Atsushi Sakahara - Profile on Academia.edu (original) (raw)

Papers by Atsushi Sakahara

A Novel Idea Generation Method, “SA method”

Affective and Pleasurable Design

“A technique for producing ideas” (James Webb Young,1940) has been a bible for advertising people... more “A technique for producing ideas” (James Webb Young,1940) has been a bible for advertising people since its publication. It says, “An idea is nothing more nor less than a new combination of old elements.''(P.15) It also says, “ An idea is a new combinations”.(P.20). But it never mentions how you can combine ideas with an excuse: “This part of the process is harder to describe in concrete terms because it goes on entirely inside your head.”(P.20) Another well known technique for idea producing is the “KJ method”(Jiro Kawakita,"Abduction”1967). It is an approach to find ideas by organizing ideas and it doesn't explain how you can produce ideas by combining elements.Now we are in an era where creation is the important drive force of economic activities in our society and creation is producing ideas. But still the process of producing ideas is in the veil. I am a film director, educator, as well as management consultant. Many of my students and clients need to find an idea with an objective such as career goal, new business idea, project idea. When I help them, I often deploy techniques I use for developing movie projects. I realized I always go through the same path with them. So I developed the “SA method” based on the path I always go through with my students or clients. I am now developing a software application based on the method.Combining two ideas is not so difficult but combining three ideas is extremely difficult. “SA method” helps people to produce ideas by combining three elements. “SA method” assumes an idea with three elements must be a “synthesis” produced by an aufheben in dialectic development with two elements. And each of three elements must be a synthesis produced in dialectic development with the rest respectively. When an idea is produced with three elements, the dialectic is revolved with the same three elements so that the idea is kneaded. “SA method” also has a process of quantifying it and describing it, which not only helps to ferment ideas in mind but also helps to select ideas at each proper timing. This selection also helps to separate the idea generation stage and the idea selection stage. According to my observation, people, who are not good at producing ideas, don’t know the importance of the separation. The SA method is a unique combination of practical and original use of dialectic development and Analytical Hierarchy processing.I conducted pilot tests with 35 undergraduate students at Utsunomiya University and 6 undergraduate students at Chuo University in November of 2021 to find their career goal using the SA method. During the trial, some people had difficulties producing 25 ideas. There may be some reasons such as not being accustomed to generating ideas and “SA method”, and 25 was an unnecessarily large number. Also they didn’t have enough time to search for information about their career development.We are now considering how to refine the methodology. Also, we have started to develop a Web based tool or PC application to work with the “SA method” visually. I would like to conduct further research projects such as comparing “SA method” with “KJ method” while refining the method.

Monsters Are Attacking Tokyo: The Incredible World of Japanese Fantasy Films

Stabilization of Power System by Virtual Inertia Control of Adjustable Speed Synchronous Condenser

In recent years, renewable energy has attracted attention as a measure against global environment... more In recent years, renewable energy has attracted attention as a measure against global environmental problems, and along with that, the penetration of inverter based power sources has been increasing. However, since there is no inertial force in the inverter based power supply, if the penetration is expanded, the inertial force of the entire power system will decrease and thus the stability may decrease. Therefore, a new virtual inertia control method using an adjustable speed synchronous condenser (ASSC) is proposed in this paper. The proposed virtual inertia control method, which is designed based on the Fuzzy Logic theory can contribute to prevent the decrease of the inertial force of the power system. It can improve the stability of the power system when the Squirrel Cage Induction Generator (SCIG) based Wind Farm (WF) trips. Performance of the proposed system is evaluated by using a model system consisting of conventional Synchronous Generators (SGs), ASSC and WF. From the analysis results, it can be confirmed that the proposed method improves the stability of the system.

Voltage control and virtual synchronous generator control of HVDC interconnection line for improving stability of power system including large‐scale wind farm

Iet Generation Transmission & Distribution, Jul 4, 2021

Large-scale integration of renewable energy sources (RESs) such as wind power can impact on the e... more Large-scale integration of renewable energy sources (RESs) such as wind power can impact on the existing power system's stability. For example, there is a possibility that the wind farm (WF) cannot be maintained stable and then it is disconnected from the grid when the instantaneous voltage sag caused by a grid disturbance occurs. Moreover, the increasing integration of RESs in the power system can reduce the number of conventional synchronous generators (SGs) connected to the grid, and lead to a reduction of system inertia in the grid. The system inertia reduction can cause larger and faster frequency fluctuations during the transient period. Hence, this paper proposes a new control strategy composed of the voltage control for suppressing the voltage sag and the virtual synchronous generator (VSG) control based on the proportional-integral-differential (PID) fuzzy logic control (FLC) for maintaining the frequency stability which is performed by high voltage direct current (HVDC) interconnection line. The aim of the new control strategy is to improve the stability of the entire power system with large-scale integration of RESs. The effectiveness of the proposed strategy is confirmed through the simulation analyses by PSCAD/EMTDC.

Ieej Transactions on Power and Energy, 2005

Recently, wind power generation is increasing in the world. In the wind power stations, induction... more Recently, wind power generation is increasing in the world. In the wind power stations, induction machines are mostly used as generators. Since induction generators have a stability problem similar to the transient stability of synchronous machines, it is important to analyze the transient stability of power systems including wind generators. Although there have been some reports analyzing the transient stability problem, wind turbine and wind generator are, in most cases, modeled as one mass shaft system having total inertia constant. This paper presents simulation analyses of transient stability of power system including induction generator which is expressed by a two-mass shaft model and analyzes an effect of shaft system modeling on the transient stability characteristics. Simulations are performed by PSCAD/EMTDC in this study.

Stability Improvement of Power System with a Wind Farm by the Virtual Synchronous Generator Control of Battery

IEEJ Transactions on Power and Energy

Stability Enhancement of Power System by Cooperative Virtual Synchronous Generator Control between ASSC and LFC Hydro Power Plant

IEEJ Transactions on Power and Energy

Stability Enhancement of Power System including Wind Farm by Voltage Control and Virtual Synchronous Generator Control

2021 2nd International Conference on Robotics, Electrical and Signal Processing Techniques (ICREST), 2021

A huge number of renewable energy sources (RESs) has been connected to the existing power system,... more A huge number of renewable energy sources (RESs) has been connected to the existing power system, which has impact on the power system stability. Especially, the power system with large-scale wind farm (WF) may not be maintained stable during transient period due to the voltage dip caused by a network fault. To solve the power system stability issue, a new cooperative control method composed of the voltage control and the PID Fuzzy Logic Control (FLC) based Virtual Synchronous Generator (VSG) control by High Voltage Direct Current (HVDC) transmission line, a battery, and the LFC hydro power plant is proposed. To confirm the effectiveness of this proposed strategy, power system stability analyses are implemented on PSCAD/EMTDC.

Stabilization of Power System by Virtual Inertia Control of Adjustable Speed Synchronous Condenser

2021 2nd International Conference on Robotics, Electrical and Signal Processing Techniques (ICREST), 2021

In recent years, renewable energy has attracted attention as a measure against global environment... more In recent years, renewable energy has attracted attention as a measure against global environmental problems, and along with that, the penetration of inverter based power sources has been increasing. However, since there is no inertial force in the inverter based power supply, if the penetration is expanded, the inertial force of the entire power system will decrease and thus the stability may decrease. Therefore, a new virtual inertia control method using an adjustable speed synchronous condenser (ASSC) is proposed in this paper. The proposed virtual inertia control method, which is designed based on the Fuzzy Logic theory can contribute to prevent the decrease of the inertial force of the power system. It can improve the stability of the power system when the Squirrel Cage Induction Generator (SCIG) based Wind Farm (WF) trips. Performance of the proposed system is evaluated by using a model system consisting of conventional Synchronous Generators (SGs), ASSC and WF. From the analysis results, it can be confirmed that the proposed method improves the stability of the system.

A Consideration on the Stabilization of Wind Generator by Pitch Control System

A new concept of welfare psychology

International Journal of Psychology, 2016

Voltage control and virtual synchronous generator control of HVDC interconnection line for improving stability of power system including large‐scale wind farm

IET Generation, Transmission & Distribution, 2021

Large-scale integration of renewable energy sources (RESs) such as wind power can impact on the e... more Large-scale integration of renewable energy sources (RESs) such as wind power can impact on the existing power system's stability. For example, there is a possibility that the wind farm (WF) cannot be maintained stable and then it is disconnected from the grid when the instantaneous voltage sag caused by a grid disturbance occurs. Moreover, the increasing integration of RESs in the power system can reduce the number of conventional synchronous generators (SGs) connected to the grid, and lead to a reduction of system inertia in the grid. The system inertia reduction can cause larger and faster frequency fluctuations during the transient period. Hence, this paper proposes a new control strategy composed of the voltage control for suppressing the voltage sag and the virtual synchronous generator (VSG) control based on the proportional-integral-differential (PID) fuzzy logic control (FLC) for maintaining the frequency stability which is performed by high voltage direct current (HVDC) interconnection line. The aim of the new control strategy is to improve the stability of the entire power system with large-scale integration of RESs. The effectiveness of the proposed strategy is confirmed through the simulation analyses by PSCAD/EMTDC.

Proceedings for Annual Meeting of The Japanese Pharmacological Society, 2021

Although monoamine-based pharmacological drugs revolutionized the treatment of major depressive d... more Although monoamine-based pharmacological drugs revolutionized the treatment of major depressive disorder, about one third of patients experience treatment-resistant depression. Thus, development of antidepressant with novel mechanism is required. In this study, we investigated the involvement of microsomal prostaglandin E synthase-1 (mPGES-1), a terminal inducible enzyme for PGE 2 synthesis, in acute restraint stress (RS: 6 hr) and social defeat stress (SDS: 1 day). mPGES-1 mRNA was significantly increased after RS. Induction of mPGES-1 protein was observed in neurons in the frontal cortex (FC). PGE 2 in FC was also significantly upregulated in wild-type (WT) mice, but not in mPGES-1 knockout (ES1KO) mice. The inflammatory responses, such as increases in GFAP and TNF-α, observed after RS in ES1KO were significantly less than those in WT. After RS, there were no significant differences between WT and ES1KO in open field test (OFT), forced swimming test, elevated plus maze test (EPM) and marble burying test. On the other hand, in sucrose preference test, the ratio of sucrose intake after RS in WT was significantly less than that in ES1KO. In acute SDS model, social avoidance behavior was significantly observed after SDS. At the same time, upregulation of mPGES-1 was also observed in FC, amygdala and ventral tegmental area. Taken together, these results suggest that mPGES-1 is induced by acute stress in FC, and then contributes to brain inflammation and anhedonia through PGE 2 production. Thus, mPGSE-1 may be a promising novel therapeutic target for depression.

Virtual Synchronous Generator Control of Power System including Large-scale Wind Farm by Cooperative Operation between Battery and LFC Hydro Power Plant

IEEJ Transactions on Power and Energy, 2020

Journal of Power and Energy Engineering, 2020

Recently, introduction of renewable energy sources like wind power generation and photovoltaic po... more Recently, introduction of renewable energy sources like wind power generation and photovoltaic power generation has been increasing from the viewpoint of environmental problems. However, renewable energy power supplies have unstable output due to the influence of weather conditions such as wind speed variations, which may cause fluctuations of voltage and frequency in the power system. This paper proposes fuzzy PD based virtual inertia control system to decrease frequency fluctuations in power system caused by fluctuating output of renewable energy sources. The proposed new method is based on the coordinated control of HVDC interconnection line and battery, and energy balancing control is also incorporated in it. Finally, it is concluded that the proposed system is very effective for suppressing the frequency fluctuations of the power system due to the large-scale wind power generation and solar power generation and also for keeping the energy balancing in the HVDC transmission line.

Journal of international Conference on Electrical Machines and Systems, 2013

In this paper an application of centralized pitch angle controller for fixed speed wind turbines ... more In this paper an application of centralized pitch angle controller for fixed speed wind turbines based wind farm to mitigate load frequency fluctuation is presented. Reference signal for the pitch angle of each wind turbine is calculated by using proposed centralized control system based on wind speed information. The wind farm in the model system is connected to a multi machine power system which is composed of 4 synchronous generators and a load. Simulation analyses have been carried out to investigate the performance of the controller using real wind speed data. It is concluded that the load frequency of the system can be controlled smoothly.

単地点での日射量時系列に基づく10km四方内の空間平均日射量時系列の生成および変動幅出現頻度による評価

IEEJ Transactions on Power and Energy, 2014

風力発電機出力平滑化用エネルギー貯蔵装置の定格決定に関する検討

IEEJ Transactions on Power and Energy, 2012

ABSTRACT This paper proposes an evaluation method for determining the power rating of Energy Stor... more ABSTRACT This paper proposes an evaluation method for determining the power rating of Energy Storage System (ESS) for smoothing the wind generator output fluctuations. A determination of power rating of ESS unit which is sufficient for the smoothing control but as small as possible is very important. In this paper, a transfer function model is developed to obtain fast and easily the frequency response of power system including wind farms, and then, its accuracy is investigated. Finally the characteristic between the power rating of ESS and frequency deviation of the power system is analyzed and discussed.

Transient Stability Analysis of Wind Generator System with the Consideration of Multi-Mass Shaft Model

2005 International Conference on Power Electronics and Drives Systems

... logical pitch controller is presented which can enhance transient stability of wind generator... more ... logical pitch controller is presented which can enhance transient stability of wind generator. Moreover, that controller Keywords-Multi-Mass Shaft System; Pitch Controller; Power ... pitchcontroller is considered only in Case-IV. The simulation line. ...

Blade-Shaft Torsional Oscillation Minimization of Wind Turbine Generator System by Using STATCOM/ESS

2007 IEEE Lausanne Power Tech, 2007

ABSTRACT

A Novel Idea Generation Method, “SA method”

Affective and Pleasurable Design

“A technique for producing ideas” (James Webb Young,1940) has been a bible for advertising people... more “A technique for producing ideas” (James Webb Young,1940) has been a bible for advertising people since its publication. It says, “An idea is nothing more nor less than a new combination of old elements.''(P.15) It also says, “ An idea is a new combinations”.(P.20). But it never mentions how you can combine ideas with an excuse: “This part of the process is harder to describe in concrete terms because it goes on entirely inside your head.”(P.20) Another well known technique for idea producing is the “KJ method”(Jiro Kawakita,"Abduction”1967). It is an approach to find ideas by organizing ideas and it doesn't explain how you can produce ideas by combining elements.Now we are in an era where creation is the important drive force of economic activities in our society and creation is producing ideas. But still the process of producing ideas is in the veil. I am a film director, educator, as well as management consultant. Many of my students and clients need to find an idea with an objective such as career goal, new business idea, project idea. When I help them, I often deploy techniques I use for developing movie projects. I realized I always go through the same path with them. So I developed the “SA method” based on the path I always go through with my students or clients. I am now developing a software application based on the method.Combining two ideas is not so difficult but combining three ideas is extremely difficult. “SA method” helps people to produce ideas by combining three elements. “SA method” assumes an idea with three elements must be a “synthesis” produced by an aufheben in dialectic development with two elements. And each of three elements must be a synthesis produced in dialectic development with the rest respectively. When an idea is produced with three elements, the dialectic is revolved with the same three elements so that the idea is kneaded. “SA method” also has a process of quantifying it and describing it, which not only helps to ferment ideas in mind but also helps to select ideas at each proper timing. This selection also helps to separate the idea generation stage and the idea selection stage. According to my observation, people, who are not good at producing ideas, don’t know the importance of the separation. The SA method is a unique combination of practical and original use of dialectic development and Analytical Hierarchy processing.I conducted pilot tests with 35 undergraduate students at Utsunomiya University and 6 undergraduate students at Chuo University in November of 2021 to find their career goal using the SA method. During the trial, some people had difficulties producing 25 ideas. There may be some reasons such as not being accustomed to generating ideas and “SA method”, and 25 was an unnecessarily large number. Also they didn’t have enough time to search for information about their career development.We are now considering how to refine the methodology. Also, we have started to develop a Web based tool or PC application to work with the “SA method” visually. I would like to conduct further research projects such as comparing “SA method” with “KJ method” while refining the method.

Monsters Are Attacking Tokyo: The Incredible World of Japanese Fantasy Films

Stabilization of Power System by Virtual Inertia Control of Adjustable Speed Synchronous Condenser

In recent years, renewable energy has attracted attention as a measure against global environment... more In recent years, renewable energy has attracted attention as a measure against global environmental problems, and along with that, the penetration of inverter based power sources has been increasing. However, since there is no inertial force in the inverter based power supply, if the penetration is expanded, the inertial force of the entire power system will decrease and thus the stability may decrease. Therefore, a new virtual inertia control method using an adjustable speed synchronous condenser (ASSC) is proposed in this paper. The proposed virtual inertia control method, which is designed based on the Fuzzy Logic theory can contribute to prevent the decrease of the inertial force of the power system. It can improve the stability of the power system when the Squirrel Cage Induction Generator (SCIG) based Wind Farm (WF) trips. Performance of the proposed system is evaluated by using a model system consisting of conventional Synchronous Generators (SGs), ASSC and WF. From the analysis results, it can be confirmed that the proposed method improves the stability of the system.

Voltage control and virtual synchronous generator control of HVDC interconnection line for improving stability of power system including large‐scale wind farm

Iet Generation Transmission & Distribution, Jul 4, 2021

Large-scale integration of renewable energy sources (RESs) such as wind power can impact on the e... more Large-scale integration of renewable energy sources (RESs) such as wind power can impact on the existing power system's stability. For example, there is a possibility that the wind farm (WF) cannot be maintained stable and then it is disconnected from the grid when the instantaneous voltage sag caused by a grid disturbance occurs. Moreover, the increasing integration of RESs in the power system can reduce the number of conventional synchronous generators (SGs) connected to the grid, and lead to a reduction of system inertia in the grid. The system inertia reduction can cause larger and faster frequency fluctuations during the transient period. Hence, this paper proposes a new control strategy composed of the voltage control for suppressing the voltage sag and the virtual synchronous generator (VSG) control based on the proportional-integral-differential (PID) fuzzy logic control (FLC) for maintaining the frequency stability which is performed by high voltage direct current (HVDC) interconnection line. The aim of the new control strategy is to improve the stability of the entire power system with large-scale integration of RESs. The effectiveness of the proposed strategy is confirmed through the simulation analyses by PSCAD/EMTDC.

Ieej Transactions on Power and Energy, 2005

Recently, wind power generation is increasing in the world. In the wind power stations, induction... more Recently, wind power generation is increasing in the world. In the wind power stations, induction machines are mostly used as generators. Since induction generators have a stability problem similar to the transient stability of synchronous machines, it is important to analyze the transient stability of power systems including wind generators. Although there have been some reports analyzing the transient stability problem, wind turbine and wind generator are, in most cases, modeled as one mass shaft system having total inertia constant. This paper presents simulation analyses of transient stability of power system including induction generator which is expressed by a two-mass shaft model and analyzes an effect of shaft system modeling on the transient stability characteristics. Simulations are performed by PSCAD/EMTDC in this study.

Stability Improvement of Power System with a Wind Farm by the Virtual Synchronous Generator Control of Battery

IEEJ Transactions on Power and Energy

Stability Enhancement of Power System by Cooperative Virtual Synchronous Generator Control between ASSC and LFC Hydro Power Plant

IEEJ Transactions on Power and Energy

Stability Enhancement of Power System including Wind Farm by Voltage Control and Virtual Synchronous Generator Control

2021 2nd International Conference on Robotics, Electrical and Signal Processing Techniques (ICREST), 2021

A huge number of renewable energy sources (RESs) has been connected to the existing power system,... more A huge number of renewable energy sources (RESs) has been connected to the existing power system, which has impact on the power system stability. Especially, the power system with large-scale wind farm (WF) may not be maintained stable during transient period due to the voltage dip caused by a network fault. To solve the power system stability issue, a new cooperative control method composed of the voltage control and the PID Fuzzy Logic Control (FLC) based Virtual Synchronous Generator (VSG) control by High Voltage Direct Current (HVDC) transmission line, a battery, and the LFC hydro power plant is proposed. To confirm the effectiveness of this proposed strategy, power system stability analyses are implemented on PSCAD/EMTDC.

Stabilization of Power System by Virtual Inertia Control of Adjustable Speed Synchronous Condenser

2021 2nd International Conference on Robotics, Electrical and Signal Processing Techniques (ICREST), 2021

In recent years, renewable energy has attracted attention as a measure against global environment... more In recent years, renewable energy has attracted attention as a measure against global environmental problems, and along with that, the penetration of inverter based power sources has been increasing. However, since there is no inertial force in the inverter based power supply, if the penetration is expanded, the inertial force of the entire power system will decrease and thus the stability may decrease. Therefore, a new virtual inertia control method using an adjustable speed synchronous condenser (ASSC) is proposed in this paper. The proposed virtual inertia control method, which is designed based on the Fuzzy Logic theory can contribute to prevent the decrease of the inertial force of the power system. It can improve the stability of the power system when the Squirrel Cage Induction Generator (SCIG) based Wind Farm (WF) trips. Performance of the proposed system is evaluated by using a model system consisting of conventional Synchronous Generators (SGs), ASSC and WF. From the analysis results, it can be confirmed that the proposed method improves the stability of the system.

A Consideration on the Stabilization of Wind Generator by Pitch Control System

A new concept of welfare psychology

International Journal of Psychology, 2016

Voltage control and virtual synchronous generator control of HVDC interconnection line for improving stability of power system including large‐scale wind farm

IET Generation, Transmission & Distribution, 2021

Large-scale integration of renewable energy sources (RESs) such as wind power can impact on the e... more Large-scale integration of renewable energy sources (RESs) such as wind power can impact on the existing power system's stability. For example, there is a possibility that the wind farm (WF) cannot be maintained stable and then it is disconnected from the grid when the instantaneous voltage sag caused by a grid disturbance occurs. Moreover, the increasing integration of RESs in the power system can reduce the number of conventional synchronous generators (SGs) connected to the grid, and lead to a reduction of system inertia in the grid. The system inertia reduction can cause larger and faster frequency fluctuations during the transient period. Hence, this paper proposes a new control strategy composed of the voltage control for suppressing the voltage sag and the virtual synchronous generator (VSG) control based on the proportional-integral-differential (PID) fuzzy logic control (FLC) for maintaining the frequency stability which is performed by high voltage direct current (HVDC) interconnection line. The aim of the new control strategy is to improve the stability of the entire power system with large-scale integration of RESs. The effectiveness of the proposed strategy is confirmed through the simulation analyses by PSCAD/EMTDC.

Proceedings for Annual Meeting of The Japanese Pharmacological Society, 2021

Although monoamine-based pharmacological drugs revolutionized the treatment of major depressive d... more Although monoamine-based pharmacological drugs revolutionized the treatment of major depressive disorder, about one third of patients experience treatment-resistant depression. Thus, development of antidepressant with novel mechanism is required. In this study, we investigated the involvement of microsomal prostaglandin E synthase-1 (mPGES-1), a terminal inducible enzyme for PGE 2 synthesis, in acute restraint stress (RS: 6 hr) and social defeat stress (SDS: 1 day). mPGES-1 mRNA was significantly increased after RS. Induction of mPGES-1 protein was observed in neurons in the frontal cortex (FC). PGE 2 in FC was also significantly upregulated in wild-type (WT) mice, but not in mPGES-1 knockout (ES1KO) mice. The inflammatory responses, such as increases in GFAP and TNF-α, observed after RS in ES1KO were significantly less than those in WT. After RS, there were no significant differences between WT and ES1KO in open field test (OFT), forced swimming test, elevated plus maze test (EPM) and marble burying test. On the other hand, in sucrose preference test, the ratio of sucrose intake after RS in WT was significantly less than that in ES1KO. In acute SDS model, social avoidance behavior was significantly observed after SDS. At the same time, upregulation of mPGES-1 was also observed in FC, amygdala and ventral tegmental area. Taken together, these results suggest that mPGES-1 is induced by acute stress in FC, and then contributes to brain inflammation and anhedonia through PGE 2 production. Thus, mPGSE-1 may be a promising novel therapeutic target for depression.

Virtual Synchronous Generator Control of Power System including Large-scale Wind Farm by Cooperative Operation between Battery and LFC Hydro Power Plant

IEEJ Transactions on Power and Energy, 2020

Journal of Power and Energy Engineering, 2020

Recently, introduction of renewable energy sources like wind power generation and photovoltaic po... more Recently, introduction of renewable energy sources like wind power generation and photovoltaic power generation has been increasing from the viewpoint of environmental problems. However, renewable energy power supplies have unstable output due to the influence of weather conditions such as wind speed variations, which may cause fluctuations of voltage and frequency in the power system. This paper proposes fuzzy PD based virtual inertia control system to decrease frequency fluctuations in power system caused by fluctuating output of renewable energy sources. The proposed new method is based on the coordinated control of HVDC interconnection line and battery, and energy balancing control is also incorporated in it. Finally, it is concluded that the proposed system is very effective for suppressing the frequency fluctuations of the power system due to the large-scale wind power generation and solar power generation and also for keeping the energy balancing in the HVDC transmission line.

Journal of international Conference on Electrical Machines and Systems, 2013

In this paper an application of centralized pitch angle controller for fixed speed wind turbines ... more In this paper an application of centralized pitch angle controller for fixed speed wind turbines based wind farm to mitigate load frequency fluctuation is presented. Reference signal for the pitch angle of each wind turbine is calculated by using proposed centralized control system based on wind speed information. The wind farm in the model system is connected to a multi machine power system which is composed of 4 synchronous generators and a load. Simulation analyses have been carried out to investigate the performance of the controller using real wind speed data. It is concluded that the load frequency of the system can be controlled smoothly.

単地点での日射量時系列に基づく10km四方内の空間平均日射量時系列の生成および変動幅出現頻度による評価

IEEJ Transactions on Power and Energy, 2014

風力発電機出力平滑化用エネルギー貯蔵装置の定格決定に関する検討

IEEJ Transactions on Power and Energy, 2012

ABSTRACT This paper proposes an evaluation method for determining the power rating of Energy Stor... more ABSTRACT This paper proposes an evaluation method for determining the power rating of Energy Storage System (ESS) for smoothing the wind generator output fluctuations. A determination of power rating of ESS unit which is sufficient for the smoothing control but as small as possible is very important. In this paper, a transfer function model is developed to obtain fast and easily the frequency response of power system including wind farms, and then, its accuracy is investigated. Finally the characteristic between the power rating of ESS and frequency deviation of the power system is analyzed and discussed.

Transient Stability Analysis of Wind Generator System with the Consideration of Multi-Mass Shaft Model

2005 International Conference on Power Electronics and Drives Systems

... logical pitch controller is presented which can enhance transient stability of wind generator... more ... logical pitch controller is presented which can enhance transient stability of wind generator. Moreover, that controller Keywords-Multi-Mass Shaft System; Pitch Controller; Power ... pitchcontroller is considered only in Case-IV. The simulation line. ...

Blade-Shaft Torsional Oscillation Minimization of Wind Turbine Generator System by Using STATCOM/ESS

2007 IEEE Lausanne Power Tech, 2007

ABSTRACT