• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.6
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• pp.1596-1603
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• 1996

A single body type of fiber-optic current and voltae sensor using a rare earth doped YIG and a bismuth silicon oxide single crystsl is proposed, which is used for simultaneous measurement of the AC electric current and AC electric voltage over the trasmission lines. Experimental results showed that the fiber-optic current sensor has the maximum 7.5% error within the current range of 0A to 400A, and the fiber-optic voltage sensor has the maximum 0.87% error within the current range of 0V to 400V. The output waveforms of proposed fiber-optic sensor system has a good agreement with output waveforms of conductor current and voltage. Experimental results proved that the output of fiber-optic current sensor is not affected by the electric voltage applied to the fiber-optic voltage sensor, and also, that the output of fiber-optic voltage sensor is not affected by the electric current applied to the fiber-optic current sensor.

• JSTS:Journal of Semiconductor Technology and Science
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• v.14 no.6
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• pp.810-817
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• 2014

An on-chip current sensor with fast response time for the peak-current-mode buck regulator is proposed. The initial operating points of the peak current sensor are determined in advance by the valley current level, which is sensed by a valley current sensor. As a result, the proposed current sensor achieves a fast response time of less than 20 ns, and a sensing accuracy of over 90%. Applying the proposed current sensor, the peak-current-mode buck regulator for the mobile application is realized with an operating frequency of 2 MHz, an output voltage of 0.8 V, a maximum load current of 500 mA, and a peak efficiency of over 83%.

• Journal of Sensor Science and Technology
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• v.14 no.2
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• pp.91-95
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• 2005

A fiber Fabry-Perot interferometric sensor for the measurement of current flowing into a small fuse have been studied. The proposed current sensor was fabricated with a fiber Fabry-Perot interferometer attached close to a fuse line inside a small fuse. The fiber Fabry-Perot interferometer used in the experiment had the 10 mm cavity length and the 3.5 % reflectance mirrors. The phase shift of the output signal of the current sensor was proportional to the square of current applied to the fuse and the sensitivity of the current sensor was 0.87 degree/$mA^{2}$. The experiment results show that this sensor can be used for measuring current flowing into the fuse.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.12
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• pp.1045-1053
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• 2002

This paper describes characteristics of the developed current sensor by means of two identically wound magnetic cores forming a clamp like for measurement of a low DC, or AC current. This sensor consists of peak value detectors, a sensor of an electrically compensated current transformer type, a reference alternating voltage, Precision measuring circuits to measure the output signals of sensor with harmonics, and can be measured up to 2 A at DC, or AC current. The current sensor shows a measurement accuracy of less than 0.3% in the frequency range 40 Hz - 10 HBz. The resolution and sensitivity of the sensor were evaluated 0.1 mA and 10 mV/mA, respectively.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.8
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• pp.688-693
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• 2000

In this paper an optical voltage sensor and an optical current sensor which can be used for the measurement of impulse voltage and current are implemented. BSO single crystal is utilized as a voltage sensor(Pockels effect cell). An rare earth doped YIG is used as a current sensor(Faraday effect cell). A new signal processing technique is adopted not only to avoid the influences o external optical fiber pertubations of transmitting optical fiber but also to improves the frequency response characteristics of the fiber-optic voltage and current sensors. Experimental results show that optical voltage sensor has maximum 2.5% error within the voltage range from 0V to 500V. and optical current sensor has maximum 2.5% error within the current range and that of optical current sensor is about 1.5% within temperature range from -2$0^{\circ}C$ to 6$0^{\circ}C$. The proposed optical sensors have good frequency response characteristics within the frequency range from DC to 10MHz.

• Interaction and multiscale mechanics
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• v.3 no.3
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• pp.257-266
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• 2010

A novel resonance based proximity DC current sensor is proposed. The sensor consists of a piezo sensed and actuated cantilever beam with a permanent magnet mounted at its free end. When the sensor is placed in proximity to a wire carrying DC current, resonant frequency of the beam changes with change in current. This change in resonant frequency is used to determine the current through the wire. The structure is simulated in micro and meso scale using COMSOL Multi physics software and the sensor is found to be linear with good sensitivity.

• Journal of Sensor Science and Technology
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• v.29 no.5
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• pp.283-292
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• 2020

Current sensors that use a Hall element and Hall IC to measure the magnetic fields generated in steel silicon core gaps do not distinguish between direct and alternating currents. Thus, they are primarily used to measure direct current (DC) in industrial equipment. Although such sensors can measure the DC when installed in expensive equipment, ascertaining problems becomes difficult if the equipment is set up in an unexposed space. The control box is only opened during scheduled maintenance or when anomalies occur. Therefore, in this paper, a method is proposed for facilitating the safety management and maintenance of equipment when necessary, instead of waiting for anomalies or scheduled maintenance. A Bluetooth 4.0 low-energy current-sensor system based on near-field communication is used, which compensates for the nonlinearity of the current-sensor output signal using a piecewise linear model. The sensor is controlled using its generic attribute profile. Sensor nodes and cell phones used to check the signals obtained from the sensor at 50-A input currents showed an accuracy of ±1%, exhibiting linearity in all communications within the range of 0 to 50 A, with a stable output voltage for each communication segment.

• Journal of Power Electronics
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• v.9 no.1
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• pp.68-73
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• 2009

Automotive inverters may require current sensors for motor torque control, especially, in applications of hybrid electric vehicles or fuel cell vehicles. In this paper, to achieve a compact, integrated and low cost current sensor, a hall current sensor without magnetic core is introduced for integrating an automotive inverter. The compactness of the current sensor is possible by using integrated magnetic concentrators based on the Hall effect. Magnetic fields caused by three-phase currents are analyzed and a magnetic shield design is proposed for decoupling the cross-coupled field. It offers galvanic isolation, wide bandwidth (>100kHz), and accuracy(< 1%). Using 2D FEM analysis, its performance is demonstrated with design parameters at a U-shaped magnetic shield. The proposed coreless current sensor is tested with rated current to validate the linearity and accuracy.

• Journal of Power Electronics
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• v.11 no.6
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• pp.837-845
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• 2011

This paper proposes phase current reconstruction techniques for two-phase two-leg and two-phase four-leg inverters using a single current sensor. In the proposed methods, one phase current is sampled simultaneously with a particular branch current by using only one current sensor, and then current reconstruction algorithms are applied to extract the information on two phase currents from the sensor output. The sampled current information is periodically updated at the peak and the valley of the triangular carrier waveform in each switching cycle of pulse-width modulation (PWM). The voltage vector spaces where the phase currents can be reconstructed are evaluated. Compared to the existing method using two individual current sensors in two phases, the proposed schemes can save implementation cost since it is possible to remove one current sensor. In addition, the proposed methods are free from gain discrepancy issues between two current sensors. Simulations and experiments show excellent current reconstruction performance of the proposed methods.

• Journal of Electrical Engineering and Technology
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• v.11 no.4
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• pp.905-914
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• 2016

This paper proposes a new phase current reconstruction technique for interleaved three-phase bidirectional dc-dc converters using a single current sensor. In the proposed current reconstruction algorithm, a single current sensor is employed at the dc-link, and the dc-link current information is sampled at either the peak or valley point of the pulse-width modulation (PWM) carriers regularly. From the obtained current information, all phase currents are reconstructed in a single PWM cycle. After that, the digital current controller is applied to achieve current balancing in each phase. Compare to the previous multiple current sensor method, the proposed strategy reduces the number of the current sensors in the interleaved three-phase bidirectional converter as well as reducing potential current sensing error caused by non-ideal characteristics of the multiple current sensors. The effectiveness of the proposed method is verified from the experiments based on a 3kW three-phase bidirectional converter prototype for the automotive battery charging application.