• Journal of Power Electronics
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• v.10 no.6
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• pp.733-738
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• 2010

This paper deals with a ride-through technique for permanent-magnet synchronous generator (PMSG) wind turbine systems using energy storage systems (ESS). A control strategy which consists of current and power control loops for the energy storage systems is proposed. By increasing the generator speed, some portion of the turbine power can be stored in the system inertia. Therefore, the required energy capacity of the ESS can be decreased, which results in a low-cost system. In addition, the power fluctuations due to wind speed variations can be smoothened by controlling the ESS appropriately. The effectiveness of the proposed method is verified not only by the simulation results for a 2[MW] PMSG wind turbine system, but also by the experiment results for a reduced-scale turbine simulator.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.59-63
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• 2005

The 800-kW PM (permanent magnet) synchronous generator is developed as a wind power generator. The matching converter is designed to control the torque and power depending on the wind speed regime. The generator starts to generate the power at the speed of 9 rpm and the rated output is generated at the speed of 25 rpm. The rated output power of an inverter is 750 kW when the PM synchronous generator is delivering 800 kW to the inverter. The inverter is specially designed to perform the maximum power point tracking (MPPT) at the low wind speed regime that is typical wind environment in Korea. The inverter test was done with a 2 MW M-G system at KERI (Korea Electric Research Institute). The M-G set has a 2 MW motor driver and a 38:1 gear to match the speed between the motor and the PM generator. The torque simulating the wind is applied to the PM generator by a DC motor. The test results show the inverter efficiency of $94.3\%$ at the rated power generating condition. The measured values show that the MPPT algorithm is working well. Overall reliability will be verified through the long-term site test.

• Journal of the Korean Solar Energy Society
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• v.34 no.2
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• pp.8-15
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• 2014

The objective of this paper is to suggest a design topology of permanent magnet synchronous generator with 2,000kW capacities for wind turbine. The suggested topology is to provide 3 split magnet PMSG instead of single magnet, and performed an analysis of eddy current loss and iron loss for suggested type using ansoft maxwell commercial program. The simulation results of suggested magnet type show there duction of eddy current loss as 13.87kW with loadless conditions and23.48kW with rated conditions, but iron loss for rotor yoke show the in creasing trend as2.2kW with loadless conditions and 0.2kW with rated conditions. The suggested 3 split maget type is to identified as more useful for 2,000kW PMSG.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.11a
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• pp.95-99
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• 2005

This paper presents a general proposal to design and calculate the performance of a tubular permanent magnet linear generator treated here on the basis of the Finite Element Method. Optimizing the linear generator dimensions reduces the cogging force, which occurs due to the interaction between stator teeth and the permanent magnets. The generated AC voltage is analyzed and evaluated for both no load and load cases to take the armature reaction effects on the air gap flux density. A repetitive routine is followed to calculate the output AC voltage from the change of flux and the speed of the single-phase linear generator. The AC output voltage is calculated for different resistive loads, and hence, the linear generator load characteristic is obtained. The designed linear generator is capable to generate an output power of 5.3kW with AC output voltage of 222V with an efficiency of 96.8% at full load of 23.8A. The full load current is chosen based on the thermal properties of the coil wire insulations.

• Journal of Electrical Engineering and Technology
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• v.9 no.1
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• pp.60-70
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• 2014

This paper discusses the impacts of large scale grid-connected wind farm equipped with permanent magnet synchronous generator (PMSG) on power system small signal stability (SSS) incorporating wind generation uncertainty and volatility. Firstly, a practical simplified PMSG model with rotor-flux-oriented control strategy applied is derived. In modeling PMSG generator side converter, the generator-voltage-oriented control strategy is utilized to implement the decoupled control of active and reactive power output. In modeling PMSG grid side converter, the grid-voltage-oriented control strategy is applied to realize the control of DC link voltage and the reactive power regulation. Based on the Weibull distribution of wind speed, the Monte Carlo simulation technique based is carried out on the IEEE 16-generator-68-bus test system as benchmark to study the impacts of wind generation uncertainty and volatility on small signal stability. Finally, some preliminary conclusions and comments are given.

• Journal of IKEEE
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• v.28 no.3
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• pp.382-389
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• 2024

In this paper, a design of dynamic braking resistor for stationary mode of azimuth driving equipment (ADE) for multi-function radar (MFR) is presented. The ADE carries out missions which is the rotation mode for all directions and the stationary mode for tracing a subject with standstill. The ADE has to transfer the operation mode in demand time from rotation mode to stationary mode for precise target tracing. During the transition with deceleration, it may cause the fault of input power device due to back-electromotive force (back-EMF) of PMSM with generator mode. To protect the power device, a design of dynamic braking resistor is essential for consuming back-EMF. This paper presents the development of dynamic braking resistor for consuming back-EMF of ADE with deceleration mode. The validity and effect of the design is verified using simulation results.

• Journal of the Korean Solar Energy Society
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• v.34 no.2
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• pp.16-23
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• 2014

This paper presents a renewable energy configuration plan of Micro grid in Gapa Island. To analyze the characteristics of Micro grid, BESS (Battery Energy Storage System), PMSG (Permanent Magnet Synchronous Generator) and SCIG (Squirrel Cage Induction Generator) are first modelled. The PMSG and SCIG will operate with basis on the real power curve. when the total power demand is larger than the total power generation, the BESS will be operated and the SOC (State Of Charge) is reduced. If the value of SOC could drop down to limited value, the system may be broken because of the voltage drop of BESS. To solve this problem, a DG (Diesel Generator) is used to charge the BESS and keep the voltage value of BESS with in a allowance limit. This paper represents simulation result when PMSG, SCIG connected to the Micro grid installed in Gapa Island. The simulation is carry out by using PSCAD/EMTDC program with actual line constant and transformer parameter in Gapa Island.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.7
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• pp.57-66
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• 2009

Microturbines system (MTS) are currently being deployed as small scale on-site distributed generators for microgrids and smart grids. In order to fully exploit DG potentialities, advanced integrated controls that include power electronics facilities, communication technologies and advanced modeling are required. Significant expectations are posed on gas microturbines that can be easily installed in large commercial and public buildings. Modeling, control, simulation of microturbine generator based distributed generation system in smart grid application of buildings for both grid-connected and islanding conditions are presented. It also incorporates modeling and simulation of MT with a speed control system of the MT-permanent magnet synchronous generator to keep the speed constant with load variation. Model and simulations are performed using MATLAB, Simulink and SimPowerSystem software package. The model is built from the dynamics of each part with their interconnections. This simplified model is a useful tool for studying the various operational aspects of MT and is also applicable with building cooling, heating and power (BCHP) systems

• Journal of IKEEE
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• v.21 no.1
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• pp.81-84
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• 2017

As the demands for offshore wind power generation systems on a large scale have grown dramatically, and extensive developments in PMSG (Permanent Magnet Synchronous Generator) and DFIG (Doubly-fed Induction Generator) wind turbine system have been going on. However, the wind power systems have been more sophisticated, and their reliability becomes critical issues. Averagely, wind turbines have shut down for about a week per year for repairs and maintenance. Especially the high speed gearbox of DFIG is inevitable components for high power generation, but becomes one of the critical failures. In this paper, a new reliable gearless wind turbine structure is proposed. The gearless wind turbine can operate on a maximum power points by controlling the speed of a rotational stator. The proposed approach is verified by PSIM simulations, resulting in increased energy reliability.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.10
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• pp.1481-1486
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• 2013

The small wind generator with existing mechanical control system has a frequent failure and malfunction, and its maintenance is difficult. In this paper, an electric control method using a boost converter for small wind generator was suggested. The suggested 2-level boost converter control device was manufactured and its experimental operation were conducted on a wind generator with 200 [W] capacity. As a result of experimental device, the control by a boost converter was executed at the point that the output voltage of a wind generator became 36 [V] so it could be identified that the output voltage of a wind generator diminished and then it became 0 [V] after 5 [sec]. Besides, in case of applying the method suggested in this paper to a small wind power generation facility for street lights, it is expected to reduce its maintenance by preventing a frequent failure of a generator and to improve its utilization rate.