Adaptive Safety Early Warning Device for Non-contact Measurement of HVDC Electric Field

Abstract

In order to prevent electric shock accidents during the maintenance and repair of high-voltage direct current (DC) live equipment, an intelligent safety early warning system device based on non-contact electric field measurement is developed in this paper, to ensure the life safety of electrical workers and the stable operation of equipment. Firstly, the self-developed electric field sensor is used to measure the electric field strength of the space around the charged device. The STM32 microprocessor in the sensor will compare the measured electric field value with a preset safety threshold. If the safety threshold is exceeded, the early warning device issues an audible alarm. It prompts the electric power operator to exit to a safe distance. In addition, the alarm prompt symbol and the real-time waveform of the measured electric field can be seen intuitively on the mobile smart APP interface. Secondly, for devices with different voltage levels, the sensor electric field measurement range and sensitivity can be dynamically adjusted by changing the motor speed. In addition, according to the voltage level identification algorithm, this is also to achieve an adaptive safety early warning of different live equipment. Finally, field experiments were performed at a ±500 kV DC converter station and an ±800 kV DC transmission line experimental platform. The measured values of the electric field are basically consistent with the simulated values, and the safety early warning device has no false positives or false negatives during the test. The experimental results show that the design of the safety warning device in this paper meets the actual needs, and it can alert the electric workers to the specified safety distance.

Online Fault Detection of Dry Reactor Based on Improved Kalman Filter

“…Special detection work is carried out to prevent accidents to a certain extent (Figure 1). However, regular offline maintenance is mainly adopted, which has many disadvantages: (1) regular outage maintenance is required, which inevitably leads to power interruption and economic losses; (2) the actual state of power equipment is not fully considered, if the excessive maintenance will cause waste of manpower and material resources, but insufficient maintenance may directly lead to the occurrence of failure; (3) during operation, the operation state of dry reactor cannot be monitored and warned, and maintenance cannot be arranged reasonably in the early stage of failure, which may lead to the expansion of the fault range; (4) the actual test conditions cannot be completely consistent with the operating conditions of the equipment, so the reliability of the test results cannot be guaranteed. Compared with offline regular maintenance, the use of live line detection technology can not only timely warn the initial failure of equipment, but also master the development trend of dry resistance operation state.…”

Research on the Three‐Dimensional Power Frequency Electric Field Measurement System

“…Electric field measurement is of great significance in many fields of scientific research and engineering technology, such as the measurement of the pulsed electric field of defense technology nuclear explosion, the real-time monitoring of lightning transient electric field in the aerospace field, the field detection of medical equipment in the power medical industry, and the field of communication near-field measurement of mid-antenna and biological effects of the bioelectric field [1][2][3][4][5]. The electric field measurement technology gives strong support for the above fields, especially for the power systems [6][7][8].…”

A Feasibility Study of the Application of Signal Processing Techniques to Corona Discharge Characterization on HVDC Systems

“…High-voltage direct-current (HVDC) systems are emerging as a promising technology for long-distance bulk power delivery due to their lower cost and reliability compared to high-voltage alternating-current (HVAC) systems [1][2][3][4]. In this context, the measurement of corona current plays an essential role within HVDC systems since it provides important information, such as corona discharge occurrence, electromagnetic interferences HV, and electrical current intensity, among other features [5][6][7][8][9]. Owing to that, researchers have made efforts to promote new strategies of monitoring and inspection of HVDC systems through the use of contact and non-contact measurement solutions.…”

“…Owing to that, researchers have made efforts to promote new strategies of monitoring and inspection of HVDC systems through the use of contact and non-contact measurement solutions. Accordingly, many approaches have been proposed to establish the HVDC detection based on the development of corona current measurement sensing devices [6,[9][10][11], and electromagnetic field measurement sensing devices [4,5,7,12].…”