• Title/Summary/Keyword: adjustable speed drives

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A Method for $\frac{dv}{dt}$ suppression during switching of inverter (인버터 스위칭시 $\frac{dv}{dt}$ 억제 방법)

  • Suh, Duk-Bae;Sul, Seung-Ki
    • Proceedings of the KIEE Conference
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    • 1994.11a
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    • pp.156-158
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    • 1994
  • In recent days, the various adjustable speed drives are widely employed at the industrial applications for the purpose of energy saving and speed control. In particular, for the machine control applications. the switching frequency is required to be increased for better dynamic performance of the drive. Moreover, this also leads to the reduction of the switching loss of the device. For IGBT (Insulated Gate Bipolar Transistor), the most widely used switching device in the inverters below the 100[kW] range, the falling and falling time is of the order about $200{\sim}300[ns]$. Therefore unexpected phenomena occurs such as voltage spikes due to high gradient of current at the switching instant, the weakening of motor insulation due to high gradient of voltage. In this paper, a new voltage gradient suppression technique is presented in both theoretically and experimentally.

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SENSORLESS CONTROL FOR INDUCTION MOTOR USED IN TRACTION APPLICATION (견인용 유도전동기의 센서리스 제어)

  • Ryoo, Hong-Je;Kim, Jong-Soo;Rim, Geun-Hie;Kisck, Dragos Ovidiu;Won, Chung-Yuen
    • Proceedings of the KIEE Conference
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    • 2000.07b
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    • pp.1136-1139
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    • 2000
  • The paper describes a new and rigorous mathematical model for the rotor field oriented system with induction motor which uses the estimated speed and rotor flux based on a Model Reference Adaptive System, as well as the real-time approach. The estimated speed and rotor flux is used for the speed and flux feedback control. The stability and the convergence of the estimator are improved on the basis of hyperstability theory for non-linear systems. The real-time controller and estimator are implemented with a sampling period of $926{\mu}s$ using a dual TMS320C44 floating-point digital signal processor. The validity of the proposed method is verified by simulation, and also, the sensorless control was tested on the propulsion system simulator, used for the development of Korean High-Speed Railway Train (KHSRT) [5].

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Sensorless Control of Rotor Field Oriented Induction Motor for Traction Application (견인 유도전동기의 새로운 센서리스 벡터제어)

  • Ryu, Hong-Je;Kim, Jong-Su;Im, Geun-Hui;Won, Chung-Yeon;Dragos, K
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.49 no.9
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    • pp.626-634
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    • 2000
  • The paper describes a new and rigorous mathematical model using counter-EMF for the rotor field oriented system with induction motor which uses the estimated speed and rotor flux based on a Model Reference Adaptive System as well as the real-time approach. The estimated speed and rotor flux is used for the speed and flux feedback control. The stability and the convergence of the estimator are improved on the basis of hyperstability theory for non-linear systems. The validity of the proposed method is verified by simulation and also the sensorless control was tested on the propulsion system simulator used for the development of Korean High-Speed Railway Train(KHSRT).

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A Sensorless Switched Reluctance Drive System Based on the Improved Simplified Flux Method

  • Li, Zhenguo;Song, Andong;Ahn, Jin-Woo
    • Journal of international Conference on Electrical Machines and Systems
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    • v.1 no.4
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    • pp.477-482
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    • 2012
  • This paper describes a new rotor position sensorless control method for SRM drives based on an improved simplified flux linkage method. In the traditional simplified flux linkage method, every phases take turns conduction and current chopping control method is used. Every phases take turns conduction means turning on the incoming working phase while turning off the working phase. This conduction mode causes coupling between turn-on and turn-off angles, which goes against optimal efficiency or torque ripple minimization with sensorless speed control. In the improved simplified flux linkage method, turn-off angle is calculated by flux loop, the turn-on angle can be given arbitrarily and has no relations with the turn-off angle, and the current chopping control method is used. The speed and rotor position can be estimated then. Finally, a sensorless SRM speed control system and an experiment platform with DSP are built and validity of this method is confirmed.

Modeling of a Switched Reluctance Motor in Sensorless and 'With Sensor' Modes

  • Bhuvaneswari G.;Thakurta Sarit Guha;Rao P. Srinivasa;Murthy S.S.
    • Journal of Power Electronics
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    • v.6 no.4
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    • pp.315-321
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    • 2006
  • Switched Reluctance Motors (SRM) have emerged as viable alternatives to other adjustable speed drives such as vector controlled induction motors (VCIM) and permanent magnet brush-less (PMBL) motors due to their simple construction, ease of control, low inertia and higher operating speeds. However, the indispensability of the rotor position sensor in an SRM for its successful operation increases its cost, apart from causing other problems like decreasing its reliability and inability to operate in adverse environmental conditions. In this paper, a new sensorless control scheme for the SRM is advocated. The required fundamental data is obtained by analyzing the SRM using the Finite Elements (FE) package MAXWELL. The drive is studied in both 'with sensor' and 'sensorless' modes and a comparison of the performances, in both cases, is presented for various operating conditions.

Diagnostic and Active Filtering of Harmonics Generated by Compact Fluorescent Lamps

  • Moulahoum, Samir;Houassine, Hamza;Kabache, Nadir
    • Journal of international Conference on Electrical Machines and Systems
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    • v.3 no.2
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    • pp.162-168
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    • 2014
  • Use of nonlinear loads, such as power converters, fluorescent lamps and adjustable speed motor drives, is expected to grow rapidly. All of these loads inject harmonic currents. This paper presents the active filtering of the harmonic distortion generated by the compact fluorescent lamps (CFL). The Instantaneous active and reactive power theory (the p-q Theory) is used to design the control of parallel active filter. The control scheme has been verified using Matlab/Simulink with SimPower Systems through a set of simulation tests under different load conditions. Also, the tuning of the active power filter is performed to improve the quality of the electrical power supply.

Cost-effective Design of an Inverter Output Reactor in ASD application (전동기 과전압 억제용 OUTPUT REACTOR의 최적 설계)

  • 김한종;이근호;장철호;이제필
    • Proceedings of the KIPE Conference
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    • 1999.07a
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    • pp.65-70
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    • 1999
  • In this paper, the cost-effective design of output reactor which is used to suppress the over-voltage at the motor terminal in the Adjustable Speed Drives(ASD) application is proposed. In the elevator drive system, the power cable length is relatively shorter than other ASD applications and then the over-voltage at the motor terminal depends on the frequency characteristics of the output reactor at the over-voltage operating frequency. The over-voltage suppression mechanism of output reactor in ASD application is analyzed and the dominant parameters of output reactor for the over-voltage suppression are extracted. Using these parameters as the design values and considering the high frequency characteristics of iron core in the reactor, a new cost-effective structure of output reactor is proposed. Experimental results of the conventional reactor and the proposed reactor with a 15kW induction motor are given to verify the proposed scheme.

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Fault Diagnosis of a Electrolytic Capacitor for Inverter DC-Link Voltage Smoothing (인버터 직류링크 전압 평활용 전해 커패시터의 고장 진단)

  • Lee, Kwang-Woon
    • The Transactions of the Korean Institute of Power Electronics
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    • v.12 no.5
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    • pp.372-377
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    • 2007
  • This paper proposes a novel fault diagnosis method of a electrolytic capacitor used for DC-link voltage smoothing in adjustable speed drives. The equivalent series resistance (ESR) of the electrolytic capacitor is directly estimated from DC-link voltage and load currents and the status of the electrolytic capacitor is determined from the estimated ESR. To compensate the variation of the ESR owing to temperature variation, diodes are located on the same PCB near the capacitor and the temperature of the capacitor is sensed indirectly from the voltage drop of diodes. Simulation and experimental studies show the effectiveness of the proposed method.

Design and Analysis of the High Quality Accuracy Voltage sag Compensator (고품질 정밀형 Voltage sag 보상기 설계 및 해석)

  • Oh, Se-Ho;Choi, Hyun-Young;Park, Jung-Gyun;Ryu, Hyoung-Sun;Kim, Yang-Mo
    • Proceedings of the KIEE Conference
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    • 2001.11c
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    • pp.356-358
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    • 2001
  • Voltage sags are known as a serious problem causing mal-operation of equipment, process controllers and adjustable-speed drives. We understand problems of the voltage sag that have a bad effect to the load and then we design for a new model of the compensator. We accomplished system modeling for both sensorless part and sensing part, and compare the merits and demerits of both.

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A Measurement of Switching Surge Voltage Using Inverter devices (인버터의 스위칭 서지전압 측정)

  • Kim, Jong-Gyeum;Jeong, Jong-Ho;Lee, Eun-Woong
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.53 no.1
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    • pp.14-21
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    • 2004
  • Most adjustable-speed drives (ASDs) designed to operate low voltage induction motors incorporate voltage-source inverters (VSIs), which create motor voltages at high switching frequencies. The motor leads used to connect an ASD to a motor can behave like transmission lines for voltage pulses, which can be reflected at the motor terminals. The resulting oscillatory transient, known as the long-lead effect, can stress and consequently degrade the stator insulation system of a motor. This paper describes the results of tests to 1) determine the correlation between peak motor voltage and the length of motor leads and 2) determine the correlation between peak motor voltage and the switching frequency of the ASD Insulation failures like this usually are caused by voltage surges. Voltage surges are often the result of switching power circuits, lightning strikes, capacitor discharges and solid-state power devices.