(Ar+N₂) ratio. Notably, the crystallization phase remained stable even when annealed at temperatures ranging from room temperature to 400 °C. As the nitrogen content increased, the resistivity of the films decreased, and the temperature coefficient of resistance (TCR) shifted toward smaller values. At a nitrogen content of 56%, the film exhibited the lowest resistivity of 63 μΩ-cm, along with a TCR of-460 ppm/°C. Furthermore, the resistivity demonstrated good stability, with only a 3% variation observed over one month.

Abstract: The NbN thin films were deposited onto glass and Al₂O₃ substrates using reactive magnetron sputtering, employing a niobium target sputtered with a mixture of Ar and N₂ gases. The investigation focused on the phase structures, microstructures, and electrical properties of the NbN thin films under various deposition powers and annealing temperatures. The results indicated the presence of a face-centered cubic (FCC) crystal structure in the as-deposited films at a power of 125 W. Interestingly, the crystallization phase remained unchanged within an annealing temperature range from room temperature to 500 °C. It was observed that the resistivity of the NbN thin films increased with higher nitrogen content, while the temperature coefficient of resistance (TCR) showed a tendency towards more negative values as the nitrogen content rose. Notably, at a nitrogen content of 9%, the film exhibited the lowest resistivity of 273 μΩ-cm with a TCR of -240 ppm/°C.

Abstract: A simulation model of 230kV substation primary system and TSC+TCR typed dynamic reactive power compensation control system was constituted with RTDS, and the feasibility of control system with a case was validated. The control system was to monitor the variation of power system equivalent susceptance with sampling the power system voltage, established the relationships between power system susceptance and the firing angle of TCR, adjusted TSC switch and TCR firing angle to dynamically compensate the reactive power of power system. The simulation results demonstrate that the control system can guarantee power system voltage stability and real-time adjust power factor.

Abstract: In this paper, TaN thin film were deposited on ceramic substrates by D.C. magnetron sputtering. The surface morphology of two types of TaN thin film resistors were investigated by SEM. The characteristics of the TaN thin film resistor was also studied. The key point was put on the TCR of the TaN thin film resistors. The resistors were trimmed by the autoxidation process and the anodic oxidation process, and the TCR values of about +21ppm/°C and-137.3ppm/°C in average have been achieved respectively.

Abstract: in practical application of SVC, unbalanced load system exists on many sites, and the voltage at system access point is required to meet the demand of power grid operation. This paper describes a SVC constant voltage control method for an unbalanced load system. the control algorithm controls the voltage at evaluation point to reach the preset range while compensating reactive power of unbalanced load system. the control method could compensate an unbalanced load system into a balanced system, at the same time, the voltage at access point could meet the demand of power grid operation. This control method is particularly applicable to reactive control requirements of steel mills, wind power, solar power grid systems. This algorithm has been applied in Lishizhai 66kV SVC Project in Fushun, inhibits three-phase unbalance of the grid, has achieved good compensation effect.

Abstract: In recent years, as the SVC device have also been used for DC ice melting system, the installment is still on the rise, it is necessary to study the loss situation. This paper firstly analyzed the theory of the loss of its each part of the device, and then finished a simulation based on the PSCAD software. We hope the research can give some value guidance on SVC assembled for the power grid.

Abstract: The cause serious deterioration in power quality problems for the growing impact and nonlinear load capacity, introduced SVC device in the role of modern power systems and applications. According to the lack of adequate regional dynamic reactive power regulation means to cause voltage fluctuations, harmonics exceeded the actual situation, through analysis and simulation of the existing 66kV grid power quality conditions, refers to the necessity of application of SVC, the compensation capacity for SVC, filter capacitor system parameters and control strategies were designed, the results show improved 220kV SVC reactive power flow distribution system, reducing the system once or twice a net loss, reducing the impact and harmonic interference voltage caused by nonlinear loads, system security, economic operation of great significance.

Abstract: This paper proposed a way of two-level parallel alignment based on sequence parallel vectorization with GPU acceleration on the Fermi architecture, which integrates sequence parallel vectorization, parallel k-means clustering approximate alignment and parallel Smith-Waterman algorithm. The method converts sequence alignment into vector alignment by first. Then it uses k-means alignment to divide sequences into several groups and reduce the size of sequence data. The expected accurate alignment result is achieved using parallel Smith-Waterman algorithm. The high-throughput mouse T-cell receptor (TCR) sequences were used to validate the proposed method. Under the same hardware condition, comparing to serial Smith-Waterman algorithm and CUDASW++2.0 algorithm, our method is the most efficient alignment algorithm with high alignment accuracy.

Abstract: Lead-free thick film resistors (TFRs) were prepared by mixing of ruthenium oxide (RuO₂) and CaO-B₂O₃-SiO₂ based-glass. The resistors were post-fired on alumina and co-fired in LTCC substrates. Different metal oxides were added into the glass phase, such as Nb₂O₅, MnO₂, MoO₃, Fe₂O₃, TiO₂. They were used as temperature coefficient of resistor (TCR) adjustment agents of the resistors. The microstructures variations and interactions at the interface between resistors and substrates were investigated. The additives made glass structure loose and conductivity of resistor decrease, the TCR values of the resistors moved toward negative direction. When 4wt% MnO₂ was added into the glass, the thick-film resistors embedded in LTCC had conductivity of 2.46 (Ω-cm)^-1, the temperature coefficient of resistor decreased to 12 ppm/°C. The conductivities of the resistors films were depended on the volume fractions of conductor-agglomeration (RuO₂), microstructures, and TCR additives of the resistor layers

Abstract: The application of electric power, which acts as a pillar energy and economic artery in modern society, is one of the most important symbols of the level of development and comprehensive national power of a country. Var is a crucial factor for the design and operation of AC power systems, and is closely bound up with the safety, stabilization, and economical operation of power systems. With the development of electrified railway, the importance of the dynamic var compensation for traction power supply systems of electrified railway becomes more and more distinct. Developing the var compensation strategy vigorously has important senses in theory and practice. In this article, synthetically considering technique and economic leval of power systems in our country, parameters modeling and design and verification and specific engineering application of a var compensation method are presented. This method is a preferable one for resolving undesirable effect on power systems from traction power supply systems of electrified railway, especially having dynamic and real time characteristics of var compensation.