• Title, Summary, Keyword: Current-voltage

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The New Design of CMOS Voltage-Current Reference Circuit for Stable Voltage-Current Applications (새로운 CMOS 전압-전류 안정화 회로 설계)

  • Kim, Yeong-Min;Hwang, Jong-Sun
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.1239-1243
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    • 2004
  • A novel voltage-current reference circuit for stable voltage-current applications is Proposed. Circuits for a positive and for a negative voltage-current reference are presented and are designed with commercial CMOS technology. The voltage-current reference that is stable over ambient temperature variations is an important component of most data acquisition systems. These results are verified by the HSPICE simulation $0.8{\mu}m$ parameter. As the result, the temperature dependency of output voltage and output current each is $0.57mV/^{\circ}C$, $0.11{\mu}A/^{\circ}C$ and the power dissipation is 1.8 mV on 5V supply voltage.

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Common-Mode Voltage and Current Harmonic Reduction for Five-Phase VSIs with Model Predictive Current Control

  • Vu, Huu-Cong;Lee, Hong-Hee
    • Journal of Power Electronics
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    • v.19 no.6
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    • pp.1477-1485
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    • 2019
  • This paper proposes an effective model predictive current control (MPCC) that involves using 10 virtual voltage vectors to reduce the current harmonics and common-mode voltage (CMV) for a two-level five-phase voltage source inverter (VSI). In the proposed scheme, 10 virtual voltage vectors are included to reduce the CMV and low-order current harmonics. These virtual voltage vectors are employed as the input control set for the MPCC. Among the 10 virtual voltage vectors, two are applied throughout the whole sampling period to reduce current ripples. The two selected virtual voltage vectors are based on location information of the reference voltage vector, and their duration times are calculated using a simple algorithm. This significantly reduces the computational burden. Simulation and experimental results are provided to verify the effectiveness of the proposed scheme.

Current-Voltage-Luminance Characteristics Depending on a Direction of Applied Voltage in Organic Light-Emitting Diodes

  • Kim, Sang-Keol;Hong, Jin-Woong;Kim, Tae-Wan
    • Transactions on Electrical and Electronic Materials
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    • v.3 no.1
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    • pp.38-41
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    • 2002
  • We have investigated current-voltage-luminance characteristics of organic light-emitting diodes based on TPD/Alq$_3$organics depending on the application of forward-backward bias voltage. Luminance-voltage characteristics and luminous efficiency were measured at the same time when the current-voltage characteristics were measured. We have observed that the current-voltage characteristics shows a reversible current maxima at low voltage, which is possibly not related to the emission from Alq$_3$. Current-voltage-luminance characteristics imply that the conduction luminance mechanism at low voltage is different from that of high voltage one.

Variable-magnitude Voltage Signal Injection for Current Reconstruction in an IPMSM Sensorless Drive with a Single Sensor

  • Im, Jun-Hyuk;Kim, Sang-Il;Kim, Rae-Young
    • Journal of Electrical Engineering and Technology
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    • v.13 no.4
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    • pp.1558-1565
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    • 2018
  • Three-phase current is reconstructed from the dc-link current in an AC machine drive with a single current sensor. Switching pattern modification methods, in which the magnitude of the effective voltage vector is secured over its minimum, are investigated to accurately reconstruct the three-phase current. However, the existing methods that modify the switching pattern cause voltage and current distortions that degrade sensorless performance. This paper proposes a variable-magnitude voltage signal injection method based on a high frequency voltage signal injection. The proposed method generates a voltage reference vector that ensures the minimum magnitude of the effective voltage vector by varying the magnitude of the injection signal. This method can realize high quality current reconstruction without switching pattern modification. The proposed method is verified by experiments in a 600W Interior permanent magnet synchronous machine (IPMSM) drive system.

A Fuzzy-PI Control Scheme of the Three-Phase Z-Source PWM Rectifier without AC-Side Voltage and Current Sensors (교류측 전압 및 전류 센서가 없는 3상 Z-소스 PWM 정류기의 퍼지-PI 제어)

  • Han, Keun-Woo;Jung, Young-Gook;Lim, Young-Cheol
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.62 no.6
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    • pp.767-781
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    • 2013
  • In this paper, we proposes the AC input voltage and current sensorless control scheme to control the input power factor and DC output voltage of the three-phase Z-source PWM rectifier. For DC-link voltage control which is sensitive to the system parameters of the PWM rectifier, fuzzy-PI controller is used. Because the AC input voltage and current are estimated using only the DC-link voltage and current, AC input voltage and current sensors are not required. In addition, the unity input power factor and DC output voltage can be controlled. The phase-angle of the detected AC input voltage and estimated voltage, the response characteristics of the DC output voltage according to the DC voltage references, the FFT results of the estimated voltage and current, efficiency, and the response characteristics of the conventional PI controller and fuzzy-PI controller are verified by PSIM simulation.

Current Limit Strategy of Voltage Controller of Delta-Connected H-Bridge STATCOM under Unbalanced Voltage Drop

  • Son, Gum Tae;Park, Jung-Wook
    • Journal of Electrical Engineering and Technology
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    • v.13 no.2
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    • pp.550-558
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    • 2018
  • This paper presents the current limit strategy of voltage controller of delta-connected H-bridge static synchronous compensator (STATCOM) under an unbalanced voltage fault event. When phase to ground fault happens, the feasibility to heighten the magnitude of sagging phase voltage is considered by using symmetric transformation method in delta-structure STATCOM. And the efficiency to cover the maximum physical current limit of switching device is considered by using vector analysis method that calculate the zero sequence current for balancing the cluster energy in delta connected H-bridge STATCOM. The result is simple and obvious. Only positive sequence current has to be used to support the unbalanced voltage sag. Although the relationship between combination of the negative sequence voltage with current and zero sequence current is nonlinear, the more negative sequence current is supplying, the larger zero sequence current is required. From the full-model STATCOM system simulation, zero sequence current demand is identified according to a ratio of positive and negative sequence compensating current. When only positive sequence current support voltage sag, the least zero sequence current is needed.

New Zero-Current-Transition (ZCT) Circuit Cell Without Additional Current Stress

  • Kim Chong-Eun;Choi Eun-Suk;Youn Myung-Joong;Moon Gun-Woo
    • Proceedings of the KIPE Conference
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    • pp.294-298
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    • 2003
  • In this paper, the new zero-current-transition (ZCT) circuit cell is proposed. The main switch is turned-off under the zero current and zero voltage condition, and there is no additional current stress and voltage stress in, the main switch and the main diode. The Auxiliary switch is turned-off under the zero voltage condition, and the main diode is turned-on under the zero voltage condition, The resonant current required to obtain the ZCT is small and regenerated to the input voltage source. The operational principles of the boost converter integrated with the proposed ZCT circuit cell is analyzed theoretically and verified by the simulation and experimental result. Index terms - zero-current-transition (ZCT), zero-current- switching (ZCS), zero-voltage-switching (ZVS)

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A study on single body design of optical current sensor and optical voltage sensor (광전류/광전압 센서의 일체화 설계에 관한 연구)

  • 김영수;김요희
    • 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.

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A study on a modeling method about current-voltage characteristic of HTS tape considering resistance of stabilizer

  • Lee, W.S.;Lee, J.;Nam, S.;Ko, T.K.
    • Progress in Superconductivity and Cryogenics
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    • v.15 no.3
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    • pp.9-12
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    • 2013
  • Current-voltage characteristic models of superconducting material are suggested by many researchers. These current-voltage characteristic models are important because they can be used for design or simulation of superconductor devices. But widely used current-voltage models of superconductor wire still have some limitations. For example, a standard E-J power model has no parameters related with stabilizer's resistance in superconductor wire. In this paper, a current-voltage characteristic modeling method for high temperature superconductor (HTS) tape with considering the effect of stabilizer is introduced. And a current-voltage characteristic of a HTS tape is measured under different stabilizer conditions. Those measured current-voltage characteristics of the HTS tape modeled with proposed modeling method and the modeling results are compared.

High-linearity voltage-controlled current source circuits with wide range current output (넓은 범위의 전류 출력을 갖는 고선형 전압-제어 전류원 회로)

  • 차형우
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.41 no.7
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    • pp.89-96
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    • 2004
  • High-linearity voltage-controlled current sources (VCCSs) circuits for wide voltage-controlled oscillator and automatic gain control are proposed. The VCCS consists of emitter follower for voltage input, two common-base amplifier which their emitter connected for current output, and current mirror which connected the two amplifier for large output current. The VCCS used only five transistors and a resistor without an extra bias circuit. Simulation results show that the VCCS has current output range from 0㎃ to 300㎃ over the control voltage range from 1V to 4.8V at supply voltage 5V. The linearity error of output current has less than 1.4% over the current range from 0A to 300㎃.