Dong Enyuan

The analysis of high-speed repulsion actuator and performance comparisons with permanent magnetic actuator in vacuum circuit breaker

The high-speed operation switchgears are required by more and more situations in power system, such as high-speed DC circuit breaker and some power-transfer locations. In this paper, a novel vacuum circuit breaker with high-speed repulsion actuator is designed, where, the characteristics of high-speed repulsion actuator are analyzed with finite element method (FEM) through changing design parameters of repulsion actuator, and good trends for generating bigger force are given. The performance comparisons with permanent magnetic actuator (PMA) are also given in this paper, experiments shows that vacuum circuit breaker (VCB) based on high-speed repulsion actuator can present good operate performance than PMA.

Permanent magnet actuator and electronic drive for vacuum switches

The permanent magnet actuator (PMA) is a new drive system for vacuum switches, it is the key technology to the transformation from mechanic driver to electronic driver. After discussion on the concept of an electronic driver, an equivalent circuit of a typical PMA is given first, an optimized energizing current is proposed, that needs a minimum pulsed power source. Then the reliability of a PMA system is discussed.

Arc tracking properties of the aging wires in aircraft

A modern commercial aircraft contains hundreds of miles of wiring. This vastly increased use of wiring, in conjunction with decreased insulation thickness, has increased the incidence of wire-related aircraft safety problems. Due to thermal, electrical, mechanical and chemical overstress, the aircraft wiring will be aged and the wire insulation will be decreased. Microscopic cracking occurs in wire insulation as the insulation ages. The Cracking in the wire insulation can lead to arc burning between metal conductors in aircraft wiring system. Aging wiring and associated deterioration of the insulation increases the potential for arc fault phenomenon to occur in aircraft. In order to investigate fault arc behaviour of the aging wire, the arc tracking tests have been performed with typical aircraft wire BMS 13-60. The video of the arc burning and the waveform of the fault arc have been recorded. The primary test results indicate that wire aging has an important influence on the fault arc behaviour.

Aviation arc fault diagnosis based on weight direct determined neural network

A diagnosis method for the aviation fault arc is proposed in this paper, which is a multi-input weights direct determination (WDD) network. Characteristics of arc current are used for aviation arc fault detection. Arc fault samples are acquired with the help of a self-made arc generator. Feature vectors are obtained from the current of the samples with the wavelet transforming. After training, the fault diagnosis network is verified with the test samples. The result shows that the method has a better performance for aviation fault arc recognition with a simple algorithm.

Researches on Vacuum Arc Images Based on Digital Image Processing

Image character information of vacuum switching arc images has great influence on the breaking capacities of vacuum circuit breakers (VCB), then how to extract features from the vacuum switching arc images has become an important issue in the field of vacuum arc basic theory. In this paper, an experimental setup of vacuum switching arc and an image collection system using high resolution CCD camera are designed, vacuum arc images can be collected when the arc is triggered by the triggering circuit. The distribution of temperature can be described using Gray-contour based on digital image processing with MATLAB, at the same time in course of image enhancement processing, by the means of spatial enhancement, histogram processing, color enhancement, both detail information and textural information of vacuum switching arc images can be reflected. It has been proven that using image processing techniques lots of characteristics of images of vacuum switching arc can be enhanced and embodied.