In China, regions with abundant wind energy resources are generally located at the end of power grids. The power grid architecture in these regions is typically not sufficiently strong, and the energy structure is rel...In China, regions with abundant wind energy resources are generally located at the end of power grids. The power grid architecture in these regions is typically not sufficiently strong, and the energy structure is relatively simple. Thus, connecting large-capacity wind power units complicates the peak load regulation and stable operation of the power grids in these regions. Most wind turbines use power electronic converter technology, which affects the safety and stability of the power grid differently compared with conventional synchronous generators. Furthermore, fluctuations in wind power cause fluctuations in the output of wind farms, making it difficult to create and implement suitable power generation plans for wind farms. The generation technology and grid connection scheme for wind power and conventional thermal power generation differ considerably. Moreover, the active and reactive power control abilities of wind turbines are weaker than those of thermal power units, necessitating additional equipment to control wind turbines. Hence, to address the aforementioned issues with large-scale wind power generation, this study analyzes the differences between the grid connection and collection strategies for wind power bases and thermal power plants. Based on this analysis, the differences in the power control modes of wind power and thermal power are further investigated. Finally, the stability of different control modes is analyzed through simulation. The findings can be beneficial for the planning and development of large-scale wind power generation farms.展开更多
Libya is an oil exporting country located in the middle of the North Africa. Exporting oil is the major income resource for the economics of the country. Al-Zawea refinery is one of the oil refineries in Libya. It is ...Libya is an oil exporting country located in the middle of the North Africa. Exporting oil is the major income resource for the economics of the country. Al-Zawea refinery is one of the oil refineries in Libya. It is the largest refinery in the region. The refinery located in the Mediterranean coast. Electricity is the main sector in the refinery to produce and export oil. This paper discusses the possibility of the penetration of the renewable energy (wind) generated electricity into the refinery power system. Although, renewable energy application in Libya was started in the middle of the seventies, it has still not found its way into industry sector. This study proposes the possible impacts of renewable (wind) energy system integration on the Al-Zawea refinery electric grid to satisfy the refinery load demand.展开更多
The energy loss of the power grid is one of the key factors affecting the economic operation of power systems. How to calculate the electric energy consumption accurately will have a great influence on the planning, o...The energy loss of the power grid is one of the key factors affecting the economic operation of power systems. How to calculate the electric energy consumption accurately will have a great influence on the planning, operation and management of the power grid. Currently there is a mountain of theoretical methods to calculate the line loss of the power system. However, these methods have some limitation, such as less considering the volatility of wind power resources. This paper presents an improved method to calculate the energy loss of wind power generation, considering the fluctuations of wind power generation. First, data are collected to obtain the curve of the typical daily expected output of wind farms for one month. Second, the curve of the typical daily expected output are corrected by the average electricity and the shape factor to obtain the curve of the typical daily equivalent output of wind farms for one month. Finally, the power flow is calculated by using typical daily equivalent output curve to describe the energy loss for one month. The results in the 110 kV main network show that the method is feasible.展开更多
Application of Distributed Generation (DG) to supply the demands of a diverse customer base plays a vital role in the renewable energy environment. Various DG technologies are being integrated into power systems to pr...Application of Distributed Generation (DG) to supply the demands of a diverse customer base plays a vital role in the renewable energy environment. Various DG technologies are being integrated into power systems to provide alterna-tives to energy sources and to improve reliability of the system. Power Evacuation from these remotely located DG’s remains a major concern for the power utilities these days. The main cause of concern regarding evacuation is con-sumption of reactive power for excitation by Induction Generators (IG) used in wind power production which affects the power system in variety of ways. This paper deals with the issues related to reactive power consumption by Induc-tion generators during power evacuation. Induction generator based wind turbine model using MATLAB/SIMULINK is simulated and its impact on the grid is observed. The simulated results are analyzed and validated with the real time results for the system considered. A wind farm is also modeled and simulations are carried out to study the various im-pacts it has on the grid &nearby wind turbines during Islanding and system event especially on 3-Phase to ground fault.展开更多
This paper presents aspects of study and simulation approach for planned wind power projects in Kosovo Power System in relation with Grid Code requirements. All generators, connected to the Kosovo Transmission System ...This paper presents aspects of study and simulation approach for planned wind power projects in Kosovo Power System in relation with Grid Code requirements. All generators, connected to the Kosovo Transmission System are required to comply with the Grid Code. The Grid Code was originally developed with conventional synchronous generators. Since Wind Turbine Generators don’t have the same characteristics as synchronous generators, it was considered appropriate to develop a new set of Grid Code provisions specifically for Wind Farm Power Stations in relation with specific characteristic of Kosovo Power System. With high excepted penetration of wind power, a simultaneous loss of Wind Farms generation will put in the risk the security and reliability of Power System. Therefore, the main requirements for Wind farm power stations concern the fault ride through capability, frequency operation range, and reactive power capability of wind turbines. In the case of grid faults wind turbines have to supply a definite reactive power depending on the instantaneous voltage level of connection point and they must return quickly to normal operation.展开更多
Modeling of photovoltaic (PV) and wind farms (WF) stations to take into account these renewable energies into the power flow formulation are summarized. A strategy based on multi objective optimization in order to all...Modeling of photovoltaic (PV) and wind farms (WF) stations to take into account these renewable energies into the power flow formulation are summarized. A strategy based on multi objective optimization in order to allocate PV and WF power into electrical power system is proposed. It is assumed that there are a reduced number of choices to allocate the stations. The algorithm is applied to the 39-bus test power system. The results show that the proposed algorithm is capable of optimal placement of renewable units.展开更多
The objective of this study is to develop a wind farm placement and investment methodology based on a linear optimization procedure.This problem has a major significance for the investment success for the projects of ...The objective of this study is to develop a wind farm placement and investment methodology based on a linear optimization procedure.This problem has a major significance for the investment success for the projects of renewable energy such as wind power.In this study,a mesoscale approach is adopted whereby the wind farm location is investigated in comparison with a microscale approach where the location of each individual turbine is optimized.Specifical study focuses on the placement of a wind farm by economical optimization constrained by the power system,wind resources,and techno-economics.Linear optimization is introduced in this context at the power system which is constrained by wind farm planning.展开更多
基金This work was supported by National Key Research and Development Program of China(2018YFB0904000).
文摘In China, regions with abundant wind energy resources are generally located at the end of power grids. The power grid architecture in these regions is typically not sufficiently strong, and the energy structure is relatively simple. Thus, connecting large-capacity wind power units complicates the peak load regulation and stable operation of the power grids in these regions. Most wind turbines use power electronic converter technology, which affects the safety and stability of the power grid differently compared with conventional synchronous generators. Furthermore, fluctuations in wind power cause fluctuations in the output of wind farms, making it difficult to create and implement suitable power generation plans for wind farms. The generation technology and grid connection scheme for wind power and conventional thermal power generation differ considerably. Moreover, the active and reactive power control abilities of wind turbines are weaker than those of thermal power units, necessitating additional equipment to control wind turbines. Hence, to address the aforementioned issues with large-scale wind power generation, this study analyzes the differences between the grid connection and collection strategies for wind power bases and thermal power plants. Based on this analysis, the differences in the power control modes of wind power and thermal power are further investigated. Finally, the stability of different control modes is analyzed through simulation. The findings can be beneficial for the planning and development of large-scale wind power generation farms.
文摘Libya is an oil exporting country located in the middle of the North Africa. Exporting oil is the major income resource for the economics of the country. Al-Zawea refinery is one of the oil refineries in Libya. It is the largest refinery in the region. The refinery located in the Mediterranean coast. Electricity is the main sector in the refinery to produce and export oil. This paper discusses the possibility of the penetration of the renewable energy (wind) generated electricity into the refinery power system. Although, renewable energy application in Libya was started in the middle of the seventies, it has still not found its way into industry sector. This study proposes the possible impacts of renewable (wind) energy system integration on the Al-Zawea refinery electric grid to satisfy the refinery load demand.
文摘The energy loss of the power grid is one of the key factors affecting the economic operation of power systems. How to calculate the electric energy consumption accurately will have a great influence on the planning, operation and management of the power grid. Currently there is a mountain of theoretical methods to calculate the line loss of the power system. However, these methods have some limitation, such as less considering the volatility of wind power resources. This paper presents an improved method to calculate the energy loss of wind power generation, considering the fluctuations of wind power generation. First, data are collected to obtain the curve of the typical daily expected output of wind farms for one month. Second, the curve of the typical daily expected output are corrected by the average electricity and the shape factor to obtain the curve of the typical daily equivalent output of wind farms for one month. Finally, the power flow is calculated by using typical daily equivalent output curve to describe the energy loss for one month. The results in the 110 kV main network show that the method is feasible.
文摘Application of Distributed Generation (DG) to supply the demands of a diverse customer base plays a vital role in the renewable energy environment. Various DG technologies are being integrated into power systems to provide alterna-tives to energy sources and to improve reliability of the system. Power Evacuation from these remotely located DG’s remains a major concern for the power utilities these days. The main cause of concern regarding evacuation is con-sumption of reactive power for excitation by Induction Generators (IG) used in wind power production which affects the power system in variety of ways. This paper deals with the issues related to reactive power consumption by Induc-tion generators during power evacuation. Induction generator based wind turbine model using MATLAB/SIMULINK is simulated and its impact on the grid is observed. The simulated results are analyzed and validated with the real time results for the system considered. A wind farm is also modeled and simulations are carried out to study the various im-pacts it has on the grid &nearby wind turbines during Islanding and system event especially on 3-Phase to ground fault.
文摘This paper presents aspects of study and simulation approach for planned wind power projects in Kosovo Power System in relation with Grid Code requirements. All generators, connected to the Kosovo Transmission System are required to comply with the Grid Code. The Grid Code was originally developed with conventional synchronous generators. Since Wind Turbine Generators don’t have the same characteristics as synchronous generators, it was considered appropriate to develop a new set of Grid Code provisions specifically for Wind Farm Power Stations in relation with specific characteristic of Kosovo Power System. With high excepted penetration of wind power, a simultaneous loss of Wind Farms generation will put in the risk the security and reliability of Power System. Therefore, the main requirements for Wind farm power stations concern the fault ride through capability, frequency operation range, and reactive power capability of wind turbines. In the case of grid faults wind turbines have to supply a definite reactive power depending on the instantaneous voltage level of connection point and they must return quickly to normal operation.
文摘Modeling of photovoltaic (PV) and wind farms (WF) stations to take into account these renewable energies into the power flow formulation are summarized. A strategy based on multi objective optimization in order to allocate PV and WF power into electrical power system is proposed. It is assumed that there are a reduced number of choices to allocate the stations. The algorithm is applied to the 39-bus test power system. The results show that the proposed algorithm is capable of optimal placement of renewable units.
基金supported by TUBITAK Scholarship(No.B.14.2.TBT.0.06.01-214-6041)Yildiz Technical University Scientific Project Coordination Fund(No.2012-04-02-DOP04)。
文摘The objective of this study is to develop a wind farm placement and investment methodology based on a linear optimization procedure.This problem has a major significance for the investment success for the projects of renewable energy such as wind power.In this study,a mesoscale approach is adopted whereby the wind farm location is investigated in comparison with a microscale approach where the location of each individual turbine is optimized.Specifical study focuses on the placement of a wind farm by economical optimization constrained by the power system,wind resources,and techno-economics.Linear optimization is introduced in this context at the power system which is constrained by wind farm planning.