交流电力测功机控制系统的研究

发布时间：2018-03-04 20:12

本文选题：测功机　切入点：PLC　出处：《武汉理工大学》2014年硕士论文　论文类型：学位论文

【摘要】：近年来，随着国内汽车工业迅速发展和环保要求日益严格，对发电机性能测试技术要求进一步提高。交流电力测功机系统能够在实验室模拟发电机安装在整车上实际运行时的机械负载，其优点在于试验条件容易控制，参数采集处理方便，测量精度高等。目前，国内外交流电力测功机控制系统技术方面存在较大的差距。因此，，研制出高水平的交流电力测功机控制系统有利于国内测功机技术的发展，并具有重要的意义。研究内容包括以下几方面。深入研究了测功机的基本结构，并分析其工作原理和数学模型，设计交流电力测功机控制系统的硬件和软件。制定出了本测功机控制系统的总体方案。在硬件设计上，以西门子S7-200PLC为主控制器，给出了转速和扭矩信号的采集和处理电路设计方法及具体的原理图。确定PLC与各部分的通讯方法和设计其通讯电路。通过MODBUS协议实现PLC与变频器之间的通讯，自由口协议实现PLC与触摸屏之间的通讯，以太网模式实现PLC与上位机之间的通讯。在软件设计上，以PLC为软件开发平台，采用计算机和人机交互技术，设计了实时控制子程序和人机交互子程序。根据交流电力测功机系统的控制要求，使用模块化进行处理。利用去除最大值和最小值后求平均值的方法对数据进行滤波处理，控制策略采用基于九点控制的PID控制，实现交流电力测功机控制系统的软件设计。对测功机系统进行了空载试验和发电状态试验。空载试验时，进行了转速信号测试试验和扭矩信号测试试验。发电状态试验，采用测功机转速给定-被测电机扭矩变化和被测电机扭矩给定-测功机转速变化的两种控制调节方案。大量的实验结果表明，基于九点控制的PID控制的交流电力测功机控制系统能够达到较理想的控制效果，满足发电机性能测试的要求。整个系统能够实现测功机转速控制、扭矩控制、转速模式下的恒扭矩控制和扭矩模式下的恒转速控制，具有较高的稳定性，模拟了被测电机的机械性能，初步完成了对测功机发电状态的研究与分析。
[Abstract]:In recent years, with the rapid development of domestic automobile industry and the increasingly stringent requirements of environmental protection, The requirements for performance testing of generators are further improved. The AC electric dynamometer system can simulate the mechanical load of the generator installed on the whole vehicle in the laboratory. Its advantage is that the test conditions are easy to control. At present, there is a big gap in the control system technology of AC electric dynamometer at home and abroad. The development of a high level AC dynamometer control system is beneficial to the development of domestic dynamometer technology and has important significance. The research contents include the following aspects. This paper studies the basic structure of dynamometer, analyzes its working principle and mathematical model, designs the hardware and software of the control system of AC electric dynamometer, and formulates the overall scheme of the control system of the dynamometer. In hardware design, Siemens S7-200 PLC is used as main controller. In this paper, the design method of the circuit for collecting and processing rotational speed and torque signals and its schematic diagram are given. The communication method and circuit between PLC and each part are determined. The communication between PLC and frequency converter is realized by MODBUS protocol. Free port protocol realizes communication between PLC and touch screen, Ethernet mode realizes communication between PLC and host computer. In software design, the real-time control subroutine and human-computer interaction subroutine are designed with PLC as the software development platform and computer and human-computer interaction technology. According to the control requirements of AC power dynamometer system, Modularization is used to process the data. The data is filtered and processed by removing the maximum value and the minimum value, and the control strategy is based on the PID control of nine points. The software design of the control system of AC power dynamometer is realized. During the no-load test, the rotational speed signal test and the torque signal test test are carried out. In this paper, two kinds of control and regulation schemes are adopted, that is, the speed of dynamometer is given-the torque change of the motor to be measured and the torque of the dynamometer to be given. A large number of experimental results show that, The control system of AC electric dynamometer based on nine-point PID control can achieve ideal control effect and meet the requirements of generator performance test. The whole system can realize the speed control of dynamometer, torque control, constant torque control under rotational speed mode and constant speed control under torque mode. The research and analysis of the power generation state of dynamometer have been preliminarily completed.
【学位授予单位】：武汉理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TP273

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