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This paper presents a fault location algorithm for single phase to ground faults on three terminal transmission lines. The conventional fault location methods, using one-terminal ac voltage and current are not applicable to the multi-terminal systems. So, the indication of the faulted section and fault distance estimation is performed by using three-phase current and voltage of the terminal at which...
The paper is devoted to the identification of transmission lines from synchronized measurements of current and voltage phasors provided by the phasor measurement units (PMUs). The series and shunt line parameters are recursively estimated using the extended Kalman filter (EKF). Actual line temperature and reference resistance are estimated instead of actual series resistance, which is then computed...
On the roof of an industrial site a 385 kWp PhotoVoltaic installation is operational. When production of this system reaches 60% of the installed power, the circuit breaker trips. At sufficient production, measurements show a high distortion of phase voltage and variable waveform of both phase voltage and current. Analysis of the installation showed that a Yy0 transformer is used introducing a high...
A technique for measuring the current of a stationary spot welding unit using a Hall sensor system is implemented. Hall Effect sensor is used to sense the strength of the magnetic field produced by the current, flowing through the welding electrodes, on the secondary side of welding transformer. In contrast to a current transformer the Hall Effect sensor can read a DC current and can thus be utilized...
In this paper, we introduce an observer-based state of charge (SOC) estimator for batteries. The estimation strategy is based on the battery's state space model. This representation makes stability analysis easier for the proposed estimation technique. Unlike other estimation strategies, only battery terminal voltage and current measurements are required. Simulation results highlight the performance...
In this paper, an algorithm for diagnosis of voltage collapse point is proposed. The algorithm is based on load characteristics, voltage and current measurements. When all loads at a bus are voltage independent type, the voltage collapse point coincides with Maximum Loading Point. In maximum loading point, with voltage and current changes, apparent power delivered to the bus does not increase. In...
This paper presents a new on-line method for motor winding deterioration diagnostic based on the increase in the high frequency leakage current. A differential current sensor is used for the measurement of the leakage current. Traditionally, differential current sensors are used as a protection device, however, in this work their use is extended for health monitoring. In order to validate the proposed...
Spatial variation in process parameters can have a significant impact on parametric yield of integrated circuits. We present a test structure and measurement technique for statistical characterization of process variation with programmable spatial granularity. The proposed structure can measure spatial variation at a desired level of granularity by controlling the leakage and on-current state in different...
This paper presents a new technique for accurate fault location based on voltage measurement from one end of the two-terminal transmission line and Smooth Support Vector Machine (SSVM). Due to common problems of current transformer during fault location and as a result increasing the cost and reduction of the accuracy, proposed technique is independent of current measurement and based on one terminal...
Rogowski coils have been used for decades for non-invasive current measurement when other probe, such as current shunts, current transformers are impracticable. The measurement of diode beam current in pulse power system under vacuum and high voltage are challenging task which requires development of Rogowski coil for specific applications. They operate in large radiation fields, under intense electron...
This paper describes how to measure parameters including temperature, luminous flux, direct current and voltage and alternating current and voltage. It uses embedded system based on Samsung's ARM920T processor S3C2410X and Linux Operating System. The system can measure the parameters of the time, store them in system memory, and send them to clients through network periodically according to internet...
A wide range of current-sensing techniques has been developed to satisfy various electrical and electronics applications requirements. In high-voltage applications, the main issue is the electrical isolation with accurate measurement at low signal levels. Isolated shunt technology is an attractive and versatile solution for current sensing. Electrical isolated products usually need a power supply...
DC motor speed can be indirectly obtained by measuring armature current. As for steady armature current, period estimation method in time domain and spectrogram method in frequency domain have both been adopted to calculate DC motor speed, and experiment results indicate that the spectrogram method has better accuracy. As for starting armature current, the current can be de-noised by the method of...
Distribution System State Estimation (DSSE) stays in focus in all smart grid related topics. In Medium Voltage (MV) networks, in particular, and in distribution networks, in general, DSSE is a prerequisite for smart grid functionality. In this paper a new approach for a three-phase DSSE is presented. It utilizes the most types of analog real time measurements (including current magnitude, active and...
Direct experimental evidence of field emission currents in metallic MEMS devices is presented. For the first time, high resolution I-V curves have been demonstrated for micro-gaps in MEMS-based capacitor/switch-like geometries. The I-V dependence shows a good agreement with the Fowler-Nordheim theory, supporting the hypothesis that field emission plays a significant role in charging phenomena in MEMS...
Possibility of complex resistance parameter measurement within a frequency range by the method of coordinate system displacement on current components is investigated.
For the development of ACFM intelligent and visualization inspection system, based on a large number of finite element simulation results about ACFM crack angle detection, the calculate method of ACFM crack direction by 1-D array probe is present, and the experimental test is designed and conducted with the real crack. Test results show that, when tested by the 1-D probe composed of 4 couples of detecting...
An inverse equivalent current method with full probe correction capabilities and higher-order hierarchical surface current expansion functions is investigated. The approach works with electric and magnetic surface current densities and the triangular surface discretization is fully compatible with the usual models from integral equation solutions by the method of moments. Maximum efficiency and flexibility...
Compared to conventional current sensors, the proposed topology is advantageous because of its high resolution throughout its full measurement range, thus reducing offsets to a minimum. This aim is reached through active offset compensation using an analog/digital chopper/de-chopper. A further advantage is the excellent suppression of 1/f noise and a low noise density (35 nV/√Hz) down to the DC-threshold...
This paper describes power quality audits conducted at hospitals in India. Voltage, current and power measured at various points were used to assess the quality of the power. The main power quality problems found in hospitals were voltage flicker, neutral currents, and harmonic distortion (THD) value. Measurement, analysis and conditioning of power quality has been studied in few different hospitals...
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