【作者】 幸晋渝；

【导师】 刘念；

【作者基本信息】 四川大学 ， 电机与电器， 2005， 硕士

【摘要】 断路器作为电力系统中重要的电气设备之一,起着控制、调节和保护作用,其可靠性和智能化水平对电力系统的稳定和自动化程度将产生深远的影响。伴随着电网的不断扩大,用户对供电质量和供电可靠性要求也越来越高。电能的高质量体现在电压和频率的稳定性、电压畸变率、暂态过程长短等多个方面。在配电网中,断路器操作频繁,产生大量的操作暂态过程,直接影响了电能质量。由于真空断路器技术的日益进步和显著优点,使得真空断路器在配电系统中得到越来越广泛的应用。因此,针对真空断路器操作过电压的抑制问题,开展真空断路器智能同步操作的研究,对电力系统的安全运行和电能质量的提高具有重要的现实意义。 本文在分析和总结国内外断路器智能化研究现状的基础上,对真空断路器操作过电压进行了理论分析,研究了永磁机构动作时间的影响因素,提出了基于DSP和人工神经网络的同步控制解决方案,给出了一种在断路器上直接获取电网参数的算法。 针对该研究课题,本文的主要研究内容如下: 1、对真空断路器操作过电压进行了详细的理论分析。阐述了各种情况下操作过电压的形成及抑制方法;分别对空载变压器、电容器和空载线路的合、分闸操作过电压进行了讨论。 2、介绍了双稳态永磁机构的工作原理,在分析永磁机构动作时间影响因素的基础上,提出了利用人工神经网络建模预测分、合闸时间及其在DSP上的实现方法。在分析操作暂态过程的基础上,给出了合、分闸操作时的信更多还原

【Abstract】 As one of the important electrical equipment, the circuit breaker controls, adjusts and protects power system. The reliability and intelligence degree of circuit breaker greatly influence the stabilization and automation degree of power system. With the continuous expanding of power grid, consumers demand higher power quality and dependability. The high quality of power is indicated by the stability of voltage and frequency, distortion rate of voltage, transient process and so on. Frequent operation of circuit breaker causes a lot of operating transient process which directly affect power quality in distribution power system. Because of the increasing technology progresses and remarkable advantages of Vacuum circuit breaker, it is used more and more widely in distribution power system. Therefore, the study of intelligent synchronous operation of vacuum circuit breaker, aiming at suppressing operation of over-voltage is of great practical significance for safety operation of power systems and improvement of power quality.Based on the analysis and summarizing of research status of circuit breaker intelligence at home and abroad, this paper makes a theoretical analysis on operating over-voltage produced by switching vacuum circuit breaker, studies the influential factor for acting time of permanent magnetic actuator and presents a feasible approach to accomplishing the intelligent synchronous operation basedon DSP and artificial neural network. The calculation method of the electrical parameter of power system is also proposed.In connection with this subject, the main contents are described as follows:1. A theoretical analysis on operating over-voltage of vacuum circuit breaker is made in detail. The reason and suppressing means to operating over-voltage are described in all situations. Over-voltage when switching unloaded transformer, power capacitor, unloaded transmission lines is discussed respectively.2. The working principle of bio-stable permanent magnetic actuator is introduced in this paper. A feasible approach to making mathematical model to predict the closing and cutting time and the implement method of the model with DSP are proposed, based on analyzing the factors which influence the acting time of permanent magnetic actuator and on the use of artificial neural network. The means to predict zero point of signal and the whole project for synchronous operation are proposed as well.3. The sampling and calculation methods of the electrical parameter in power system are proposed. In this paper, a group of filter operator is introduced to estimate the parameter of decaying DC component online. A technique to calculate the fundamental frequency and harmonics component in the signal is proposed based on evaluation of the decaying DC offsets. The data windows just need one fundamental cycle, so this technique has high speed. In theory, this technique is an accurate algorithm.4. Making use of MATLAB software, operating over-voltage caused by closing unloaded transformer is simulated. A mathematical model is built to predict the closing time on the base of MATLAB artificial neural network tool. Simulation results adopted traditional DFT and this technique show the effectives of this technique to calculate the electrical parameter in power system.This paper proposes the method of intelligent synchronous controller of circuit breaker with permanent magnetic actuator, which adopts a fast algorithm to deal with signal and combines DSP and artificial neural network. It contributes, to some extend, to the improvement of power quality and the implement of integrated automation of distribution power system.更多还原