Applied Mechanics and Materials Vols. 494-495

Abstract: This article discusses energy conservation for air conditioning systems in rail transit stations. At first, the paper analyzes the energy consumption condition in the air conditioning systems in rail transit stations. Then, it discusses application of appropriate control strategy for reducing energy consumption. In the end, the paper calculates effiency and amount of the energy saving based on the control strategy.

Abstract: The high-voltage transmission tower transmission lines is a major component and typically a high steel tower, is a tall, flexible structures. In this paper, the finite element method to establish a large-scale three-dimensional model of the transmission tower space, computational analysis of the transmission tower structure first six buckling modes and critical load, examined the order buckling mode characteristics. Research on the structural stability of large power transmission tower design has some theoretical significance and application value.

Abstract: Actual characteristics of Switched Reluctance Generator (SRG) are simply introduced. Control strategy of developed output voltage optimization and maximum power point tracking (MPPT) method are proposed and the applications are analyzed in detail. Simulation results show that the voltage optimization can be realized with developed regulation system on the basis of fuzzy logic scheme, while MPPT also can be perfectly performed by feedback information of SRG rotational speed as well as its change direction signal; finally excellent electrical energy quality can be sent out, and favorable conversion efficiency can be maintained during different working environments.

Abstract: At present, the situations of long period independent operation of each kind of distribution and consumption management system and lack of effective integration, it obstructed the inter-departmental coordination of business operations. According to IEC61968, the paper proposed a smart distribution and consumption integrated management system that integration of existing systems at the distribution and consumption side. The system can solve the problem of information islands. With the scope of the power system data acquisition continues to expand, in the future need mass data storage and analysis capabilities, it is insufficient of the existing storing and information-processing platform of the power system, the cloud storage based on Hadoop can solve the problem. The Experiments show that cloud storage based on Hadoop clusters has characteristics of high throughput rates and high transmission rate, which can meet the mass data storage access requirements of the smart distribution and consumption integrated management system.

Abstract: The traditional power system shows regional power load density using the dot density way, while it performs some shortages in showing regional density visualization during zooming in webgis process. By improving density point generation algorithm and using heatmap technology, this paper designing and implementing the visualization method of regional electricity load density which is based on heatmap technology in WebGIS (web geographic information system). Also, this paper shows that the image rendering performance and map zoom visual performance are improved when using heatmap method performs regional power load density through experiments.

Abstract: In the context of south china electricity market, the concept of contract transfer and replacement deal is set forth in advance which is specialized in electricity treatment. Then, the feasibility of conducting an inter-provincial contract transfer and replacement is analyzed according to the aspects of physical characteristics, economics and policies within the china southern power grid. In addition, the advantage and disadvantage are also presented in terms of bilateral negotiation and centralized biding transaction modes. After that, the pricing mechanism and transaction mode are deliberately designed pertaining to three different situations including a party power shortage and a party "abandon water", a party power supply shortage and a party power surplus and a party power surplus and a party "abandon water". Finally, the realistic feasibility of the proposed schemes is verified through an employed numerical example.

Abstract: . Considering of the highly nonlinear, time-variable and complex dynamics and the easy variance of hydrogenerator set systems structure and parameters, a nonlinear dynamical model is presented, which can be analyzed by the bifurcation theory of nonlinear differential equations and simulated in computer. By using the genetic algorithm, the PID parameters of hydrogenerator set intelligent system are optimized and the control performances are improved. The algebra criterion about the existence of bifurcation is employed to study the bifurcation behavior of the nonlinear model which takes the PID parameters as the bifurcation ones. The simulations show that a supercritical bifurcation is likely to exist in hydrogenerator set system and the bifurcation will occur for the higher values of PID parameters. Theory and simulation results of this paper can be considered as good suggest for intelligent PID control system of hydrogenerator set system.

Abstract: Traditional control methods are usually difficult to achieve a good compromise between nominal performance and robust performance, in order to improve the flexibility and robustness of the PV power grid-connection system without affecting its nominal performance, aiming at the effect on flexible PV power grid-connection by component parameter perturbation, a μ-synthesis robust control method of flexible grid-connection of photovoltaic power based on model matching is proposed. Model matching problem including the actual controlled objects like inverters, is transformed into a generalized system with uncertainty block being abstracted, thus further is attributed to a structured uncertainty problem, which can be solved by DK iteration. The μ-analysis and simulation results show that the designed μ-synthesis controller, makes the robust performance of the closed-loop system satisfied, and advantages are especially more obvious in the case of system component parameter perturbation.

Abstract: This article summarizes the methods of Maximum Power Point Tracking (MPPT),including the CVT, P&O, INC and intelligent control, and merits and demerits are narrated in detail. Their recent research results are analyzed, finally the prospect of the development trend in MPPT photovoltaic power generation system is discussed.

Abstract: The classic multi-objective optimization method of sub goals multiplication and division theory is applied to solve optimal load distribution problem in thermal power plants. A multi-objective optimization model is built which comprehensively reflects the economy, environmental protection and speediness. The proposed model effectively avoids the target normalization and weights determination existing in the process of changing the multi-objective optimization problem into a single objective optimization problem. Since genetic algorithm (GA) has the drawback of falling into local optimum, adaptive immune vaccines algorithm (AIVA) is applied to optimize the constructed model and the results are compared with that optimized by genetic algorithm. Simulation shows this method can complete multi-objective optimal load distribution quickly and efficiently.