• Title/Summary/Keyword: current source inverter

Search Result 557, Processing Time 0.025 seconds

A Robust Current Control Technique with a Simple Time Delayed Estimator for a Permanent Magnet Synchronous Motor Drive (간단한 시간 지연 관측기를 이용한 영구자석 동기전동기 구동 강인 전류제어 기법)

  • 김경화;윤명중
    • The Transactions of the Korean Institute of Power Electronics
    • /
    • v.5 no.2
    • /
    • pp.140-148
    • /
    • 2000
  • A robust current control technique with a simple time delayed estimator for a permanent magnet synchronous m motor (PMSM) drive is presented. Among the various CWTent control schemes for a voltage source inverter-fed P PMSM drive, the predictive control is known to give a superior performance. This control technique, however, r requires the full knowledge of machine parameters and operating conditions, and gives an unsatisfactory r response under the parameter mismatch between the motor and controller. To overcome such a limitation, the d disturbances caused by the parameter valiations will be estimated by using a" time delay contTol approach and u used for the computation of the reference voltages by a simple feedforwal"d control. The proposed control $ scheme is implemented on a PMSM using the software of DSP TlVIS:32OC:30 and the effectiveness is verified d through the comparative simulations and experiments.periments.

  • PDF

DC-Link Voltage Ripple Analysis of Minimum Loss Discontinuous PWM Strategy in Two-Level Three-Phase Voltage Source Inverters (최소 손실 불연속 변조 기법에 따른 2레벨 3상 전압원 인버터의 직류단 전압 맥동 분석)

  • Lee, Junhyuk;Park, Jung-Wook
    • The Transactions of the Korean Institute of Power Electronics
    • /
    • v.26 no.2
    • /
    • pp.120-126
    • /
    • 2021
  • DC-link capacitors are one of the main components in two-level three-phase voltage source inverters (VSIs); they provide the pulsating input current and stabilize the vacillating DC-link voltage. Ideally, the larger the capacitance of DC-link capacitors, the better the DC-link voltage stabilizes. However, high capacitance increases the cost and decreases the power density of VSI systems. Therefore, the capacitance should be chosen carefully on the basis of the DC-link voltage ripple requirement. However, the DC-link voltage ripple is dependent on the pulse-width modulation (PWM) strategy. This study especially presents a DC-link voltage ripple analysis when the minimum loss discontinuous PWM strategy is applied. Furthermore, an equation for the selection of the minimum capacitance of DC-link capacitors is proposed. Experimental results with R-L loads are also provided to verify the effectiveness of the presented analysis.

Harmonic Mitigation and Power Factor Improvement using Fuzzy Logic and Neural Network Controlled Active Power Filter

  • Kumar, V.Suresh;Kavitha, D.;Kalaiselvi, K.;Kannan, P. S.
    • Journal of Electrical Engineering and Technology
    • /
    • v.3 no.4
    • /
    • pp.520-527
    • /
    • 2008
  • This work focuses on the evaluation of active power filter which is controlled by fuzzy logic and neural network based controller for harmonic mitigation and power factor enhancement. The APF consists of a variable DC voltage source and a DC/AC inverter. The task of an APF is to make the line current waveform as close as possible to a sinusoid in phase with the line voltage by injecting the compensation current. The compensation current is estimated using adaptive neural network. Using the estimated current, the proposed APF is controlled using neural network and fuzzy logic. Computer simulations of the proposed APF are performed using MATLAB. The results show that the proposed techniques for the evaluation of APF can reduce the total harmonic distortion less than 3% and improve the power factor of the system to almost unity.

A Bidirectional Single-Stage DC/AC Converter for Grid Connected Energy Storage Systems

  • Chen, Jianliang;Liao, Xiaozhong;Sha, Deshang
    • Journal of Power Electronics
    • /
    • v.15 no.4
    • /
    • pp.1026-1034
    • /
    • 2015
  • In this paper, a unified control strategy using the current space vector modulation (CSVM) technique is proposed and applied to a bidirectional three-phase DC/AC converter. The operation of the converter changes with the direction of the power flow. In the charging mode, it works as a buck type rectifier; and during the discharging mode, it operates as a boost type inverter, which makes it suitable as an interface between high voltage AC grids and low voltage energy storage devices. This topology has the following advantages: high conversion efficiency, high power factor at the grid side, tight control of the charging current and fast transition between the charging and discharging modes. The operating principle of the mode analysis, the gate signal generation, the general control strategy and the transition from a constant current (CC) to a constant voltage (CV) in the charging mode are discussed. The proposed control strategy has been validated by simulations and experimental results obtained with a 1kW laboratory prototype using supercapacitors as an energy storage device.

A Study on the Smoke Removal Characteristics of the ESP Adopting Resonant dc-dc Converter

  • Kim, Su-Weon;Park, Jong-Woong;Joung, Jong-Han;Chung, Hyun-Ju;Choi, Jin-Young;Kim, Hee-Je
    • KIEE International Transactions on Electrophysics and Applications
    • /
    • v.4C no.5
    • /
    • pp.193-200
    • /
    • 2004
  • In this study, we propose a small high voltage power supply, which uses a half-bridge ZCS resonant and Cockroft-Walton circuit as its ESP (Electrostatic Precipitator). This power supply transfers energy from the ZCS resonant inverter to the step-up transformer. The transformer secondary is then applied to the Cockroft-Walton circuit for generating high voltage as a discharging source of electrodes. It is highly efficient because its amount of switching losses are reduced by virtue of the current resonant half-bridge inverter, and also due to the small size, low parasitic capacitance in the transformer stage owing to the low number of winding turns of the step up transformer secondary combined with the Cockroft-Walton circuit. Using this power supply, experiments have been carried out as a function of the switching frequency and duty ratio in order to investigate the smoke removal characteristics. From these results, the best operational condition is obtained at the switching frequency of 9 kHz and the duty ratio of 50% in this ESP.

New Approach for Transient Radiation SPICE Model of CMOS Circuit

  • Jeong, Sang-Hun;Lee, Nam-Ho;Lee, Jong-Yeol;Cho, Seong-Ik
    • Journal of Electrical Engineering and Technology
    • /
    • v.8 no.5
    • /
    • pp.1182-1187
    • /
    • 2013
  • Transient radiation is emitted during a nuclear explosion and causes fatal errors as upset and latch-up in CMOS circuits. This paper proposes the transient radiation SPICE models of NMOS, PMOS, and INVERTER based on the transient radiation analysis using TCAD (Technology Computer Aided Design). To make the SPICE model of a CMOS circuit, the photocurrent in the PN junction of NMOS and PMOS was replaced as current source, and a latch-up phenomenon in the inverter was applied using a parasitic thyristor. As an example, the proposed transient radiation SPICE model was applied to a CMOS NAND circuit. The CMOS NAND circuit was simulated by SPICE and TCAD using the 0.18um CMOS process model parameter. The simulated results show that the SPICE results were similar to the TCAD simulation and the test results of commercial CMOS NAND IC. The simulation time was reduced by 120 times compared to the TCAD simulation.

High-Frequency Flyback Transformer Linked PWM Power Conditioner with An Active Switched Capacitor Snubber

  • Mun, Sang-Pil;Kim, Soo-Wook;Joo, Seok-Min;Park, Young-Jun
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.22 no.7
    • /
    • pp.7-15
    • /
    • 2008
  • A single active capacitor snubber-assisted soft-switching sinewave pulse modulation utility-interactive power conditioner with a three-winding flyback high frequency transformer link and a bidirectional active power switch in its secondary side has been proposed. With the aid of the switched-capacitor quasi-resonant snubber cell, the high frequency switching devices in the primary side of the proposed DC-to-AC sinewave power inverter can be turned-off with ZVS commutation. In addition to this, the proposed power conditioner in the DCM can effectively take the advantages of ZCS turn-on commutation. Its output port is connected directly to the utility AC power source grid. At the end, the prototype of the proposed HF-UPC is built and tested in experiment. Its power conversion conditioning and processing circuit with a high frequency flyback transformer link is verified and the output sinewave current is qualified in accordance with the power quality guidelines of the utility AC interactive power systems.

Fabrication, Mesurement and Evaluation of Silicon-Gate n-well CMOS Devices (실리콘 게이트 n-well CMOS 소자의 제작, 측정 및 평가)

  • Ryu, Jong-Seon;Kim, Gwang-Su;Kim, Bo-U
    • Journal of the Korean Institute of Telematics and Electronics
    • /
    • v.21 no.5
    • /
    • pp.46-54
    • /
    • 1984
  • A silicon-gate n-well CMOS process with 3 $\mu$m gate length was developed and its possibility for the applications was discussed,. Threshold voltage was easily controlled by ion implantation and 3-$\mu$m gate length with 650 $\AA$ oxide shows ignorable short channel effect. Large value of Al-n+ contact resistance is one of the problems in fabrications of VLSI circuits. Transfer characteristics of CMOS inverter is fairly good and the propagation delay time per stage in ring oscillator with layout of (W/L) PMOS /(W/L) NMOS =(10/5)/(5/5) is about 3.4 nsec. catch-up occurs on substrate current of 3-5 mA in this process and critically dependent on the well doping density and nt-source to n-well space. Therefore, research, more on latch-up characteristics as a function of n-well profile and design rule, especially n+-source to n-well space, is required.

  • PDF

A Novel Prototype of Duty Cycle Controlled Soft-Switching Half-Bridge DC-DC Converter with Input DC Rail Active Quasi Resonant Snubbers Assisted by High Frequency Planar Transformer

  • Fathy, Khairy;Morimoto, Keiki;Suh, Ki-Young;Kwon, Soon-Kurl;Nakaoka, Mutsuo
    • Journal of Electrical Engineering and Technology
    • /
    • v.2 no.1
    • /
    • pp.89-97
    • /
    • 2007
  • This paper presents a new circuit topology of active edge resonant snubbers assisted half-bridge soft switching PWM inverter type DC-DC high power converter for DC bus feeding power plants. The proposed DC-DC power converter is composed of a typical voltage source-fed half-bridge high frequency PWM inverter with a high frequency planar transformer link in addition to input DC busline side power semiconductor switching devices for PWM control scheme and parallel capacitive lossless snubbers. The operating principle of the new DC-DC converter treated here is described by using switching mode equivalent circuits, together with its unique features. All the active power switches in the half-bridge arms and input DC buslines can achieve ZCS turn-on and ZVS turn-off commutation transitions. The total turn-off switching losses of the power switches can be significantly reduced. As a result, a high switching frequency IGBTs can be actually selected in the frequency range of 60 kHz under the principle of soft switching. The performance evaluations of the experimental setup are illustrated practically. The effectiveness of this new converter topology is proved for such low voltage and large current DC-DC power supplies as DC bus feeding from a practical point of view.

A High-Performance Sensorless Control System of Reluctance Synchronous Motor with Direct Torque Control

  • Kim Min-Huei;Kim Nam-Hun;Choi Kyeong-Ho;Kim Dong-Hee;Hwang Dong-Ha
    • Proceedings of the KIPE Conference
    • /
    • 2001.10a
    • /
    • pp.355-359
    • /
    • 2001
  • This paper presents an implementation of digital control system of speed sensorless for Reluctance Synchronous Motor (RSM) drives with DTC. The control system consists of stator flux observer, rotor position/speed/torque estimator, two hysteresis band controllers, an optimal switching look-up table, IGBT voltage source inverter, and TMS320C31 DSP controller by using fully integrated control software. The stator flux observer is based on the combined voltage and current model with stator flux feedback adaptive control that inputs are current and voltage sensing of motor terminal with estimated rotor angle for wide speed range. The rotor position is estimated by observed stator flux-linkage space vector. The estimated rotor speed is determined by differentiation of the rotor position used only in the current model part of the flux observer for a low speed operating area. It does not require the knowledge of any motor parameters, nor particular care for motor starting, In order to prove the suggested control algorithm, we have a simulation and testing at actual experimental system. The developed sensorless control system is shown a good speed control response characteristic results and high performance features in 50/1000 rpm with 1.0Kw RSM having 2.57 ratio of d/q reluctance.

  • PDF