Advanced Materials Research Vols. 694-697

Abstract: The personal air conditioning system is used in the battery electric vehicle instead of the traditional one and the experiment validated that this system can make passengers feel comfort after four minutes. All the system can only consume electric power 338.8 W, which is less than the traditional air conditioning of cabin. A simplified 3-D N box vehicle cabin model was created to simulate the thermal distribution under this system by using the CFD analysis and the results of calculation have good agreement with the experiment recording.

Abstract: This paper establishes the finite element model of XK2535 gantry machining center ram structure, and considers the influence of bearing to the slippery pillow in the axial direction to analyzes the rams temperature field and thermal deformation based on ABAQUS. Finally using SINUMERIK 840D is to compensating thermal error of the ram.

Abstract: As the thermal deformation significantly impacts the accuracy of precision positioning stage, it is necessary to realize the thermal error. The thermal deformation of the positioning stage is simulated by the finite element analysis. The relationship between the temperature variation and thermal error is fitted third-order polynomial function whose parameters are determined by genetic algorithm neural network (GANN). The operators of the GANN are optimized through a parametric study. The results show that the model can describe the relationship between the temperature and thermal deformation well.

Abstract: The article presents the analysis of thermal flows into reactor walls within the semi-operational pyrolytic system. There were hydrodynamic and thermodynamic similarity theories and heat transfer by radiation laws used for the solution of this issue. The entry data for the heat transfer analysis were gained by conducted experiments. The correctness of the resulting values has been verified by measurements. The required reactor parameters, for the required heat intake, have been derived from the analytical results at the end of this article.

Abstract: The cold-end system of steam turbine is an important auxiliary system in thermal power plant, its operating mode has a direct impact on the output of the unit and auxiliary power. This paper uses an optimization analysis method to calculate the cold-end system of a 1000MW ultra-supercritical(USC) unit, and establishes a cold-end optimization system by using VB6.0 for a domestic ultra-supercritical unit, which provides an online guide for the operator by calculating the condenser. The results show that this system can provide some guidance for unit operation.

Abstract: In this paper, based on the choice of voltage level 500kV for large transformer differential protection of maloperation accident actually as an example, discusses how to improve the reliability and the transformer differential protection with the relationship between pressure test. Analysis found that in order to avoid the excitation transient exciting current transformer differential protection sparked the misoperation, on-site technical personnel in the differential protection setting calculation process, make use of data in conformity with the relevant parameters, rules and standards, familiar with differential protection, also need to understand the characteristics of transformer excitation transient exciting current high-voltage tests, the influence of characteristic more should fully exert the modern PC wave record device, instrument function can improve the actual effect of transformer differential protection. This factory for transformer differential protection for setting, protection greatly improves the reliability. This experience is worth popularizing.

Abstract: In view of the massive transmission lines suffered disaster of ice coating at the beginning of 2008 in south China. In this paper, several typical schemes for the prevention and treatment of ice coating occurred in power networks home and abroad are analyzed. Common melting ice methods can be divided into three kinds: thermal ice-melting, mechanical de-icing and new de-icing. This paper describes a 500 kV transmission line and analyses each of these measures briefly. At the same time, the advantages and disadvantages of various measures and their applications were summarized. At last, the development trend and the research direction were pointed out．

Abstract: Some simulation and experimental researches on magnetic-valve controlled reactor (MCR) have been done in this paper. Firstly, the equivalent circuit of MCR is derived according to the operational principle. Secondly, based on MATLAB/Simulink, the simulation model is established, in addition, the simulation researches are carried out. Thirdly, a MCR, with rated voltage 220V and rated capacity 600VA, is designed and tested. Comparing the experimental results with simulation results prove the validity of simulation model.

Abstract: This paper proposes an optimal mean power function index based on the weighted multi-index method for the electrical network containing wind farm. It combines the index of Jacobi matrix mutual condition number with the index of sensitivity inverse matrix elements the power and are obtained by the self program. The EPRI-36 node test system and a regional power grid containing large wind farms are selected to test the validity of the proposed index. The results show that this index has a shorter calculation time and accurate prediction compared to the traditional voltage stability indexes. It is available to predict the voltage stability of the electrical network containing wind farm under light load and provide a new theoretical method to analyze the voltage stability.

Abstract: Clark’s transformation can be used to conduct a modal analysis of perfectly balanced three-phase lines. For un-transposed transmission lines, the parameter matrices of line such as impedance matrix and admittance matrix are no longer symmetrical matrices, so Clark’s transformation can’t be used directly in modal analysis. Nevertheless, it still plays an important role in determining the exact phase-mode transformation matrix. This paper showed how this can be done by a series of matrix transformation starting with Clark’s transformation and then used the corrected Clark’s transformation in modal analysis.