• Journal of Electrical Engineering and Technology
• /
• 제9권1호
• /
• pp.60-70
• /
• 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.

• 전력전자학회논문지
• /
• 제19권2호
• /
• pp.149-156
• /
• 2014

This paper proposes the battery charging algorithm for small-scale wind power generator using three phase PWM converter. it is impossible to control output power of the converter in over wind speed region since back EMF of PMSG is higer than battery voltage. Therefore, battery charging algorithm is proposed to expand battery charging over wind speed region. The suggested method is using the q-axis current for battery charging in the rated wind speed region. In the over wind speed region after it lower back EMF of PMSG using d-axis current it can control output power of the converter. The validity of the proposed algorithm are verified by experiments.

• Journal of Power Electronics
• /
• 제9권1호
• /
• pp.85-92
• /
• 2009

This paper studies the method to predict voltage variation that can be presented in the case of operating a small-sized wind turbine in grid connection to the isolated small-sized power system. In order to do this, it makes up the simplified simulation model of the existing power plant connected to the isolated system, load, transformer, and wind turbine on the basis of PSCAD/EMTDC and compares them with the operating characteristics of the actual established wind turbine. In particular, it suggests a simplified model formed with equivalent impedance of the power system network including the load to analytically predict voltage variation at the connected point. It also confirms that the voltage variation amount calculated by the suggested method accords well with both simulation and actually measured data. The results can be utilized as a tool to ensure security and reliability in the stage of system design and preliminary investigation of a small-sized grid connected wind turbine.

• Wind and Structures
• /
• 제30권3호
• /
• pp.261-273
• /
• 2020

This paper deals with the design, wind tunnel testing, and performance analysis of small wind turbines targeting low-power applications. Three different small-size blade designs in terms of size, shape, and twisting angle are considered and tested. We conduct wind tunnel tests while measuring the angular speed of the rotating blades, the generated voltage, and the current under varying resistive loading and air flow conditions. An electromechanical model is also used to predict the measured voltage and power and verify their consistency and repeatability. The measurements are found in qualitative agreement with those reported in previously-published experimental works. We present a novel methodology to estimate the mechanical torque applied to the wind turbine without the deployment of a torque measuring device. This method can be used to determine the power coefficient at a given air speed, which constitutes an important performance indicator of wind turbines. The wind tunnel tests revealed the capability of the developed wind turbines to deliver more than 1225 mW when subject to an air flow with a speed of 7 m/s. The power coefficient is found ranging between 26% and 32%. This demonstrates the aerodynamic capability of the designed blades to extract power from the wind.

• 융합신호처리학회논문지
• /
• 제25권2호
• /
• pp.94-99
• /
• 2024

최근 들어 풍력 발전은 신재생 에너지 중에서 높은 효율을 가진 에너지원으로 주목받고 있으며, 이에 따라 전 세계적으로 다양한 기술 개발이 진행되고 있다. 일반적으로 풍력 발전은 풍력 자원이 풍부한 지역에 많은 풍력터빈을 설치하여 운영하는 대형 풍력 농장(Big Wind Farm) 형태로 운영되고 있으나 개발 도상국이나 전력망에서 고립된 지역에서는 오프-그리드(Off-Grid) 형태의 소형 풍력 발전 시스템이 효율적인 솔루션으로 부상하고 있다. 오프-그리드(Off-Grid) 형태의 소규모 발전 시스템을 효율적으로 운영하고 확산시키기 위해서는 실시간 모니터링 시스템의 개발이 요구된다. 소규모 풍력 발전 시스템 구성을 위해 과다한 풍속으로 인한 손상 방지 체계 및 다양한 환경적 요소에 능동적으로 대처하기 위한 실시간 발전소 운영 모니터링 체계 그리고 생산된 전력을 안정적으로 소규모 지역이나 시설에 공급하기 위한 ESS(Energy Storage System) 시스템에 대해 연구하였다. 구현된 시스템은 터빈의 RPM, 발전량, 브레이크 동작, 발전량 등을 모니터링하여 최적 운영환경이 조성되도록 하였다. 구현된 소형 풍력발전 체계는 격오지 도로 조명, 해양 레저 시설, 모바일 통신 기지국 등에 활용될 수 잇으며 RE100 산업 생태계 발전에 기여할 수 있을 것이다.

• 한국지열·수열에너지학회논문집
• /
• 제12권3호
• /
• pp.9-16
• /
• 2016

This study had the purpose on feasibility judgment through performance forecast of wind power generation system using the cross flow vertical type wind power turbine for the situation of domestic small size wind power technology development. Wind power generation system uses the principle of venturi tube that gathers the wind through the first guide vane, and second guide vein changes the angle of the wind simultaneously by playing the role of venturi tube. After this, wind got out from the second guide vane spins the wind power turbine and has the meaning of judging on the aspect of numerical interpretation the feasibility for the small size wind power generation through wind power generation system that comes out from the back.

• Journal of Electrical Engineering and Technology
• /
• 제13권3호
• /
• pp.1110-1122
• /
• 2018

This paper proposes an alternative method to evaluate the effect of wind power to the power system stability with small disturbance. Alternatively, available techniques for stability analysis of a power system based on deterministic methods are less accurate for high penetration of wind power. Numerical simulations of random behaviors are computationally expensive. A stochastic stability index (SSI) is proposed for the power system stability evaluation based on the theory of stochastic stability and energy function, specifically the stochastic derivative of the relative well-defined energy function and the critical energy. The SSI is implemented on the modified nine-bus system including wind turbines under different conditions. A doubly-fed induction generator (DFIG) wind turbine is characterized and modeled using measured wind data from several sites in Thailand. Each of the obtained wind power data is analyzed. The wind power effect is modeled considering the aggregated effect of wind turbines. With the proposed method, the system behavior is properly predicted and the stability is quantitatively evaluated with less computational effort compared with conventional numerical simulation methods.

• 전기학회논문지
• /
• 제63권4호
• /
• pp.484-489
• /
• 2014

Three phase PWM(Pulse Width Modulation) converter of the small-scale wind power system is able to charge battery under the rated wind speed regions. However, it is impossible to control output power of converter at the over win speed region because back-EMF(Electro Motive Force) of PMSG(Permanent Magnet Synchronous Generator) is higher than the battery terminal voltage of PMSG is reduced. However, the cut-off wind speed exists although battery charging algorithm is implemented by flux weakening control method. Therefore, this paper performs analysis of other factors which affects limitation wind speed. The validity of the analysis are verified through simulation.

• 전기학회논문지
• /
• 제62권12호
• /
• pp.1688-1693
• /
• 2013

A small-scale wind power generation system with a switched-mode rectifier(SMR) is proposed. To simplify the converter circuit of the wind power generation system, the synchronous inductors of the permanent magnet synchronous generator(PMSG) replace the inductor for the boost converter. The sensorless maximum power point tracking(MPPT) control is carried out for the wind power generation system with the SMR. The proposed system is verified through the simulations and the experiments.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
• /
• pp.539-541
• /
• 2009

A severely cold weather condition of King Sejong Station, Antarctica becomes a very severe condition for an installation/operation of wind generation system. When the existing wind generation system works, it may cause a damage and destruction of wind generation system and can bring about big problems in terms of the power quality. Accordingly, it is essential to obtain technologies for the installation and operation of small wind generation system for the polar region's wind generation, and to assess and demonstrate the performance in the severely-cold environment and the polar wind generation system's development, supplementation, alteration. Also, as the available power of King Sejong Station, Antarctica, the diesel generator has been mainly used, and the wind generator has been used in the hybrid form. Wind generation and diesel generation has the different load following control each other. In the wind generation, the generated power very rapidly changes according to the change of the velocity of the wind. On the other hand, the diesel generation shows very gentle change in the velocity of output. Therefore, the study is intended to analyze the 10kw small wind generator-diesel generator's power quality of King Sejong Station, Antarctica, which is the hybrid system installation area.