• Title, Summary, Keyword: Synchronous

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Performance Improvement of Synchronous Generator using Exciter Control with Field Coils Parameter Estimation Technique (계자코일 파라메터추정 기법을 이용한 동기발전기의 성능개선)

  • Kang, Seong-Hyun;Park, Seong-Mi;Lee, Hwa-Chun;Park, Sung-Jun
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.27 no.4
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    • pp.31-40
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    • 2013
  • This paper proposes a performance improvement of synchronous generator using exciter control with field coils parameter estimation technique. In general, the generator excitation system controller uses the PID controller. When the Field winding impedance changed, the PID gains must be changed. General method is difficult to apply varying capacity of the synchronous generator. The proposed control method determine automatically measure the internal impedance of the synchronous generator's exciter and configure the controller. This method can be applied regardless of the generator capacity. So it is possible to apply a variety of synchronous generator systems. The validity of the proposed algorithm is verified by simulations and experiments.

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.

Fault Diagnosis Method of Permanent Magnet Synchronous Motor for Electrical Vehicle

  • Yoo, Jin-Hyung;Jung, Tae-Uk
    • Journal of Magnetics
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    • v.21 no.3
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    • pp.413-420
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    • 2016
  • The permanent magnet synchronous motor has high efficiency driving performance and high power density output characteristics compared with other motors. In addition, it has good regenerative operation characteristics during braking and deceleration driving condition. For this reason, permanent magnet synchronous motor is generally applied as a power train motor for electrical vehicle. In permanent magnet synchronous motor, the most probable causes of fault are demagnetization of rotor's permanent magnet and short of stator winding turn. Therefore, the demagnetization fault of permanent magnet and turn fault of stator winding should be detected quickly to reduce the risk of accident and to prevent the progress of breakdown of power train system. In this paper, the fault diagnosis method using high frequency low voltage injection was suggested to diagnose the demagnetization fault of rotor permanent magnet and the turn fault of stator winding. The proposed fault diagnosis method can be used to check the faults of permanent magnet synchronous motor during system check-up process at vehicle starting and idling stop mode. The feasibility and usefulness of the proposed method were verified by the finite element analysis.

Soft switched Synchronous Boost Converter for Battery Dischargers

  • Dong, Zhiyong;Joung, Gyubum
    • International journal of advanced smart convergence
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    • v.9 no.2
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    • pp.105-113
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    • 2020
  • In this paper, we proposed a soft switched synchronous boost converter, which can perform discharging the battery, is proposed. The proposed converter has low switching loss even at high frequency operation due to its soft switching characteristics. The converter operates in synchronous mode to minimize conduction loss because of changing the rectified diode to MOSFET with a low on resistance. In this reason, the efficiency of the converter can be greatly improved in high frequency. In this paper, the battery discharger with a switching frequency of 100 kHz, has been designed. The designed converter also simulated to prove the converter's characteristics of synchronous operation as well as soft switching operation. The simulation shows that the proposed converter always meets the soft switching conditions of turning on and off switching in the zero voltage and zero current states. Therefore, simulation results have confirmed that the proposed battery discharge had soft switching characteristics. The simulation results have confirmed that the proposed battery discharger had soft switching and synchronous operation characteristics.

A Study on The Synchronous Control of Dual Electric Propulsion System Based on the Coupling Structure (커플링구조에 기초한 전기추진시스템의 동기제어에 관한 연구)

  • Yang, Kyong-Uk;Byun, Jung-Hwan
    • The Journal of the Korea institute of electronic communication sciences
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    • v.13 no.2
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    • pp.349-356
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    • 2018
  • In this study, the synchronous control system is designed to restrain the speed difference generated between two propellers, namely, synchronous error in a dual electric propulsion system of unmanned surface vehicle, fish finder boat, etc. The control system based on coupling structure is composed of pre-filters and speed controllers for each propulsion system and a synchronous controller cross-coupled between two propulsion systems. The pre-filter and speed controller are designed in order that the propulsion system may follow the speed reference without overshoot and input saturation. And the synchronous controller is designed in consideration of damping and quickness of the synchronous controller system after analyzing effect of the skew disturbance and mismatched dynamic characteristics on synchronous error. Finally, the simulation results show that the designed control system is effective for elimination of synchronous error.

The DLB Method for Multimedia Synchronization in the ATM Networks (ATM 망에서 멀티미디어 동기화를 위한 DLB 기법)

  • 구경옥;이병수;조용환
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.22 no.4
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    • pp.842-854
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    • 1997
  • In this paper, the improved Dual Leaky-Bucket(DLB) algorithm is proposed to reduce the synchronous cell loss rate. The conventional DLB algorithm does not support synchronous cells, but the proposed algorithm gives higher priority to synchronous cells. To reduce synchronous cell loss rate, the synchronous cell detector is used in the proposed algorithm. Synchronous cell detector detects synchronous cells, and passes them cells to the 2nd Leaky-Bucket. So it is similar to give higher priority to synchronous cells. In this paper, the proposed algorithm used audio/videl traffic modeled by On/Off and Two-state MMPP, and simulated by SLAM II package. As simulation results, the proposed algorithm gets lower synchronous cell loss rate than the conventional DLB algorithms. The improved DLB algorithm for multimedia synchronization can be extended to any other cells which require higher priority.

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Design of Inter-Regional Instrument Group-B Decoder Based on FPGA for Time Synchronous (시각동기를 위한 FPGA 기반의 Inter-Regional Instrument Group-B 디코더 설계)

  • Kim, Hoon Yong;Yang, Oh
    • Journal of the Semiconductor & Display Technology
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    • v.18 no.1
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    • pp.59-64
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    • 2019
  • Recently, time synchronous has become important for satellite launch control facilities, multiple thermal power plants, and power system facilities. Information from time synchronous at each of these industrial sites requires time synchronization to control or monitor the system with correlation. In this paper, IRIG-B codes, which can be used for time synchronous, are used as specifications in IRIG standard 200-16. Signals from IRIG-B120 (Analog), IRIG-B000 (Digital), and one PPS are output from GPS receiver. Using the signal from IRIG-B120 (Analog), it passes through the signal from the analog amplifier and generates one PPS signal using the field-programmable gate array. The FPGA is used cyclone EPM570T100I5N. According to IEEE regulations, the error of one PPS is specified within 1us, but in this paper, the error is within 100ns. The output of the one PPS signal was then compared and tested against the one PPS signal on the GPS receiver to verify accuracy and reliability. In addition, the proposed time synchronous is simple to construct and structure, easy to implement, and provides high time precision compared to typical time synchronous. The output of the one PPS signals and IRIG-B000 signal will be used in many industry sectors.

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Design and Implementation of Channel Allocation Module of Synchronous Area in MOST Network (MOST 네트워크의 동기영역 채널 할당 모듈 설계 및 구현)

  • Jang, Si-Woong;Kwak, Gil-Bong;Yu, Yoon-Sik
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.14 no.6
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    • pp.1397-1402
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    • 2010
  • While MOST is an in-vehicle network which transfers concurrently synchronous data, asynchronous data and control data, it provides high bandwidth synchronous section which can transfer video and audio without buffering. To transfer real time data using synchronous section, connections between source node and sink node, and channel allocation for connections are required. In this paper, we proposed synchronous data transfer method and channel allocation method by constructing MOST network after designing and implementing channel allocation module for using synchronous data section.

Self-Commissioning for Surface-Mounted Permanent Magnet Synchronous Motors

  • Urasaki, Naomitsu;Senjyu, Tomonobu;Uezato, Katsumi
    • Journal of Power Electronics
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    • v.3 no.1
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    • pp.33-39
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    • 2003
  • This paper presents the self-commissioning for surface-mounted permanent magnet synchronous motor. The proposed strategy executes three tests with a vector controlled inverter drive system. To do this, synchronous d-q axes currents are appropriately controlled for each test. From the three tests, armature resistance, armature inductance, equivalent iron loss resistance, and emf coefficient are identified automatically. The validity of the proposed strategy is confirmed by experimental results.

Simulation of Synchronous Machines Using Object-Oriented Digital Computer Simulator (객체지향기법을 적용한 디지탈 컴퓨터 시뮬레이터를 이용한 동기 발전기 시뮬레이션)

  • Park, Ji-Ho;Baek, Young-Sik
    • Proceedings of the KIEE Conference
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    • pp.102-105
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    • 1995
  • In power system stability analysis, modelling of the synchronous machine is necessary and vary important. In this paper, a synchronous machine is modeled and simulated by using Object-Oriented method. The mathematical equations describing the dynamic behavior of the synchronous machine is represented by block diagram and Objected-Oriented Digital Computer Simulater(ODCS). The developed method is tested for a one-machine-to-infinite-bus system, which is accurate and very useful for a multi-machine system simulation.

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