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Normally, fault resistances come out with errors in the fault calculation algorithm on conventional Mho distance protection scheme which might force the relay to under-reach/over-reach based on the network conditions. With a constrained shape, Mho Directional distance elements can provide more resistive coverage while discriminating between forward and reverse faults. In this work, the recurring effect...
In this work, a fundamental new approach for humidity detection was proposed. By coupling triboelectric nanogenerator (TENG) with resistive humidity sensor, the degree of ambient moisture can be actively detected at room temperature, where the voltage drop across the interdigital electrodes (IDEs) has a reversely proportional relationship with relative humidity. The prepared self-powered triboelectric...
This paper proposes methods for improvement electrical grounding systems performance. There is a intense need for efficient electrical protection systems, to protect people and property against electric currents discharges, thus adding improvements to electrical grounding systems already in use. Based on this principle, this work is divided in: i) soil resistance values variation, due to different...
Recently graphene got a lot of attention for its potential use in microwave applications owing to its tunability properties. Graphene changes its resistance values from very high values to very low values upon the application of a voltage bias. This is particularly interesting in the design of microwave and millimeter wave components and structures. The use of few-layer graphene (FLG) is particularly...
Hydro-generators with skewed armature slots have damper interbar currents that flow transversely between the damper bars through the core. The interbar currents may involve harmonic and local overheating issues. The interbar resistance is a vital factor that affects the distributions of interbar currents and damper bar currents. A multislice finite-element model with integrated interbar circuit is...
Dealing with high testing costs remains an important problem in Software Engineering. Test suite parallelization is an important approach to address this problem. This paper reports our findings on the usage and impact of test suite parallelization in open-source projects. It provides recommendations to practitioners and tool developers to speed up test execution. Considering a set of 468 popular...
Stator inter-turn faults are among the most important electric motor failures as they progress fast and lead to catastrophic motor breakdowns. Inter-turn faults are caused due to the windings' insulation degradation. The main stress which deteriorates the insulation is the thermal one. Proper understanding of how this stress influences the electrical properties of insulation over time may lead to...
In stable electrical networks, such as the German one, the service of uninterruptible power supply (UPS) systems is only rarely called. Consequently the battery lifetime in this application is mostly restricted by calendar aging. The concept of multi-use describes here the delivery of additional services with a UPS during stable grid operation. The overall goal is to allocate the battery capacity...
Inductive loosely coupled wireless power transmission (WPT) system is characterized by heterogeneous magnetic field of the transmitter. The voltage at receiver's output varies with position of the receiver, with design of the receiver's LC tank circuit, and with the load resistance. This paper measures the impact of these three parameters on receiver's output voltage and output power. Paper also evaluates...
Many schools are incorporating project-based interdisciplinary exercises into their engineering curriculum in order to develop the qualitative and quantitative skills simultaneously. It has been shown that introducing design in a freshman engineering course has a positive impact on retention, stimulates interest in engineering and enhances communication, teaming and time management skills. But can...
Skin resistance is one of the important indexes in psychological affective researches, and it can reflect the change of emotion by recording its changes. Generally, the skin resistance measurement method is connecting the electrode sensor to the two adjacent fingers of the object to record the resistance signal, and then amplifying, collecting and recording the signal by amplification circuit. However,...
Grounding fault and injecting AC into DC control system in substation may lead to many protector problems, such as maloperation and miss trip, Based on the traditional unbalanced bridge and blocking condenser principle, the IUB(Improved Unbalanced Bridge) is put forward to detect ground resistance and alternating voltage occurred in substation DC system. The circuit of IUB models in MATLAB/Simulink...
High voltage pulse trimming is the most suitable resistance adjustment method for contemporary thick-film applications that impose stricter requirements on thick-film resistors. In this paper the influence of trimming by energy of high voltage pulses on two thick-film resistor quality indicators that are based on noise index measurements is being examined. Since standard characterization of trimmed...
The current zero period of vacuum arc determines the breaking performance of vacuum circuit breakers, and post-arc current is one of main parameters of current zero period. DC vacuum circuit breaker is one practical solution to solve the bottleneck of DC transmission circuit breaker. It is difficult to measure the post-arc current, when artificial current zero method is used to break the DC short...
High voltage circuit breakers are most important protective device in power system. Dynamic contact resistance measurement (DRM) is considered to be an effective assessment technique for contact ablation which has been widely used for many years. However, the contact resistance curves will be influenced by many factors, such as injected current and velocity. In power systems, circuit breakers often...
This paper presents a study about the impulse impedance of grounding grids based on experimental measurements performed within a testing field developed for this purpose. It considers an extensive number of measurement sets performed in grounding grids with different dimensions and topologies. The main goal is to evaluate an appropriate procedure to be employed during field measurements, as well as...
This paper presents a procedure to acquire precise measurement data of the output characteristics with a custom-made setup. In comparison to datasheets and common curve tracer measurements, the measurement range is extended and the accuracy improved. After deriving the theoretical minimal switching energy for semiconductor switches in a half-bridge configuration, possible operating points of the latest...
This paper presents the study, design and simulation of a laboratory module related to filters. With this laboratory platform it was accomplish a comparative study between current feedback (CFA) and voltage feedback (VFA). Because the laboratory platform has an educational role, it was presented some practical aspects of active filters measurement and also the differences between the measured values...
The paper defines the main causes of impermissible dynamic loads in the shaft assemblies of a horizontal plate mill stand. It substantiates the development and commercialization of a stationary telemetry system for continuous control of the torque of the shaft assemblies at the 5,000 mm mill stand at Magnitogorsk Iron and Steel Works, OJSC. The authors determine the main system functions and list...
The sensing potential of a nanocrystalline graphite (NCG) film deposited using plasma enhanced chemical vapour deposition (PECVD) for detecting concentration changes of ammonium nitrate and ammonium sulphate in aqueous solutions was demonstrated using a two-terminal resistive sensing setup. The sensor shows high linearity in the reduction of resistance with increasing salt concentrations when tested...
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