Advanced Materials Research Vols. 383-390

Abstract: In order to enhance the sun tracking accuracy of photovoltaic power generation system and reduce the manufacturing cost of sun tracking devices, a new sun tracking method and corresponding tracking device was presented in this paper. The new method is to get two driving rotational angle parameters by conversing solar azimuth parameter and solar altitude parameter. According to the new parameters, the solar cell panel is driven to rotate as the universal-joint movement in order to track the sun. The new tracking device consists of solar direction monitoring module, parameter calculation module, driving device, direction error detection module, and feedback control module. It can acquire solar direction parameter to complete new angle parameters conversion and it can amend real-time interaction frequency and stride according to the direction error of solar cell panel. The new tracking device has features of high tracking accuracy, small tracking time intervals, simple structures and low manufacturing cost.

Abstract: Offshore wind farm is developed in the ascendant currently. The reliable operation, power loss, investment cost and performance of wind farms were effect by the integration solutions of electrical interconnection system directly. Several new integration configurations based on VSC-HVDC were comparative analyzed. For the new HVDC topology applied the wind farm internal DC bus, the Variable Speed DC (VSDC) system that is suitable for those topologies was proposed. The structure of VSDC was discussed and maximum wind power tracking was simulated on the minimal system. It is clear that new integration configurations based on VSC-HVDC has good prospects.

Abstract: A supervisory control and data acquisition system is designed for wind farms, including the local controller and remote monitoring terminal. The data of the sensors collected by the lower-computer is transmitted to the host computer monitor terminal through the GPRS wireless network after preliminary treatment. In the host computer, the data is processed and displayed by the virtual instrument. The remote monitoring terminal can also send commands to control the actuators in the wind farm. Wavelet de-noising principle is used to process the data collected, improving the reliability and stability of the system.

Abstract: This paper analyzes the factors on dynamic economic dispatch including wind farms. Environmental economic dispatch model including wind farms is proposed. Considering the thermal power generation cost, thermal power polluting emissions and low cost of wind power generation, the objective function is to minimize the total cost in system. Environmental economic dispatch including wind farm is studied with chaotic ant colony optimization algorithm which has advantage of strength searching capability and fast optimizing. Meanwhile, the application of the relative entropy balance theory is on evaluation and selection to the decision results. The simulation results show the model and algorithm are correct and effective.

Abstract: With the development of new energy industry, the technicians in the area of solar-wind complementary grid-connected power generation are urgently needed. For this reason, the monitoring system of 10kW solar-wind complementary grid-connected power generation was designed. Hardware system includes field device, communication network and monitoring host. Software design includes operation monitoring, application analysis, video surveillance, information issuing. It realizes functions of supervise and control, equipment events and alarm, report forms and print, energy management and forecasting, remote monitoring and so on. This research can be used to demonstrate experimental teaching in high shool and train power enterprise technicians.

Abstract: Keeping wind energy conversion system (WECS) running on maximum power point (MPP) can make full use of wind energy. In this paper, authors put forward a novel hybrid maximum power point tracking (MPPT) algorithm which combines three points comparing (TPC) method with power-signal feedback (PSF) method. WECS based on doubly-salient electro-magnetic generator (DSEG) is used to validate the effectiveness of proposed algorithm. The whole WECS is simulated in Matlab/SimuLink, simulation results obtained confirm that the proposed algorithm is more fast and efficient than TPC method.

Abstract: Noting that in traditional study, the dynamic response of the tower structure under wind load is usually analyzed by explicitly applying equivalent force on nodes of the tower’s finite element model which may oversimplify the flow-structure interaction interface, this paper presents a fully coupled finite element study of the dynamic response of monopole steel tower. Coupled finite element analysis is used to model the interaction between the steel tower and the wind flow. The steel tower is composed of tubes and is modeled using solid element, while the wind flow is governed by Navier-Stokes equations for incompressive flow. Parameters such as the viscosity of the flow and boundary conditions (wind velocity at different height) are measured from experiments. At each time step of the calculation, winslow moving mesh is used to rezone the computational grid to ensure the accuracy. Simulation is given for studying the deformation pattern of the tower structure.

Abstract: Evaluation on energy characteristics of a wind-excited transmission tower-line system is actively carried out in this study. The analytical method of a transmission tower-line system is established. The evaluation criteria of energy responses is developed and applied to the wind response analysis of a transmission tower. A real transmission tower-line system constructed in China is taken as an example to examine the feasibility and reliability of the proposed approach. The observations from numerical investigation indicate that the proposed energy evaluation criteria can be effectively utilized in the examination on structural dynamic performance.

Abstract: As the information collection device of the current domestic down-hole gathers less information and with low precision, the down-hole monitoring system with multi-parameter is designed in this paper. The system can be used on electric submersible pump to achieve two-way pressure, two-way temperature, leakage current, and vibration signals in real-time acquisition. Filtering the collected data, and using curve fitting algorithm on the pressure sensor for temperature compensation to ensure the accuracy of the data. Test results show that the system can withstand the harsh down-hole environments encountered in an oil well. Plus, the gathered data has high precision and timeliness. Accordingly, it reaches the expected target.

Abstract: Transmission line systems are vulnerable to winds and storms, particularly in cold climate regions where atmospheric ice accretes on network equipment. This paper describes a method for analyzing wind-induced vibrations of ice coating transmission towers coupled with power lines. An ice coating model of transmission line systems is introduced. Wind loads on ice coating transmission line systems are also presented. The time histories of wind speed acting on transmission line systems are simulated with the harmony superposition method. Finally, the responses of ice coating transmission line systems under different thickness of ice and different wind velocity are discussed. The results show that the displacement and unbalanced tension increase rapidly with the thickness of ice and wind velocity increasing. The value of the unbalanced tension increases significantly when the ice coating on conductors is nonuniform.