• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.981-982
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• 2011

This paper discusses design aspects of slotless permanent magnet generator for high performance and low speed applications. The airgap flux density in was obtained from finite element analysis and the design of a PM generator. The relatively large diameter stator laminations of such machines tend, therefore, to have a very thin back of core and narrow teeth, which make them expensive and difficult to manufacture. this thesis proposes an alternative PM generator topology featuring a slotless stator whose laminations are manufactured from a split core. The test results with a resistive load confirm the satisfactory operation of generator.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.1
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• pp.117-124
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• 2012

In this paper, an analysis of the joint that transmits power from the blades to the generator is performed using the FEM (finite element method). The mode shapes and natural frequencies were extracted using experimental modal analysis in order to establish the FEM model. Then, the model was verified by comparing the mode shapes and natural frequencies to those obtained from the ANSYS modal analysis. Dynamic stress analysis was performed at the rated and limited wind speeds considering the wind load and gravity.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.6
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• pp.675-680
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• 2012

Wind energy is currently the fastest growing source of renewable energy used for electrical generation around the world. Wind farms are adding a significant amount of electrical generation capacity. The increase in the number of wind farms has led to the need for more effective operation and maintenance. CMS(Condition Monitoring System) can be used to aid plant operator in achieving these goals. Its aim is to provide operators with information regarding th e health of their machine, which in turn, can help them improve operation efficiency. In this work, wind turbine fault diagnostic algorithm which can diagnose the mass unbalance and aerodynamic asymmetry of the blades is proposed. Proposed diagnostic algorithm utilizes both FFT(Fast Feurier Transform) of the signal from accelerometers installed inside of nacelle and simple diagnostic logic. Furthermore, to verify the applicability of the proposed system, 3W small sized wind turbine system is tested and physical experiments are carried out.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.10
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• pp.1402-1411
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• 2014

In this paper, the Maximum Power Point Tracking(MPPT) control of the small scale wind power generation system with a three-phase diode rectifier and the grid-connected inverter is studied. Without the need for the converter circuits to control speed of the generator, it is economical and the structure is simple. Compared with existing systems, it can be to reduce the power semiconductor switches and passive elements, and to implement the MPPT control with only DC-Link voltage control of the grid-connected inverter. In order to allow MPPT control without the characteristic information of the wind turbine, the P&O algorithm is applied, and these are verified by the simulation and experiment.

• 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.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.9
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• pp.1560-1565
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• 2010

The renewable resource are getting more attentions with increased concerns on the depletion of fossil fuels and several environmental issues like emission problem. Wind power is a representative option among several renewable sources and the generation capacity using wind power is being increased. However, the wind generation is so volatile on its output characteristic, so it is required to assess the grid impact of wind power generation by measuring the fluctuation effect more precisely. This paper proposes the method for measuring the generation output according to IEC 61400-21(Measurement and assessment of power quality characteristics of grid connected wind turbines) to assess the power quality of wind turbine generation. In addition, it shows an application case to a small-scale wind power generator. In the case study, it suggests a structure design of the proposed measurement instrument both on hardware and software aspects, which is composed of a remote monitoring & data analysis program and an FPGA based real-time signal processing device.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.3B no.1
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• pp.10-15
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• 2003

This paper presents the digital computer performance evaluations of the three-phase self-excited induction generator (SEIG) driven by the variable speed prime mover such as the wind turbine using the nodal admittance approach steady-state frequency domain analysis with the experimental results. The three-phase SEIG setup is implemented for small-scale rural renewable energy utilizations. The experimental performance results give a good agreement with those ones obtained from the digital computer simulation. Furthermore, a feedback closed-loop voltage regulation of the three-phase SEIG as a power conditioner which is driven by a variable speed prime mover employing the static VAR compensator (SVC) circuit composed of the thyristor phase controlled reactor (TCR) and the thyristor switched capacitor(TSC) is designed and considered herein for the wind-turbine driven the power conditioner. To validate the effectiveness of the SVC-based voltage regulator of the terminal voltage of the three-phase SEIG, an inductive load parameter disturbances in stand-alone are applied and characterized in this paper. In the stand-alone power utilization system, the terminal voltage response and thyristor triggering angle response of the TCR are plotted graphically. The simulation and the experimental results prove the effectiveness and validity of the proposed SVC which is controlled by the Pl controller in terms of fast response and high performances of the three-phase SEIG driven directly by the rural renewable energy utilization like a variable-speed prime mover.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.4
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• pp.605-612
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• 2017

One of the biggest environmental issues that our world has been facing is climate change. In order to cope with such environmental issues, the world is putting a great deal of effort into energy conservation. The building sector, in particular, consumes 36% of the energy consumed worldwide and emits considerable amount of greenhouse gases. Therefore, introduction of renewable energies in the building sector is highly recommended. Renewable energy sources that can be utilized in the building sector include sunlight, solar heat, geothermal heat, fuel cells and wind power. The wind power generation system which converts wind energy into electrical energy has advantages in that wind is an unlimited and pollution-free resource. It is suitable to be connected to existing buildings because many years of operational experience and the enhanced stability of the system have made it possible to downsize the electrical generator. In case of existing buildings, it is necessary to consider the live loads of the buildings to connect the wind power generation system. This paper, through the connection of the wind power generation with existing buildings, promotes reduction of greenhouse gas emissions and energy independence by reducing energy consumption in the building sector. In order to connect the wind power generation system with an exciting building, the live load of the building and the area of the rooftop should be considered. The installable model is selected by comparing the live load of the building and the load of the wind power generation system. The maximum number of the wind turbines that can be installed is obtained by considering the separation distance between the wind turbines within the area of the rooftop. Installations are divided into single installations and multiple installations of two different types of wind turbines. After determining the maximum installable number, the optimal model that can achieve the maximum annual power generation will be selected by comparing the respective total annual amount of the power generation of different models.

• Proceedings of the KIEE Conference
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• 2001.10a
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• pp.301-304
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• 2001

Wind power generation system is one of the most useful energy resource using natural environment. One of the biggest problem we encountered is toot the wind speed is fluctuating sharply according to the weather conditions rather than it is stable. In this paper we do the equivalent modeling the mechanical energy of wind power turbine according to wind speed into the synchronous generator. We analyse the equivalent modeling output part of rectifier into DC/DC converter input part theoretically. We analyse a battery charging characteristics for power storage enabling the supply of stable power to the load. We design a system and do the modeling of it analytically so that it supplies a stable power to the load by constructing a DC-AC inverter point. Also we make a small size model usable in actual wind power generation system of 30kw and make an experiment and confirm its validity.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.3
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• pp.16-23
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• 2012

This paper relates to a study on the economic of electrical storage device for supplying power in sunless days, in the stand alone PV/Wind hybrid system, which it is applied to separate houses. In a photovoltaic/wind hybrid power system used in a separate house, when only the battery is used in sunless days, the capacity of the battery is become larger. For example, as in recent days, if cloudy days are frequent due to anomaly climate, it is difficult to supply power stably by only the battery based upon pre-estimated sunless days. Accordingly, in order to supply stably power of new renewable energy such as solar to any separate houses, it is preferable to reduce the capacity of battery by decreasing the number of sunless days when estimating the capacity of battery and to drive the small generator for compensation of the power shortage.