• Proceedings of the KIPE Conference
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• 2010.11a
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• pp.36-37
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• 2010

This paper presents a simulation model and results of experiment about analysis of grid-tied wind turbine generator with batteries. The system consists of two inverters and a bidirectional DC/DC converter. These inverters are to capture the maximum active power under varying wind conditions and to keep the DC-link voltage magnitude at a specific level. And the bidirectional DC/DC converter makes battery charging or discharging depend on power gap between wind turbine output and local load.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.177-178
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• 2015

This paper proposes a power smoothing scheme of a doubly-fed induction generator. The proposed scheme aims to mitigate system frequency deviation caused by the variable wind. To achieve this, a dynamic droop loop is used and its gain changes with rate of change of frequency so that it can release a large amount of kinetic energy at the initial stage of a frequency event. The performance of the proposed scheme was investigated in a model system with high wind penetration using EMTP-RV simulator. The test results indicate that the scheme can smooth the output power by absorbing or releasing the output power under a varying wind condition.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.241-245
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• 2005

This study introduces the wind turbine (W/T) noise evaluation procedure required in the international standard (IEC 61400-11) and monitoring system for the evaluation. Noise emission characteristics of a 750kW W/T generator is investigated. Test and evaluation are performed on J48 W/T model which is under operation in Daekwanryung Wind Test Site. With the noise signal, meteorological data and W/T operational data are monitored in real time by the integrated monitoring system using LabVIEW. From the measured noise data, acoustic power level and tonality of the W/T are estimated under the wind speeds required by the international standard.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.51 no.12
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• pp.704-713
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• 2002

This paper describes operational characteristics of wind turbine induction generators interconnected with distribution networks using PSCAD/EMTDC. Due to the simple and durable structure, induction generators are the most common type used in wind Power generation. Generally, induction generators are classified into two groups according to the shape of rotor, one is squirrel-cage type and the other is wound-rotor type. In this study, we simulate the start-up and the output variation of generators interconnected with distribution networks and compare the operational characteristics of squirrel -cage type and wound-rotor type induction generators located in the unfaulted distribution lines about the disturbance occurred on the associated distribution feeders emanated from the substation to which wind turbine generator is connected. In order to obtain the realistic results, we use the radial distribution network of IEEE 13-bus model.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.9
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• pp.5893-5898
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• 2014

This paper proposes a modeling method and operating algorithm of an islanding microgrid that is composed of a Battery Energy Storage System (BESS), wind turbine and diesel generator applied in island areas. Initially, the bilateral AC/DC converter was designed for charge/discharge for frequency and voltage to be maintained within the proper ranges according to the load and weather change, and the operating method was proposed for a diesel generator to operate when power supply from the wind turbine or BESS is insufficient. The proposed modeling and controller design method of BESS was applied to a typical islanded microgrid with a wind turbine and diesel generator. The frequency and voltage was kept within the permissible ranges and the proposed method was proven to be appropriate through simulations.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1172-1173
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• 2008

At the moment, the control ability of wind farms is a prime research concern for the grid integration of large wind farms, due to their required active role in the power system. As more wind turbines are installed, the power from wind energy will start to replace conventional generation units and its influence on power systems cannot be neglected. Besides, because of the intermittent nature of wind the output power of wind turbines fluctuates according to wind speed variation. Especially an isolated power system with small capacity such like Jeju needs more systematic solutions and regulations(grid code). This paper presents the idea of approach for centralized operating wind farm strategy to regulate the wind farm power production to the reference power ordered by the system operator. The doubly fed induction generator(DFIG) can control active and reactive power in feasible range. So wind farm comprised of DFIG has the possibility of a controllable component in the power system. The presented wind farm control has a hierarchical structure with both a wind farm control level and a wind turbine control level.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.14 no.4
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• pp.31-38
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• 2000

Wide operating range and speed control is needed for wind power generating and a Doubly Fed Induction Generator(DFIG) has good adaptivity for that purpose. This paper deals with the speed, power, and power factor control using the Grid connected DFIG in the super-synchronous speed regions, by controlling frequency and voltage fed to the rotor. Power flow of the DFIG and steady-state algebraic equations of the equivalent circuit are analyzed. The wind turbine speed and constant stator power were controlled by the rotor exciting frequency. For a normal operating region, in which the generator ratings were not exceeded, rotor exciting frequency. For a normal operating region, in which the generator ratings were not exceeded, the rotor current was either less than or equal to the rated value. Accordingly, the optimal power factor can be selected relative to the permissible rated current at the rotor coil which controls the magnitude of the injected rotor voltage to the rotor according to a given rotor frequency. Consequently, it is possible to determine the optimal drive of a DFIG for wind power generation application.

• Journal of Electrical Engineering and Technology
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• v.11 no.6
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• pp.1556-1570
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• 2016

In the process of virtual inertia control (VIC), the frequency regulation capability of the directly-driven wind turbine with permanent-magnet synchronous generator (D-PMSG) on wind farm is related to its rotor kinetic energy and capacity margin. This paper proposes the method for assessing the D-PMSG frequency regulation capability and defining its coefficient according to the operating state of wind power generators. In addition, the calculating method of parameters in VIC is also discussed according to the principles of primary frequency regulation and inertia response of synchronous generators. Then, by introducing the capability coefficient into the proportion-differential virtual inertia control (PD-VIC) for power coordination, a coordinated virtual inertia control (C-VIC) strategy is developed, with the consideration of the difference in frequency regulation capability between wind power generators. The proposed control method can not only give full play to the frequency regulation capability of wind power generators, decrease the movements of the pitch angle control system but also bring some self-coordination capability to different wind power generators thus to avoid a secondary drop in system frequency. The simulations and experiments prove the proposed method to be effective and practicable.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.9
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• pp.1491-1499
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• 2008

This paper presents a study on reliability evaluation of a power system considering wind turbine generators (WTG) with multi-state. Renewable energy resources such as wind, wave, solar, micro hydro, tidal and biomass etc. are becoming importance stage by stage because of considering effect of the environment. Wind energy is one of the most successful sources of renewable energy for the production of electrical energy. But, reliability evaluation of generating system with wind energy resources is a complex process. While the wind turbine generators can not modelled as two-state model as like as conventional generators, they should be modelled as multi-state model due to wind speed random variation. The methodology for obtaining reliability evaluation index of wind turbine generators is different from it of the conventional generators. A method for making outage capacity probability table of WTG for reliability is proposed in this paper. The detail process is presented using case study of simple system.

• Proceedings of the KIEE Conference
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• 2003.04a
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• pp.331-334
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• 2003

In this paper, on the subject of a speed control wind turbine, the type of wind speed reference decision between conventional MPPT tracking speed control and MPPT with LPF(Low Pass Filter) speed control algorithm are introduced and its performances are compared using a model based on MATLAB Simulink, and to get more realistic output data, the stored wind data as its wind speed input from 30kW wind power system in Buan, Haechang is used.