Due to the lack of current generation in the secondary circuit of zero sequence current transformers in normal operation of substations,it is impossible to effectively detect the integrity of the secondary circuit of zero sequence current during operation. When the secondary circuit of the zero sequence current transformer is open or there is a fault in the circuit shunt,it may lead to protection failure and power grid overstepping accidents. A new live detection device has been developed to detect the integrity of the secondary circuit of a zero sequence current transformer. The device applies a high-frequency excitation signal by binding an iron core coil on one side of the secondary circuit,collects and analyzes the response current of the signal on the other side,diagnoses the open circuit and multi-point grounding faults of the secondary circuit of the zero sequence current transformer,judges the polarity consistency of the transformer,displays and issues a warning in real time,effectively improving the efficiency of distribution network operation and maintenance.
With the rapid development of intelligence,the function of the whole vehicle is becoming more and more complex. More and more cameras,millimeter-wave radars,laser radars,ultrasonic sensors,and various other data acquisition devices are equipped on ve-hicles to support the evolution of autonomous driving capabilities. Compared with the wave of computing chip research and develop-ment,the development of computing chip testing and certification capabilities has seriously lagged behind. In this paper,a set of com-puting power test system is built based on TDA4VM development board. This method measures the actual computing power of the chip under the premise that the AI computing unit of the computing chip is squeezed to the maximum extent. It provides a new method for the calculation force test of the car-level computing chip. It analyzes the influence of the impact factor on the calculation of the model. It forms an independent and controllable test and evaluation ability of the vehicle computing chip,and supports the chip selection of the car manufacturers.
An electronic transformer using IR2155 has the advantages of simple structure, high output power, large current conduction angle and stable work, but it has no regulating function. When the alternating voltage range is from 180 to 250 V, output voltage also changes, so its use is limited. This paper presents the integration of APFC rectifying mode into an electronic transformer. This electronic transformer can work over a wide voltage range from 180 to 250 V; it can stabilize output voltage and has a high power factor, high output voltage, and requires only simple maintenance as well.
Three-dimensional reconstruction refers to the establishment of a mathematical model suitable for computer representation and processing of three-dimensional objects. It is not only the basis of processing, operating and analyzing its nature in the computer environment, but also the key technology of establishing virtual reality to express the objective world in the computer. Therefore, 3D reconstruction is a common scientific problem and core technology in the fields of computer aided geometric design (CAGD), computer graphics (CG), computer animation, computer vision, medical image processing, scientific computing and virtual reality, digital media creation and so on. In recent years, although many algorithms for 3D reconstruction of sequence images have been proposed, the accuracy for 3D reconstruction is still the main problem. In this paper, a new method for 3D reconstruction of sequence images is proposed. Firstly, the Harris feature extraction algorithm is improved to extract more accurate feature points. Then the extracted feature points are tracked in the sequence images. Lastly, the estimated sample consistency algorithm is used for 3D reconstruction after sparse and dense reconstruction. The experiments demonstrate that the accuracy of 3D reconstruction of sequence images is improved.
5G移动通信技术的应用与推广能够给用户提供更高质量的通信服务，节约通信成本，提升数据传输速度，给人们的生活和工作带来更多便利。信息化时代的今天，广播电视已经无法满足人们随时随地观看视频的需求，需要工作人员对广播电视技术进行不断创新，给人们提供更加优质的服务，丰富人们的业余生活。本文主要介绍在广播电视技术领域应用5G技术的必要性以及应用要点，并对其未来的发展趋势进行分析。
