In this paper, Power System Stabilizer (PSS) and Automatic Voltage Regulator (AVR) are coordinated to improve the transient stability of generator in power system. Coordinated design problem of AVR and PSS is formulat...In this paper, Power System Stabilizer (PSS) and Automatic Voltage Regulator (AVR) are coordinated to improve the transient stability of generator in power system. Coordinated design problem of AVR and PSS is formulated as an optimization problem. Particle Swarm Optimization (PSO) technique is an advanced robust search method by the swarming or cooperative behavior of biological populations mechanism. The performance of PSO has been certified in solution of highly non-linear objectives. Thus, PSO technique has been employed to optimize the parameters of PSS and AVR in order to reduce the power system oscillations during the load changing conditions in single-machine, infinite-bus power system. The results of nonlinear simulation suggest that, by coordinated design of AVR and PSS based on PSO technique power system oscillations are exceptionally damped. Correspondingly, it’s shown that power system stability is superiorly enhanced than the uncoordinated designed of the PSS and the AVR controllers.展开更多
In the subway power dispatching monitoring system, the actual power dispatching workstation and the virtual power supply system are combined to realize the simulation of the subway power dispatching monitoring system....In the subway power dispatching monitoring system, the actual power dispatching workstation and the virtual power supply system are combined to realize the simulation of the subway power dispatching monitoring system. At the same time, the system is universal and can be popularized and applied to the operation and control of other subway line power supply systems. At present, the system has been used in the operation, control and monitoring of subway power supply system by subway power dispatchers which has been mature in various cities, which can effectively improve the work efficiency of subway power dispatchers and meet the actual application needs. It is of great practical significance to establish a complete and systematic subway power dispatching and monitoring system.展开更多
Fire is one of the most common accidents in daily life. In the process of fire accident prevention, monitoring and management, attention should be paid not only to the timeliness of automatic fire alarm equipment, but...Fire is one of the most common accidents in daily life. In the process of fire accident prevention, monitoring and management, attention should be paid not only to the timeliness of automatic fire alarm equipment, but also to the danger of fire caused by building power distribution facilities. Therefore, in the process of design and construction of building electrical systems, We should not only pay attention to the design and installation of the automatic fire alarm system, but also pay attention to the fire protection power distribution system, so that the building electrical system can give full play to its functions, improve the utilization rate of building electrical facilities, and enable the building electrical system to play a good role in the process of fire accident prevention and alarm. This paper will focus on the topic of fire protection power distribution system design and automatic fire alarm system design in the building electrical system.展开更多
The results are presented of an experimental investigation of heat transfer in an air-liquid cooling system for a Switch-Mode Power Supply (SMPS) for TV digital power amplifiers. Since these SMPSs are characterized by...The results are presented of an experimental investigation of heat transfer in an air-liquid cooling system for a Switch-Mode Power Supply (SMPS) for TV digital power amplifiers. Since these SMPSs are characterized by high power and high compactness, thereby making the standard cooling techniques difficult to be used, a new cooling system is developed, using water and air as the cooling media. The active components (MOSFETs) are cooled with a liquid cold-plate, the passive ones (condensers, transformers, coils) with an air flow, in turn cooled by the cold-plate. By inserting the cooling system in an experimental tool where it is possible to control the cooling water, measurements are made of temperature in the significant points of the SMPS. The electric efficiency is also measured. The evaluation of the thermal performance of this cooling system is useful in order to limit its maximum operational temperature. The efficacy of the cooling system is demonstrated;the trends of efficiency and power dissipation are evidenced.展开更多
Besides pumped hydropower, Compressed Air Energy Storage (CAES) is the other solution for large energy storage capacity. It can balance fluctuations in supply and demand of electricity. CAES is essential part of smart...Besides pumped hydropower, Compressed Air Energy Storage (CAES) is the other solution for large energy storage capacity. It can balance fluctuations in supply and demand of electricity. CAES is essential part of smart power grids. Linked with the flow structure and dynamic characteristic of electricity generation subsystem and its components, a simulation model is proposed. Thermo-dynamical performance on off-design conditions have been analyzed with constant air mass flux and constant gas combustion temperature. Some simulation diagrams of curve are plotted too. The contrast of varied operation mode thermal performance is made between CAES power plant and simple gas turbine power plant.展开更多
文摘In this paper, Power System Stabilizer (PSS) and Automatic Voltage Regulator (AVR) are coordinated to improve the transient stability of generator in power system. Coordinated design problem of AVR and PSS is formulated as an optimization problem. Particle Swarm Optimization (PSO) technique is an advanced robust search method by the swarming or cooperative behavior of biological populations mechanism. The performance of PSO has been certified in solution of highly non-linear objectives. Thus, PSO technique has been employed to optimize the parameters of PSS and AVR in order to reduce the power system oscillations during the load changing conditions in single-machine, infinite-bus power system. The results of nonlinear simulation suggest that, by coordinated design of AVR and PSS based on PSO technique power system oscillations are exceptionally damped. Correspondingly, it’s shown that power system stability is superiorly enhanced than the uncoordinated designed of the PSS and the AVR controllers.
文摘In the subway power dispatching monitoring system, the actual power dispatching workstation and the virtual power supply system are combined to realize the simulation of the subway power dispatching monitoring system. At the same time, the system is universal and can be popularized and applied to the operation and control of other subway line power supply systems. At present, the system has been used in the operation, control and monitoring of subway power supply system by subway power dispatchers which has been mature in various cities, which can effectively improve the work efficiency of subway power dispatchers and meet the actual application needs. It is of great practical significance to establish a complete and systematic subway power dispatching and monitoring system.
文摘Fire is one of the most common accidents in daily life. In the process of fire accident prevention, monitoring and management, attention should be paid not only to the timeliness of automatic fire alarm equipment, but also to the danger of fire caused by building power distribution facilities. Therefore, in the process of design and construction of building electrical systems, We should not only pay attention to the design and installation of the automatic fire alarm system, but also pay attention to the fire protection power distribution system, so that the building electrical system can give full play to its functions, improve the utilization rate of building electrical facilities, and enable the building electrical system to play a good role in the process of fire accident prevention and alarm. This paper will focus on the topic of fire protection power distribution system design and automatic fire alarm system design in the building electrical system.
文摘The results are presented of an experimental investigation of heat transfer in an air-liquid cooling system for a Switch-Mode Power Supply (SMPS) for TV digital power amplifiers. Since these SMPSs are characterized by high power and high compactness, thereby making the standard cooling techniques difficult to be used, a new cooling system is developed, using water and air as the cooling media. The active components (MOSFETs) are cooled with a liquid cold-plate, the passive ones (condensers, transformers, coils) with an air flow, in turn cooled by the cold-plate. By inserting the cooling system in an experimental tool where it is possible to control the cooling water, measurements are made of temperature in the significant points of the SMPS. The electric efficiency is also measured. The evaluation of the thermal performance of this cooling system is useful in order to limit its maximum operational temperature. The efficacy of the cooling system is demonstrated;the trends of efficiency and power dissipation are evidenced.
文摘Besides pumped hydropower, Compressed Air Energy Storage (CAES) is the other solution for large energy storage capacity. It can balance fluctuations in supply and demand of electricity. CAES is essential part of smart power grids. Linked with the flow structure and dynamic characteristic of electricity generation subsystem and its components, a simulation model is proposed. Thermo-dynamical performance on off-design conditions have been analyzed with constant air mass flux and constant gas combustion temperature. Some simulation diagrams of curve are plotted too. The contrast of varied operation mode thermal performance is made between CAES power plant and simple gas turbine power plant.
