A parallel hybrid linear solver based on the Schur complement method has the potential to balance the robustness of direct solvers with the efficiency of preconditioned iterative solvers.However,when solving large-sca...A parallel hybrid linear solver based on the Schur complement method has the potential to balance the robustness of direct solvers with the efficiency of preconditioned iterative solvers.However,when solving large-scale highly-indefinite linear systems,this hybrid solver often suffers from either slow convergence or large memory requirements to solve the Schur complement systems.To overcome this challenge,we in this paper discuss techniques to preprocess the Schur complement systems in parallel. Numerical results of solving large-scale highly-indefinite linear systems from various applications demonstrate that these techniques improve the reliability and performance of the hybrid solver and enable efficient solutions of these linear systems on hundreds of processors,which was previously infeasible using existing state-of-the-art solvers.展开更多
This paper describes a design method and construction of a PV hybrid system for household electrification in remote area which has typical important electrical loads for daily life such as television, refrigerator, el...This paper describes a design method and construction of a PV hybrid system for household electrification in remote area which has typical important electrical loads for daily life such as television, refrigerator, electric fan, coffee maker, and radio. The paper presents the design method which is a short and correct method for the PV Hybrid system design. The result of the proposed design method is finally simulated by Homer software to optimize and prove the result. From the simulation, the output shows that the proposed method is proper for using to design the sizing of PV hybrid system. After the design, a PV hybrid system is constructed accordingly to the system design. A PV hybrid prototype is constructed as a small house which is specially constructed for demonstration of the proposed system. The PV hybrid system therefore has the size of PV 1.8 kWp, battery 20 kWh, and diesel generator 3 kW. After a long implementation of the system, the results of monitored data show that the designed PV hybrid system can deliver the power to the house continually 24 hours as it is originally designed. This can ensure that the proposed method of PV hybrid system design is correct and can be used for design the PV hybrid system for electrical utility in the remote area where has no an electric grid.展开更多
With large-scale use of kinds of motors, oilfield drilling electrical system always accompanied by serious power quality problem, including reactive current, harmonics current and grid voltage distortion, which would ...With large-scale use of kinds of motors, oilfield drilling electrical system always accompanied by serious power quality problem, including reactive current, harmonics current and grid voltage distortion, which would greatly threaten the safety and proper working of the whole system. This paper focuses on a power quality improvement project to solve these problems. A hybrid compensating scheme, including an active compensator and a passive compensator, is carried out. Because of the specificity of oilfield drilling electrical system, compensators are redesigned against features of this application background. And then the current detection point arrangement of this hybrid system is also taken into consideration to build the whole system much more effective and reliable. Now the improvement project is already implemented in application field, and the power quality of the system is greatly improved.展开更多
基金supported in part by the Director,Office of Science,Office of Advanced Scientific Computing Research,of the U.S.Department of Energy under Contract No.DE-AC02-05CH11231.
文摘A parallel hybrid linear solver based on the Schur complement method has the potential to balance the robustness of direct solvers with the efficiency of preconditioned iterative solvers.However,when solving large-scale highly-indefinite linear systems,this hybrid solver often suffers from either slow convergence or large memory requirements to solve the Schur complement systems.To overcome this challenge,we in this paper discuss techniques to preprocess the Schur complement systems in parallel. Numerical results of solving large-scale highly-indefinite linear systems from various applications demonstrate that these techniques improve the reliability and performance of the hybrid solver and enable efficient solutions of these linear systems on hundreds of processors,which was previously infeasible using existing state-of-the-art solvers.
文摘This paper describes a design method and construction of a PV hybrid system for household electrification in remote area which has typical important electrical loads for daily life such as television, refrigerator, electric fan, coffee maker, and radio. The paper presents the design method which is a short and correct method for the PV Hybrid system design. The result of the proposed design method is finally simulated by Homer software to optimize and prove the result. From the simulation, the output shows that the proposed method is proper for using to design the sizing of PV hybrid system. After the design, a PV hybrid system is constructed accordingly to the system design. A PV hybrid prototype is constructed as a small house which is specially constructed for demonstration of the proposed system. The PV hybrid system therefore has the size of PV 1.8 kWp, battery 20 kWh, and diesel generator 3 kW. After a long implementation of the system, the results of monitored data show that the designed PV hybrid system can deliver the power to the house continually 24 hours as it is originally designed. This can ensure that the proposed method of PV hybrid system design is correct and can be used for design the PV hybrid system for electrical utility in the remote area where has no an electric grid.
文摘With large-scale use of kinds of motors, oilfield drilling electrical system always accompanied by serious power quality problem, including reactive current, harmonics current and grid voltage distortion, which would greatly threaten the safety and proper working of the whole system. This paper focuses on a power quality improvement project to solve these problems. A hybrid compensating scheme, including an active compensator and a passive compensator, is carried out. Because of the specificity of oilfield drilling electrical system, compensators are redesigned against features of this application background. And then the current detection point arrangement of this hybrid system is also taken into consideration to build the whole system much more effective and reliable. Now the improvement project is already implemented in application field, and the power quality of the system is greatly improved.
