Du Taihang

The research on electrical life test condition of relay with electromotor load

This paper presents research on the condition of voltage and current when the relay, loaded with an AC single-phase asynchronous motor (SPAYM), turns on and off. According to the arc model and equivalent model of SPAYM during its operation, the dynamic changing process of voltage across the contacts and loop current (when the relay turns on and off) are theoretically analysed and simulated by means of a computer. Furthermore, the conclusions are compared with the actual measured results. The electrical life test condition of relay is consequently obtained from this. Finally, a computer control test device is presented.

A fusion algorithm for PAPR reduction in OFDM system

Partial transmit sequence (PTS) is a widely accepted method in reducing PAPR of OFDM signal. While traditional optimal PTS (OPTS) technique requires an exhaustive search over and computation is huge. In this paper, a fusion algorithm based on modified interleaved partition PTS and nonlinear companding transformation is presented. The algorithm set a threshold in IPTS and combine the companding transformation to reduce the computational complexity. It can achieve the same PAPR performance but at lower computational complexity compared with IPTS and companding transformation.

Study on Simulation of Cold-Rolling Fuzzy PID Control Technology

Using of the electric motor control system and the principle of rolling plastic deformation ¿this paper describes the stable state mathematical model of cold rolling process is established. The dynamic process of cold rolling is simulated by using the MATLAB/ Simulink. Cold rolling control system exists time-delay, time-varying, large inertia, nonlinear and other problems. Setting parameters of traditional PID controller is difficult. This paper put forward a method which combines structure of a fuzzy control and PID control. By MATLAB simulating, results show that static and dynamic performance of fuzzy adaptive PID controller is better than the traditional PID controller.

The Technology of Contact Image Acquisition and Progressing in Relay Electrical Endurance Test

Electrical endurance of relay has been an important work which people study. In this paper, the composition of relay contact image collection system and contact obtained technology based on the LabVIEW platform are introduced. Clearly contact photos are obtained by MATLAB image processing module. The contact electrical erosion and the changes of the contact surface between the two pull in experiments are viewed. The paper make the image acquisition and processing technology in relay electrical endurance test, so the properties of the system real-time collection are fully displayed and electric life visualization are achieved. Large quantity of man power and material resources are saved.

Evolutionary algorithm and its application in structural topology optimization

This paper proposes a bio-inspired evolutionary computational algorithm for structure topology optimization. It integrates the merits of evolutionary structure optimization and level set method for structure topology optimization. Traditional Level Set Method algorithm depends on the initial topology to some extent. New holes cannot be evolved within the updated topology during the optimization iteration. The algorithm proposed in this paper combines the merits of ESO techniques with that of LSM scheme, allowing new holes to be automatically inserted in regions with low deformation energy at prescribed iterations of the optimization. The nodal neighboring region is adopted in the proposed algorithm. Numerical example shows that good result can be gotten through less optimization iteration. The approach can solve complex structures easily, in which holes cannot be properly layed out in advance. The proposed method considerably improves the ability of LSM to find the optimal topology. The validity and efficiency of the proposed algorithm are supported by some benchmark examples in this paper.

Intelligent computation algorithm in structural design optimization

An intelligent computational algorithm is proposed for structure topology optimization in this paper. It integrates the merits of evolutionary structure optimization (ESO) and level set method (LSM), and overcome some drawbacks in traditional LSM algorithm. The established algorithm allows new holes to be automatically inserted in regions with low deformation energy during optimization and thus the final optimal topology configuration is independent of initial structural topology. Compared with evolutionary structure optimization for structure optimization, the final topology possesses smooth boundary. The new algorithm is efficient for structures that have complex boundaries. The validity and robustness are supported by some benchmark problems in topology optimization.

Design and Simulation of Excitation Control System for AC-Excited Generator

In this paper, the excitation control system of ACEG (AC excitation generator) is studied. The mathematical model for ACEG based on Park equation and the mathematics model of cycloconverter is given. And with these mathematical models, the performance of ACEG is simulated. Second, the control strategy of the excitation system is discussed. At last, a new practical scheme of excitation control system is given and some simulation results are presented.