Mechanics of robot inspector on electrical transmission lines conductors: performance analysis of dynamic vibration absorber

The aim of this paper is to create a mathematical model of the movement of electrical transmission lines inspection robot while moving on the line. In this model, the electrical line is considered as a stretched string while the robot considered as a moving load on the line. The obtained equation of motion has been solved by using the Lagrange equation. Even the motion of the inspection robot on the line is steady, but dangerous vibrations in the vertical plane of the motion have been observed. These types of oscillation may cause parametric oscillations in the perpendicular plane since the robot-inspector considered as moving load and pendulum. To achieve dynamical stability during the movement of inspection robot on the electrical line and avoid dangerous oscillation, dynamic vibration absorber has been designed. Then the performance of dynamic vibration absorber has been investigated

Structural synthesis for broken strands repair operation metamorphic mechanism of EHV transmission lines

Special operation requirements are needed for repositing broken strands of extra-high-voltage (EHV) power transmission lines before repairing. Metamorphic mechanism is applied to satisfy the requirements and a novel structural synthesis method is proposed, considering the forms and structures of constrained metamorphic joints. Metamorphic cyclogram and equivalent resistance gradient matrix of metamorphic joints are obtained by analyzing the repairing operation. Meanwhile, the source metamorphic mechanism with structure of non-constrained metamorphic joints is selected. Constrained form/structure matrix of metamorphic joints is built according to metamorphic cyclogram and equivalent resistance gradient matrix. The relation between constraint force changes of joints and form/structure of metamorphic joints is then obtained; and all the eight corresponding structures of constrained metamorphic mechanism are synthesized. One of the eight mechanisms is chosen as the broken strands reposition metamorphic mechanism, and its topological transformations of working configuration are analyzed to verify the feasibility and practicality of structural synthesis method proposed in this paper

The Operation of UAV Propulsion Motors in the Presence of High External Magnetic Fields

From MDPI via Jisc Publications RouterHistory: accepted 2021-06-01, pub-electronic 2021-06-09Publication status: PublishedFunder: Engineering and Physical Sciences Research Council; Grant(s): EP/P009743/1The operation and maintenance of converter stations (also known as valve halls) in high voltage DC (HVDC) grids is a key element in long-term, reliable and stable operation, especially in inherently adverse offshore environments. However, the nature of the electromagnetic field environment inside HVDC valve halls presents a challenge for the operation of traditional off-shelf inspection robots. In this paper, the impact of the external magnetic field on the operation of an inspection UAV’s propulsion motors is assessed. An experimental method is proposed to simulate the maximum magnetic field interference to off-shelf UAV motors, which can be used to identify their suitability for use in HVDC valve halls inspection robots. The paper’s experimental results compare the performance of direct torque control and field-oriented control algorithms for propulsion motors under the influence of external magnetic flux. Under the influence of a 177 mT external magnetic field, it was found that using direct torque control, the motor rotational velocity steady-state error was up to 55%. With field-oriented control, the steady-state error was 0%, however the peak-to-peak current draw increased by up to 567%

A Power Line Inspector Device

The goal of this project is to create a functional power line inspection device which could replace the old inspection method of using helicopters. This microchip based robotic device is able to ride along a conductor and send video feed, encoder readouts, and temperature measurements to the user. The user operating system consists of an LCD screen, two potentiometers for motor control, and a screen to display video feed. Achieved specifications include a battery lifetime of 1 hour and 45 minutes, distance measurements within 1 inch, and temperature accuracy within 2 °C. This thesis includes a brief discussion on previous methods and robots, theory of operation, design summaries, and a compilation of the final results

Diseño de hexacóptero autónomo para mantenimiento en líneas eléctricas

El mantenimiento predictivo en líneas eléctricas es un trabajo necesario pues este garantiza que los usuarios de energía eléctrica tengan un servicio de calidad. Este trabajo se realiza con cámaras termográficas o de efecto corona ya que estas detectan potenciales fallos en las líneas. Las líneas eléctricas recorren todo tipo de terrenos, incluso algunos no accesibles por tierra, por lo que este mantenimiento se lleva a cabo usando helicópteros y vehículos todo terreno, lo que lo hace costoso, lento e ineficiente considerando que las líneas eléctricas se tienden por miles de kilómetros. Actualmente, también se hace uso de vehículos aéreos no tripulados para llevar a cabo este mantenimiento; sin embargo su operario debe volarlo a la vez que reconoce las fallas, por lo que este método también puede resultar lento y a la vez riesgoso para el sistema, pues el operario lo puede llevar cerca de las líneas eléctricas y dañar sus circuitos debido al campo magnético de estas. En el presente trabajo se buscó hacer un mantenimiento predictivo basado en termografía en líneas de alta y media tensión más rápido, sencillo, seguro y menos costoso comparado con los métodos convencionales para las empresas mediante el uso de un hexacóptero autónomo que lo lleve a cabo. Para poder lograr lo propuesto se hizo uso de una cámara termográfica que detecta los posibles fallos en las líneas, además de una cámara de profundidad que le da autonomía al sistema ya que con esta se pueden seguir las líneas, evitar obstáculos, mantenerse a una distancia preestablecida del suelo, entre otras características. Este sistema puede realizar la inspección a 30km/h, no necesita de operarios que lo manejen, se mantiene a una distancia segura de las líneas y a largo plazo resulta ser menos costoso que transportarse en helicóptero o en vehículos todo terreno para realizar la inspección.Tesi

Design and Validation of a Mobile Robot for Power Line Inspection and Maintenance

International audienceThis paper presents the LineScout Technology, a mobile teleoperated robot for power line inspection and maintenance. Optimizing several geometric parameters achieved a compact design that was successfully tested over many line configurations and obstacle sequences. An overview of the technology is presented, including a description of the control strategy, followed by a section focusing on key aspects of the prototype thorough validation. Working on live lines, up to 735 kV and 1,000 A, means that the technology must be robust to electromagnetic interference. The third generation prototype, tested in laboratory and in field conditions, is now ready to undertake inspection pilot projects