The Experts below are selected from a list of 83868 Experts worldwide ranked by ideXlab platform

Zhang Guocheng - One of the best experts on this subject based on the ideXlab platform.

  • single phase magnetic operating mechanism vacuum circuit breaker and intelligent vacuum circuit breaker system
    2014
    Co-Authors: Zhang Zhaoxian, Zhang Guocheng
    Abstract:

    The utility model relates to a single-phase magnetic operating mechanism vacuum circuit breaker, and an intelligent vacuum circuit breaker system comprising the circuit breaker and a driving controller. A magnetic operating mechanism of the circuit breaker comprises a cylindrical magnetic conduction ring, upper and lower magnet yokes connected to the upper and lower ends of the magnetic conduction ring, a magnetic circuit assembly, a movable magnetic core, a magnetic excitation coil, an opening spring and a contact pressure spring. The magnetic excitation coil is arranged in the magnetic conduction ring. At least the upper part of the movable magnetic core is disposed in a columnar space defined by an inner hole of the magnetic excitation coil. An output rod passes through the movable magnetic core up and down. The upper end of the output rod is connected with a movable contact. The opening spring and the contact pressure spring coaxially sleeve the output rod, the lower ends of the opening spring and the contact pressure spring abut against the movable magnetic core, the upper end of the opening spring abuts against the upper magnet yoke, and the upper end of the contact pressure spring is relatively fixed to the output rod. The single-phase magnetic operating mechanism vacuum circuit breaker and the intelligent vacuum circuit breaker system of the utility model are simple in structure and low in cost, no closing bounce occurs, magnetism can be long kept, phase Selection Operation and online self monitoring can be realized, and the use requirements of a smart grid can be satisfied.

  • vacuum circuit breaker with single phase magnetic Operation mechanism and intelligent vacuum circuit breaker system
    2014
    Co-Authors: Zhang Zhaoxian, Zhang Guocheng
    Abstract:

    The invention relates to a vacuum circuit breaker with a single-phase magnetic Operation mechanism and an intelligent vacuum circuit breaker system comprising the circuit breaker and a driving controller. The magnetic Operation mechanism of the circuit breaker comprises a tubular magnetic ring, an upper magnet yoke, a lower magnet yoke, a magnet loop assembly, a movable magnetic core, an exciting coil, a disconnecting spring and a contact pressure spring, wherein the upper magnet yoke and the lower magnet yoke are connected to the upper end and the lower end of the magnetic ring, the exciting coil is arranged in the magnetic ring, at least the upper portion of the magnetic core is located in a columnar space defined by an inner hole of the exciting coil, an output rod is arranged in the movable magnetic core in a vertical-penetrating mode and is coaxially sleeved with the disconnecting spring and the contact pressure spring, the upper end of the output rod is connected with a moving contact, the lower end of the disconnecting spring and the lower end of the contact pressure spring abut against the movable magnetic core, the upper end of the disconnecting spring abuts against the upper magnet yoke, and the upper end of the contact pressure spring and the output rod are relatively fixed. The vacuum circuit breaker is simple in structure, low in material and manufacturing cost, free of connecting bouncing and capable of keeping magnetism for a long time, achieving phase Selection Operation and on-line self-monitoring and meeting using requirements for intelligent power grids.

Manjaree Pandit - One of the best experts on this subject based on the ideXlab platform.

  • multi period wind integrated optimal dispatch using series pso de with time varying gaussian membership function based fuzzy Selection
    International Journal of Electrical Power & Energy Systems, 2015
    Co-Authors: Manjaree Pandit, Vishal Chaudhary, Hari Mohan Dubey, B K Panigrahi
    Abstract:

    Abstract Wind power has emerged as the most promising option for providing sustainable eco-friendly power supply to the modern world. Due to its unpredictable nature, integration of wind power into the conventional power grid is a very challenging task having dynamic characteristics. Due to the inherent uncertainty associated with wind availability, additional spinning reserve needs to be scheduled in order to maintain security and supply reliability. Multi-period multi-objective optimal dispatch (MPMOOD) is presented for wind integrated power system with reserve constraints. The complex relationship between wind power availability, spinning reserve allocation and their impact on economic/environmental cost are analysed using an elaborate model. A new multi-objective Series PSO-DE (SPSO-DE) hybrid algorithm is proposed where the two paradigms, differential evolution (DE) and particle swarm optimization (PSO) share domain information and maintain a synergistic coOperation to overcome their individual weaknesses. For multi-objective (MO) problems, the Selection Operation in SPSO-DE is replaced by a 5-class time-varying fuzzy Selection mechanism (TVFSM) to avoid saturation and to increase Pareto diversity. To promote convergence towards the central part of the Pareto front and to quickly isolate the boundary solutions, Guassian membership function is employed. Elitism is applied to preserve good solutions and momentum Operation is used to stop premature convergence. The proposed method expedites the search for the best solution, i.e. the solution which satisfies all the objectives of the MO problems. To test the performance and computational efficiency, the proposed method is applied on two standard test power systems.

  • environmental economic dispatch in multi area power system employing improved differential evolution with fuzzy Selection
    Applied Soft Computing, 2015
    Co-Authors: Manjaree Pandit, Laxmi Srivastava, Manisha Sharma
    Abstract:

    A multi-objective differential evolution technique with fuzzy Selection (DEFS) is proposed.A momentum Operation is also included to prevent stagnation and to create Pareto diversity.DEFS is applied to multi-area nonconvex environmental economic dispatch (MANCEED).Many complex equality and inequality constraints are considered with multi-area constraints.The DEFS performance is validated and compared with results from previous literature. In a deregulated multi-area electrical power system the objective is to determine the most economical generation dispatch strategy that could satisfy the area load demands, the tie-line limits and other operating constraints. Usually, economic dispatch (ED) deals only with the cost minimization, but minimization of emission content has also become an equally important concern due to the mandatory requirement of pollution reduction for environmental protection. Environmental economic dispatch (EED) is a complex multi-objective optimization (MOO) problem with conflicting goals. Normally a fuzzy ranking is employed to rank the large number of Pareto solutions obtained after solving a MOO problem. But in this paper the preference of the decision maker (DM) is used to guide the search and to select the population for the next generation. An improved differential evolution (DE) method is proposed where the Selection Operation is modified to reduce the complexity of multi-attribute decision making with the help of a fuzzy framework. Solutions are assigned a fuzzy rank on the basis of their level of satisfaction for different objectives before the population Selection and then the fuzzy rank is used to select and pass on better solutions to the next generation. A well distributed Pareto-front is obtained which presents a large number of alternate trade-off solutions for the power system operator. A momentum Operation is also included to prevent stagnation and to create Pareto diversity. Studies are carried out on three test cases and results obtained are found to be better than some previous literature.

Manisha Sharma - One of the best experts on this subject based on the ideXlab platform.

  • environmental economic dispatch in multi area power system employing improved differential evolution with fuzzy Selection
    Applied Soft Computing, 2015
    Co-Authors: Manjaree Pandit, Laxmi Srivastava, Manisha Sharma
    Abstract:

    A multi-objective differential evolution technique with fuzzy Selection (DEFS) is proposed.A momentum Operation is also included to prevent stagnation and to create Pareto diversity.DEFS is applied to multi-area nonconvex environmental economic dispatch (MANCEED).Many complex equality and inequality constraints are considered with multi-area constraints.The DEFS performance is validated and compared with results from previous literature. In a deregulated multi-area electrical power system the objective is to determine the most economical generation dispatch strategy that could satisfy the area load demands, the tie-line limits and other operating constraints. Usually, economic dispatch (ED) deals only with the cost minimization, but minimization of emission content has also become an equally important concern due to the mandatory requirement of pollution reduction for environmental protection. Environmental economic dispatch (EED) is a complex multi-objective optimization (MOO) problem with conflicting goals. Normally a fuzzy ranking is employed to rank the large number of Pareto solutions obtained after solving a MOO problem. But in this paper the preference of the decision maker (DM) is used to guide the search and to select the population for the next generation. An improved differential evolution (DE) method is proposed where the Selection Operation is modified to reduce the complexity of multi-attribute decision making with the help of a fuzzy framework. Solutions are assigned a fuzzy rank on the basis of their level of satisfaction for different objectives before the population Selection and then the fuzzy rank is used to select and pass on better solutions to the next generation. A well distributed Pareto-front is obtained which presents a large number of alternate trade-off solutions for the power system operator. A momentum Operation is also included to prevent stagnation and to create Pareto diversity. Studies are carried out on three test cases and results obtained are found to be better than some previous literature.

Zhang Zhaoxian - One of the best experts on this subject based on the ideXlab platform.

  • single phase magnetic operating mechanism vacuum circuit breaker and intelligent vacuum circuit breaker system
    2014
    Co-Authors: Zhang Zhaoxian, Zhang Guocheng
    Abstract:

    The utility model relates to a single-phase magnetic operating mechanism vacuum circuit breaker, and an intelligent vacuum circuit breaker system comprising the circuit breaker and a driving controller. A magnetic operating mechanism of the circuit breaker comprises a cylindrical magnetic conduction ring, upper and lower magnet yokes connected to the upper and lower ends of the magnetic conduction ring, a magnetic circuit assembly, a movable magnetic core, a magnetic excitation coil, an opening spring and a contact pressure spring. The magnetic excitation coil is arranged in the magnetic conduction ring. At least the upper part of the movable magnetic core is disposed in a columnar space defined by an inner hole of the magnetic excitation coil. An output rod passes through the movable magnetic core up and down. The upper end of the output rod is connected with a movable contact. The opening spring and the contact pressure spring coaxially sleeve the output rod, the lower ends of the opening spring and the contact pressure spring abut against the movable magnetic core, the upper end of the opening spring abuts against the upper magnet yoke, and the upper end of the contact pressure spring is relatively fixed to the output rod. The single-phase magnetic operating mechanism vacuum circuit breaker and the intelligent vacuum circuit breaker system of the utility model are simple in structure and low in cost, no closing bounce occurs, magnetism can be long kept, phase Selection Operation and online self monitoring can be realized, and the use requirements of a smart grid can be satisfied.

  • vacuum circuit breaker with single phase magnetic Operation mechanism and intelligent vacuum circuit breaker system
    2014
    Co-Authors: Zhang Zhaoxian, Zhang Guocheng
    Abstract:

    The invention relates to a vacuum circuit breaker with a single-phase magnetic Operation mechanism and an intelligent vacuum circuit breaker system comprising the circuit breaker and a driving controller. The magnetic Operation mechanism of the circuit breaker comprises a tubular magnetic ring, an upper magnet yoke, a lower magnet yoke, a magnet loop assembly, a movable magnetic core, an exciting coil, a disconnecting spring and a contact pressure spring, wherein the upper magnet yoke and the lower magnet yoke are connected to the upper end and the lower end of the magnetic ring, the exciting coil is arranged in the magnetic ring, at least the upper portion of the magnetic core is located in a columnar space defined by an inner hole of the exciting coil, an output rod is arranged in the movable magnetic core in a vertical-penetrating mode and is coaxially sleeved with the disconnecting spring and the contact pressure spring, the upper end of the output rod is connected with a moving contact, the lower end of the disconnecting spring and the lower end of the contact pressure spring abut against the movable magnetic core, the upper end of the disconnecting spring abuts against the upper magnet yoke, and the upper end of the contact pressure spring and the output rod are relatively fixed. The vacuum circuit breaker is simple in structure, low in material and manufacturing cost, free of connecting bouncing and capable of keeping magnetism for a long time, achieving phase Selection Operation and on-line self-monitoring and meeting using requirements for intelligent power grids.

Yuling Song - One of the best experts on this subject based on the ideXlab platform.

  • prediction of cooling efficiency of forced air precooling systems based on optimized differential evolution and improved bp neural network
    Applied Soft Computing, 2019
    Co-Authors: Jiawei Han, Huaji Zhu, Yuling Song
    Abstract:

    Abstract This paper proposes an approach to predict the efficiency of forced-air cooling of fresh apples that combines the optimized differential evolution (DE) algorithm and the back-propagation (BP) neural network algorithm. First, to balance population diversity and fast convergence, the individual mutation Operation of the basic DE algorithm was optimized by dividing the entire population into two equal parts according to the fitness value of individuals, and DE-best-1 and DE-current-to-rand-1 are used as individual mutation Operations for the superior- and inferior-part individuals, respectively. Moreover, the Selection Operation of basic DE was also changed by using a crowding scheme, which helps maintain population diversity and discover more regions containing the global optima. Second, an optimized DE-BP neural network model was established by using the optimized DE to determine the initial weights and thresholds of the BP neural network to avoid being trapped in local minima, following which the effect of input parameters on the network output was subjected to a comprehensive sensitivity analysis based on the trained neural network. The results show that the optimized DE-BP model accurately predicts the efficiency with which apples are cooled. Furthermore, the airflow velocity and total opening area have a significant negative correlation with the average apple temperature and a positive correlation with the cooling rate of the apples. Finally, the most important factor influencing the cooling efficiency of the pre-cooling system is the total opening area of the ventilated packaging.