Out-of-step oscillation is a very destructive physical phenomenon in power system, which could directly cause big blackout accompanied by serious sociology-economic impacts. Out-of-step splitting control is an indispe...Out-of-step oscillation is a very destructive physical phenomenon in power system, which could directly cause big blackout accompanied by serious sociology-economic impacts. Out-of-step splitting control is an indispensable means, which could protect the system from major shocks of out-of-step oscillation. After years of development, it has achieved certain amount of research results. Have the existing methods been able to meet the requirements of out-of-step splitting? What improvements are needed? Under this background, this review is written. It combs the development of out-of-step splitting control technologies and analyzes the technical routes and characteristics of different methods. It points out the contradiction between rapidity and optimality is the biggest technical problem, existing in both the traditional local measurement based out-of-step splitting protection and the wide-area information based out-of-step splitting protection. It further points out that the advantages of the two types of protections can be combined with the unique physical characteristics of the out-of-step center to form a more advantageous splitting strategy. Besides, facing the fact of large-scale renewable energy access to power grid in recent years, this review also analyzes the challenges brought by it and provides some corresponding suggestions. It is hoped to provide some guidance for the subsequent research work.展开更多
Human development is inherently connected with availability of water and energy.Energy production requires water,whereas water treatment needs energy.On the other hand,microbial fuel cell has capability to produce ene...Human development is inherently connected with availability of water and energy.Energy production requires water,whereas water treatment needs energy.On the other hand,microbial fuel cell has capability to produce energy and water simultaneously from waste water or organic matter.In this paper,first principle-based model of variable volume microbial fuel cell is simulated.Hydraulic retention time is selected as the manipulated variable using the study of steady state and dynamic responses.Classical PI and model predictive control strategies are developed for controlling the produced power from the cell,and its performance is tested for servo problem.Settling time for positive and negative set points is found to be 126 and 889 h in case of classical PI and 120 and 750 h in case of linear MPC,respectively along with large increase(three times order of magnitude)in working volume for negative set point.These control challenges are overcome by using split range controller with variable and constant volume microbial fuel cells.The settling time for negative set point is found to be 49 and 21 h for classical PI and linear MPC schemes,respectively,which is significantly lower than using only variable volume microbial fuel cell.Also,there is no increase in the working volume of the constant volume microbial fuel cell.Hence,operating range of the microbial fuel cell is enhanced using split range controller.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.62273207,61821004,62350083,62192755)the Future Young Scholars Program of Shandong University,China.
文摘Out-of-step oscillation is a very destructive physical phenomenon in power system, which could directly cause big blackout accompanied by serious sociology-economic impacts. Out-of-step splitting control is an indispensable means, which could protect the system from major shocks of out-of-step oscillation. After years of development, it has achieved certain amount of research results. Have the existing methods been able to meet the requirements of out-of-step splitting? What improvements are needed? Under this background, this review is written. It combs the development of out-of-step splitting control technologies and analyzes the technical routes and characteristics of different methods. It points out the contradiction between rapidity and optimality is the biggest technical problem, existing in both the traditional local measurement based out-of-step splitting protection and the wide-area information based out-of-step splitting protection. It further points out that the advantages of the two types of protections can be combined with the unique physical characteristics of the out-of-step center to form a more advantageous splitting strategy. Besides, facing the fact of large-scale renewable energy access to power grid in recent years, this review also analyzes the challenges brought by it and provides some corresponding suggestions. It is hoped to provide some guidance for the subsequent research work.
文摘Human development is inherently connected with availability of water and energy.Energy production requires water,whereas water treatment needs energy.On the other hand,microbial fuel cell has capability to produce energy and water simultaneously from waste water or organic matter.In this paper,first principle-based model of variable volume microbial fuel cell is simulated.Hydraulic retention time is selected as the manipulated variable using the study of steady state and dynamic responses.Classical PI and model predictive control strategies are developed for controlling the produced power from the cell,and its performance is tested for servo problem.Settling time for positive and negative set points is found to be 126 and 889 h in case of classical PI and 120 and 750 h in case of linear MPC,respectively along with large increase(three times order of magnitude)in working volume for negative set point.These control challenges are overcome by using split range controller with variable and constant volume microbial fuel cells.The settling time for negative set point is found to be 49 and 21 h for classical PI and linear MPC schemes,respectively,which is significantly lower than using only variable volume microbial fuel cell.Also,there is no increase in the working volume of the constant volume microbial fuel cell.Hence,operating range of the microbial fuel cell is enhanced using split range controller.
