Kuan Jun Zhu

Numerical and Experimental Simulation on Aerodynamic Character of Crescent-Shaped Iced Conductor

The dynamics force of iced-conductor is the driving force of galloping, its variation is depended on the aerodynamic character of iced conductor. The aerodynamic character of iced conductor is the key factor of galloping of iced-conductor, but the result of theoretically analysis and numerical simulation isn’t suited for the requirement of transmission line project. In the paper, basing on the theoretically analysis and numerical simulation, the simulation tests in wind tunnel of crescent-shaped iced conductor is stetted up and put into practice, and then the systemic study is carried into execution. The result of research is indicated that there is a better coherence between the numerical simulation and experiment test, and the result of numerical simulation is the beneficial supplement to the experiment test. The result can not only provide the original date for the galloping analysis, but also validate the affectivity of numerical simulation, support the research of mechanism and control of galloping.

Research and Application on Nonlinear Control Algorithms Based on Viscous Dampers

One challenge in the use of semi-active technology is in developing nonlinear control algorithms that are appropriate for implementation in full-scale structures. Based on the basic characteristics of magnetorheological (MR) damper, the structural control algorithms are introduced. The nonlinear control algorithms are systematically reviewed from the aspects including clipped optimal control, LQR control, and Lyapunov stability control. Finally, the existed problem in application and the future developing in research on the structural control algorithms are summarized respectively.

Experimental Simulation on Aerodynamic Character of D-Shaped Iced Conductor

The dynamics force of iced-conductor is the driving force of galloping; its variation is depended on the aerodynamic character of iced conductor. The aerodynamic character of iced conductor is the key factor of galloping of iced-conductor, but the result of theoretically analysis and numerical simulation isn’t suited for the requirement of transmission line project. In the paper, basing on the theoretically analysis and numerical simulation, the simulation tests in wind tunnel of D-shaped iced conductor is stetted up and put into practice under different wind speed and iced thickness, and then the systemic study is carried into execution. The result of research is indicated that there is a better coherence between the numerical simulation and experiment test, and the variation rules of parameters is obvious with the different iced thickness, the result of numerical simulation is the beneficial supplement to the experiment test. The result can not only provide the original date for the galloping analysis, but also validate the affectivity of numerical simulation, support the research of mechanism and control of galloping.

Power Characteristic and Damper Effectiveness Evaluation of Vibration Damper for 1250mm2 Conductor

Power characteristic and damper effectiveness of the vibration damper for 1250mm2 Conductor is analysed by laboratory test. Resonance frequency, power dissipation and protectable span of the vibration damper are given in the test results, which indicates that power characteristic of the vibration damper meets the requirements of the industry standard and can provide a reference for anti-vibration design of 1250mm2 conductor, and the protectable span of the damper is 141m.

Analysis on Galloping Responses of Transmission Tower-Line System

Nonlinear finite element model of a transmission tower-line system was set up and galloping of iced bundle conductors in the system was numerically simulated by means of ANSYS software. Based on galloping trajectories, vibration frequency, galloping order, conductor tension; unbalanced tension characteristics of iced conductors, it was shown that values of the conductor amplitudes by the tower-line system model are increased by 20% compared to the conductor model. The values of the strain tower unbalanced tensions by the tower-line system model are decreased by 20% and the values of the suspension tower unbalanced tensions by the tower-line system model are decreased by 62.5% compared to the conductor model conductor-insulator mode1. The galloping order is different for different span, due to the impact of the order of galloping. The amplitude of the vertical galloping is increasing while the increasing span, but it is not linear increase.

The Feasibility Research on the New Material Used in Electrical Fittings

Based on the requirements of The Twelfth Five Years development planning of State Grid and the development of electrical fitting, State Grid will enlarge the change of rural power network and power distribution market, which will make the coverage of rural power network and power distribution to be larger so that reducing the loss of the power transmission line will become an important task research. To reduce or replace the high energy consumption steel fittings and the high price aluminum fittings, this article make feasibility analyses for a new material used in electrical fittings to protect the environment and economy energy source, by analyzing the performance and test property of the new material.

Application Study of Viscoelastic Damping Material for the Anti-Galloping of Overhead Transmission Lines

Based on the galloping mechanism of transmission line, it is determined to use viscoelastic damping material and energy effects of TMD to suppress galloping. The dynamic mechanical properties of viscoelastic damping material is studied, with the operating environment of the transmission lines, high-and-low-temperature physics experiment is carried out, while the experimental study on mechanical properties is carried out with the developed viscoelastic damping elements. It is showed that the viscoelastic material meets the anti-galloping device performance requirements for materials, it has a good energy consumption effect, suitable for application to anti-galloping of transmission lines.

Research on Numerical Simulation of Quad Bundle Conductor on Galloping

The models of the multi-bundled conductors are constructed by finite element method in this paper. The numerical results are given by using the 4th order Runge-Kutta method considering aerodynamic parameter of sub-conductor. The simulation results are obtained on galloping of quad bundle conductors with the different span. Thus some effective numerical results of quad twin bundle conductor can provide a useful reference for anti-galloping design.

Research on the Anti-Vibration Technology of Large Cross-Section Conductor

The conductor is an important part of the process of power transmission. Keep conductor to be normal operation is an important link of power transmission. In practice, Due to the influence of many weather environments, such as wind, temperature, rain and snow, the conductor often appear ice disaster, dance and other disasters; therefore, the anti-vibration technology of conductor is an urgent need to develop. This paper masters the performance of damper by carrying out a great deal of performance test analysis, such as self-damping, the power of damper, anti-vibration effect. At the same time, this paper understands the effect of spacer arrangement on the sub span oscillation, through the finite element analysis and lingo program of nonlinear programming, laying the foundation for studying anti-vibration technology for large cross-section conductor.

Research and Application of Vibration Control for Coupled Structures System

Over the past three decades, coupled structures vibration research has steadily gained momentum from proposed research concepts to actual implementation. Numerous passive and active control strategies have been considered for low- to high-rise buildings. This paper contains a literature review of coupled structures control, and reviewed from the aspects including neural control method, laboratory test, and engineering application. The existing problem and the future developing in application are also summarized respectively.