• Title, Summary, Keyword: synchronous generator

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Analysis and Compensation of Current Measurement Errors in a Doubly Fed Induction Generator

  • Son, Yung-Deug;Im, Won-Sang;Park, Han-Seok;Kim, Jang-Mok
    • Journal of Electrical Engineering and Technology
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    • v.9 no.2
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    • pp.532-540
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    • 2014
  • It is necessary to measure the current of rotor for controlling the active and reactive power generated by the stator side of the doubly fed induction generator (DFIG) system. There are offset and scaling errors in the current measurement. The offset and scaling errors cause one and two times current ripples of slip frequency in the synchronous reference frame of vector control, respectively. This paper proposes a compensation method to reduce their ripples. The stator current is variable according to the wind force but the rotor current is almost constant. Therefore input of the rotor current is more useful for a compensation method. The proposed method adopts the synchronous d-axis current of the rotor as the input signal for compensation. The ripples of the measurement errors can be calculated by integrating the synchronous d-axis stator current. The calculated errors are added to the reference current of rotor as input of the current regulator, then the ripples are reduced. Experimental results show the effectiveness of the proposed method.

Voltage Controller Design of Synchronous Generator by Pole Assignment (극배치에 의한 동기발전기의 전압제어기 설계)

  • Yim, Han-Suck
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.34 no.12
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    • pp.472-484
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    • 1985
  • A design of robust voltage controller for high speed excitation of synchronous machine was carried out by pole assignment techniques. An affine map from characteristic polynomial coefficients to feedback parameters is formulated in order to place the system eigen values in the desired region. The feedback parameters determined from linearized model are tested on nonlinear model subjecting it to small disturbances and system faults to show the effectiveness of the controller designed by the proposed technique. The results obtained indicate that the controller presented improves the dynamic stability and system performances of conventionally controlled synchronous machine significantly.

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Transient Analysis of Synchronous Machine (동기 발전기의 과도 해석)

  • Park, Chul-Won;Park, Chang-Soo;Shin, Kwang-Chul
    • Proceedings of the KIEE Conference
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    • pp.120-125
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    • 2006
  • In this paper, the voltage equation of a synchronous machine is established using the two-axis theory. And we were simulated model of the synchronous generator for power system fault analysis. It can be used to analyze important features of faults and to develope enhanced protection methods.

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Starter/Alternator Systems for HEV and Their Control: A Review

  • Boldea, Ion.
    • KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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    • v.4B no.4
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    • pp.157-169
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    • 2004
  • Motor & generator operation at widely variable speeds is needed in various applications but hybrid and electric vehicle (HEV) stand out today, as quite a few companies are launching this year their mass production of HEVs. The quest for better starter-generators is far from ended, though. The present review paper unfolds a comparative critical evaluation of various starter-generators and their control for HEV. Induction, interior PM synchronous, transverse-flux PM synchronous, switched reluctance, together with claw-pole and biaxial excitation PM synchronous (BEGA) configurations with their control are all considered in system evaluations.

Development of Generator Excitation System with Main/Standby Controller in In-chun Thermal power plant #4 (인천화력 4호기 발전기용 주/부 제어기를 갖는 정지형 여자시스템 개발)

  • 류호선;임익헌
    • Proceedings of the KIPE Conference
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    • pp.407-410
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    • 1999
  • Potential-source controlled excitation system had been developed for synchronous generator in In-Chun thermal power plant #4 by KEPRI. This paper describes the characteristics of Main/Standby control system employed analog, digital circuit devices (hybrid type) and 3 PCRs(Phase Controlled Rectifier)

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Design of synchronous VHDL Code Generator from Synchronous SpecCharts (Synchronous SpecCharts로부터 Synchronous VHDL 코드 생성기 설계)

  • 윤성조;안성용;이정아
    • Proceedings of the Korean Information Science Society Conference
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    • pp.54-56
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    • 1999
  • 현재 많은 내장형 시스템을 구현하기 위한 방법론으로 가상 프로토타입(VP)을 이용하고 있다. 본 논문에서는 가상 프로토타입을 이용하여 내장형 시스템의 설계 및 구현을 위해 사용되는 시스템 명세 언어인 SpecCharts로 명세된 시스템을 동기적 의미론에 만족하는 SpecCharts의 Subset을 규명하여 동기화 형태로 해당명세를 변환시키고 이로부터 synchronous VHDL 코드로 생성할 수 있는 방법을 설계하였다. 동기적 의미론을 만족시키기 위하여 비결정적인 추상적인 모델(NDAM)을 이용하여 SpecCharts로부터 VHDL ?로 변환하는 방법을 제시하고, 변환된 VHDL 코드를 동기적 VHDL 코드로 변환하기 위하여 W. Baker에 의해 규명된 동기적 VHDL subset 적용하여 synchronous VHDL 코드를 생성하는 방법을 제안한다.

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Analysis of Impact on Voltage Stability by Starting Synchronous Condenser in Jeju AC Network (제주계통에서 동기조상기 기동에 따른 전압안정도 영향 검토)

  • Choi, Soon-Ho;Lee, Seong-Doo;Kim, Chan-Ki
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.64 no.1
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    • pp.23-28
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    • 2015
  • Two old synchronous condensers in Jeju are being replaced by new machines to operate Jeju AC network with Haenam-Jeju HVDC system stably. Before new synchronous condensers operate on site, voltage stability analysis is conducted to verify stable operation of jeju AC network. Through impedance analysis of the synchronous machine, transformer and ac network, the equivalent circuit is constructed and the voltage drop during start-up is calculated. Then, PSS/E fault analysis is performed to acquire short-circuit capacity according to the generator operation scenarios. Voltage variation when starting synchronous condenser is simulated in PSCAD/EMTDC and satisfies the operating condition of jeju AC network and HVDC #1 system.

Model Predictive Power Control of a PWM Rectifier for Electromagnetic Transmitters

  • Zhang, Jialin;Zhang, Yiming;Guo, Bing;Gao, Junxia
    • Journal of Power Electronics
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    • v.18 no.3
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    • pp.789-801
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    • 2018
  • Model predictive direct power control (MPDPC) is a widely recognized high-performance control strategy for a three-phase grid-connected pulse width modulation (PWM) rectifier. Unlike those of conventional grid-connected PWM rectifiers, the active and reactive powers of permanent magnet synchronous generator (PMSG)-connected PWM rectifiers, which are used in electromagnetic transmitters, cannot be calculated as the product of voltage and current because the back electromotive force (EMF) of the generator cannot be measured directly. In this study, the predictive power model of the rectifier is obtained by analyzing the relationship among flux, back EMF, active/reactive power, converter voltage, and stator current of the generator. The concept of duty cycle control in the proposed MPDPC is introduced by allocating a fraction of the control period for a nonzero vector and rest time for a zero vector. When nonzero vectors and their duration in the predefined cost function are simultaneously evaluated, the global power ripple minimization is obtained. Simulation and experimental results prove that the proposed MPDPC strategy with duty cycle control for the PMSG-connected PWM rectifier can achieve better control performance than the conventional MPDPC-SVM with grid-connected PWM rectifier.

Real-Time Hardware Simulator for Grid-Tied PMSG Wind Power System

  • Choy, Young-Do;Han, Byung-Moon;Lee, Jun-Young;Jang, Gil-Soo
    • Journal of Electrical Engineering and Technology
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    • v.6 no.3
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    • pp.375-383
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    • 2011
  • This paper describes a real-time hardware simulator for a grid-tied Permanent Magnet Synchronous Generator (PMSG) wind power system, which consists of an anemometer, a data logger, a motor-generator set with vector drive, and a back-to-back power converter with a digital signal processor (DSP) controller. The anemometer measures real wind speed, and the data is sent to the data logger to calculate the turbine torque. The calculated torque is sent to the vector drive for the induction motor after it is scaled down to the rated simulator power. The motor generates the mechanical power for the PMSG, and the generated electrical power is connected to the grid through a back-to-back converter. The generator-side converter in a back-to-back converter operates in current control mode to track the maximum power point at the given wind speed. The grid-side converter operates to control the direct current link voltage and to correct the power factor. The developed simulator can be used to analyze various mechanical and electrical characteristics of a grid-tied PMSG wind power system. It can also be utilized to educate students or engineers on the operation of grid-tied PMSG wind power system.

The Comparison Analysis between Psim Simulation and Motor-Generator (MG) Set Output Characteristics (Psim시뮬레이션과 전동기-발전기(MG) 세트의 출력특성분석)

  • Lim, Hyung-Tack;Jo, Da-Som;Son, Hyo-Soo;Moon, Sang-Soo;Lee, Seok-Hyun;Kim, Kun-Su;Jo, Chul-Hee
    • New & Renewable Energy
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    • v.10 no.3
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    • pp.31-38
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    • 2014
  • The importance of energy is growing according to the energy shortage and environmental concerns. Accordingly, in order to solve the problems about the use of fossil fuel, a renewable energy sources are needed. Global renewable energy power industry's position in the renewable energy market becomes important and new technology development is also essential. MG set composed by the induction motor and permanent magnet synchronous generator for simulating a renewable energy source is based on a suitable experiment equipment. The torque generated by applying a voltage to the induction motor in MG set is used as an input of the permanent magnet synchronous generator. In Psim simulation, the characteristics of the induction motor model was formulated and the output torque characteristics of the motor was controlled using the induction motor side inverter, In this paper, the comparison analysis between Psim simulation and the output characteristics of the MG set is performed in order to identify a renewable energy power system more accurately.