Study on Response Spectrum of Seismic Design of Ultra High Voltage Converter Valves in Bedrock Site

It is difficult to evaluate seismic performance of ultra-high voltage (UHV) converter valves reasonably because the response spectrum period used in seismic design of electrical equipment fails to cover the structural period of UHV converter valves at present. Bedrock response spectrum is the basis of seismic design response spectrum. 471 records of long period strong earthquakes in bedrock were analysed. The amplification power spectra and average spectra of all records were calculated. The seismic hazard analysis of 17 typical UHV converter stations was carried out, and the bedrock response spectra with exceedance probability of 10% and 2% in 50 years were proposed. The structural forms of the existing main response spectrum descending segments were compared and analysed. The corresponding response spectra of the long period strong earthquake records and the bedrock response spectra of the UHV converter station were fitted. The bedrock response spectrum of the UHV converter valves with the period range of 0-10s was determined, which lays a foundation for the seismic performance evaluation of the UHV converter valves.

Dynamic walking characteristics and control of four-wheel mobile robot on ultra-high voltage multi-split transmission line

High-voltage lines are an important channel for power transmission, and multi-split transmission lines are the main strength of power transmission. Compared with double-wheel single-wire maintenance robots, ultra-high-voltage multi-split transmission lines and four-wheel mobile robots have a wider application range and greater demand. The maintenance of multi-split transmission lines relies on the stable walking and control of four-wheel mobile robots on heterogeneous multi-split transmission lines. However, uncertain disturbance factors such as wind load in the complex field environment cause vibration of double-split and quad-split lines. The slight change in the line spacing causes the line contact to the edge of the robot’s walking wheel, which increases the friction during the robot’s walking. It also directly hinder the movement of the robot on the multi-split transmission line, thus restricting the completion of the robot’s maintenance operation. Based on the analysis, this paper establishes a mathematical model of the external force disturbance influence on the spacing of the double-split lines. At the same time, the robot walking mechanics characteristics model under the change of the line space has been established. Three different forms of the robot walking online have been obtained through abstraction processing. A method of side friction identification based on fuzzy control has been proposed, through the online monitoring of the friction between line and edge of the walking wheel, the robot walking wheel motor walking force can be intelligently controlled in real time, and effectively avoids the “wheel-line” jam phenomenon under the external uncertain factors in the field environment. Finally, the feasibility and engineering practicability of the method have been verified through MATLAB/ADAMS simulation and field operation experiments. Therefore, the automation and intelligence level of the operation and the transmission system maintenance management has been improved.