Design and Research of the Crane Anti-collision Alarming Device against HV Transmission Wires

Abstract

The design and research of the crane anti-collision alarming device against HV transmission wires are introduced in this paper. The alarming device can receive wirelessly all the signals sent by the various electric-field sensors of the crane, and then the device can give out different indications about safety, precaution, high-voltage danger and distance warning accordingly so as to protect the high-voltage transmission wire from careless damage of the working cranes. Introduction In recent years, short circuit tripping accidents caused by high-altitude construction machinery near high-voltage wires often happened in many provinces. According to incomplete statistics, more than one hundred accident caused by cranes touching the high-voltage wires happened a year. Some caused blackouts in large area, and the national economy suffered severe losses [1-2]. That has brought great influence to people's life and social activities. Therefore, it is important to research how to effectively prevent the accident caused by the crane to touch the high voltage wire. Research statuses In the research of the crane anti-collision alarming device against HV transmission wires, there are few studies about the application of anti-collision device in the crane construction work near high-voltage power. Most of the anti-collision measures are just to develop safety scheme in detail before construction, for example, to limit tower crane to rotate in only one direction, to set the bamboo-protective barriers [3-4]. Obviously, this approach is time-consuming and laborious. It is not suitable for most of the construction work of crane. There are two types of the crane anti-collision alarming device against HV transmission wires in China. One of them is infrared detection, obtaining the position and state of the crane [5]. Another is electric induction, determining the risk by inducing the electric field around the high-voltage wire. System design The crane anti-collision alarming device against HV transmission wires described in this paper is designed based on the principle that metal produce surface induced charge in an electric field. The charges of metal surface can converted into the voltage signal. After the election of 50Hz frequency filter circuit, the signal amplifying circuit, the signal is sampled by the STM32 microcontroller. The results of the measurements are converted into distance information. The alarm information is transmitted to the alarming host by the wireless communication module NRF905. The host can remind the operator of the danger of high-voltage lines through the sound and light. The whole system is divided into signal processing module, signal acquisition module, wireless transmission module and alarm module. The system frame diagram is shown in figure 1. International Conference on Applied Science and Engineering Innovation (ASEI 2015) © 2015. The authors Published by Atlantis Press 793 Fig. 1. The system frame diagram The signal processing module. The signal processing module is the key part of the whole equipment. It is the electric field sensor before the signal processing circuit. The design of the spherical electric field sensor is complex and difficult to process. So a parallel plate is used to be an electric field sensor. A parallel plate capacitor is chosen as a power frequency electric field sensor in this paper. The PCB board is used as the electric field probe in this paper. The equivalent model of the parallel plate sensor is shown in figure 2.