Advanced Materials Research Vols. 960-961

Abstract: This paper establishes the COGAG system simulation model in the environment of SIMULINK and ADAMS with the method of coupled simulation based on multiple simulation platforms; simulates and analyses the COGAG engaging process with the simulation model. Dynamic change rules of some key parameters such as speed, moment, power are obtained and analysed detailed, which plays an important role in development and application of COGAG device.

Abstract: A study was carried out on the influence of different back pressures on internal flow of diesel injector nozzles. For this study, a flow visualization experimental system equipped with a pressurized chamber was setup. Experimental results show that, with the injection pressure remain constant and increase back pressure leading to the cavitation area diminished gradually and even disappeared. With a same pressure difference, higher back pressure test condition promoted the outlet mean velocity and inhibited the occurrence of cavitation inception, which demanded a larger pressure difference to make it happen. Moreover, it also resulted in a relatively large flow losses to the single phase flow compared to the cavitating flow.

Abstract: Based on the structure, the hydraulic scissor lift platform can be divided into different component modules. The maximum lifting force is calculated in accordance with its structure features, and then the safty is analyzed.

Abstract: Wartsila RT-flex 60C diesel engine is selected as the object to research pressure control of fuel common rail system, building the system simulation model, and analyzing main factors influencing rail pressure in the system. it was concluded that they were diesel engine speed, load. In the process of MATLAB/Simulink simulation, the rail pressure control logic was designed by adopting maps with the two factors as independent variables to get theory feedforward quantity of fuel rack, feedback quantity of fuel rack is obtained by fuzzy PID control. The simulation experiments show that the improved control method reduces the rail pressure fluctuation, at the same time the overshoot volume of dynamic rail pressure control is greatly reduced, response velocity quickened. The control method has been used in a Marine simulator.

Abstract: The impact of distributed generation (DG) on distribution power losses is closely related to DG technologies and load distribution. DG units are modeled as PQ, PQ(V) and PV nodes in power flow calculation. A revised back/forward power flow method is employed to calculate distribution power flow with various types of DG units. Power losses are computed when different types of DG units are connected to heavy load, general load and light load area apart. Simulation on IEEE 33-bus distribution network shows that connecting DG to heavy load area helps to maximize the loss reduction. And the installation of DG consuming reactive power will increase network losses unless reactive power compensation device is installed accordingly.

Abstract: This paper constructs the evaluation index system of electricity competitiveness in terminal energy consumption, evaluates the electricity competitiveness in Ningxia region from 2005 to 2011 using principal component analysis (PCA), and compares the evaluation results of PCA, the linear weighted method, the comprehensive index method and TOPSIS-grey correlation method. The compatibility degree and difference degree of each method are analyzed and calculated to verify the applicability of the PCA. The results show that PCA is the most scientific and appropriate evaluation method.

Abstract: To determine the pumped storage capacity is a comprehensive decision-making problem. This paper presents the entropy weight method to decide the weight in fuzzy comprehensive evaluation. Example analysis shows the effectiveness of the proposed methods.

Abstract: This paper sets the thermal power plant security management system as the research object. First of all, with the application of the Interpretative Structural Modeling (ISM), we establish a multi-level hierarchical structure model on analysis of the influencing factors of thermal power plant security management. Furthermore, based on the structure model, we use the Analytic Hierarchy Process (AHP) to determine weights of all the influencing factors, in order to identify the main factors. Finally, according to the identified main factors, we provide several suggestions for security management of thermal power plant.

Abstract: The thesis describes the loss model of distribution network and gives the transformer loss model and line loss model, Then it proposes some loss reduction measures at the stage of planning and design as well as operation and maintenance. Finally, according to the main problems about the loss reduction measures in China, it puts forward some countermeasures to reduce line loss . Distribution network as part of the end for power configuration which is directly connected with the users of demand side. The loss of distribution network has been high because of feeder radius, complex voltage grade and a large number of devices on the network. The line loss of distribution network represents a major component of the line loss in the whole power system, the line loss of 10kv and below distribution network accounts for about 78% in it according to statistical analysis[1-2]. So, under the current energy shortage situation, there is a great economic and social significance to adopt the reasonable measures to save energy and decrease loss in distribution network.

Abstract: Through the analysis of some parameters of Chinese power plants operation in recent years, forecasting that at a certain period in the future, total installed capacity of 6000 kw or more units will have the growth rate of 7% - 8%.China's power supply coal consumption rate will continue to become lower by 3-5g/kwh every year.