【作者】 刘建国；

【导师】 张桂香；

【作者基本信息】 湖南大学 ， 机械电子工程， 2004， 硕士

【摘要】 近年来，国内汽车工业发展和环境保护日趋严格对发动机性能测试技术提出了更高的要求。本文以发动机测试中一项重要的特性测试项目——速度特性测试为目的，重点研究了交流电力测功机及其控制系统设计。在详细分析测功机工作原理和稳定性的基础上，以“被测发动机—电力测功机—负载电阻”为研究对象，开展了测功电机数学模型、电力测功机带纯阻性负载运行电枢反应分析、控制系统硬件设计、控制策略以及软件设计等方面的研究，完成了电力测功机控制系统开发。 首先，以电力测功机为中心，分析了测功原理及系统各主要转矩量之间的关系，讨论了测功系统稳定运行条件。利用坐标变换和Park方程得出测功电机模型，并运用电机学理论对测功电机运行时的电枢反应进行了详细研究，推导了测功电机电磁转矩控制基本方程式，对系统负载控制作了定量分析，为测功系统负载控制策略奠定了基础。 在硬件设计上，以工业控制计算机为核心，给出了转矩、转速、电流、电压等信号检测和处理电路的设计方法和具体的原理图，讨论了控制系统重要的组成部分——负载电阻调节与励磁控制系统的设计与实现：在控制策略上，确定了调节“负载电阻”和“励磁电流”、串级控制等电力测功机系统负载调节方式，将参数自整定模糊PID控制应用于转速闭环控制，进行了控制算法研究；最后，利用虚拟仪器技术，以LabVIEW和VC++为开发平台，实现了电力测功机控制系统的软件设计。 大量的实验结果表明，基于LabVIEW和模糊PID控制的电力测功机控制系统具有较理想的控制效果，满足发动机速度特性测试的要求。更多还原

【Abstract】 Recently, with the development of the domestic automotive industry and the stricter policy of environment protection, higher-level test technologies are required for the engine test. Aiming at the speed characteristics test, which is one of important test items of engine test, this paper proposes studies of AC electrical dynamometer and its control system. Based on the detailed analysis of operating principle and stability of the electrical dynamometer system, the paper chooses the tested engine, electrical dynamometer and load resistance etc. as research object, mainly studies the modeling of electrical dynamometer, the design of the hardware and software of the control system, as well as the control strategy and the armature reactor analysis of electrical dynamometer when the electrical dynamometer runs with pure resistive load. The development of the control system of the electrical dynamometer is also completed.In this paper, after discussing about the operating principle and the relations among the main torques of electrical dynamometer system, the stability conditions of the system function are analyzed. The electrical dynamometer model is constructed through coordinate transformation and Park equation. The armature reactor of electrical dynamometer is also explored in detail as it runs with pure resistive load. The elementary equation about electromagnetism torque is deduced, and the quantitative analysis of the load control of the system is also carried out. These steps have laid the base of load control strategy for the power-test system.As to the design of hardware of control system, taking industry control computer as its core, the design methods and practical used circuit diagrams are presented to detect the torque, rotation speed, current, voltage, etc. The design of the load resistance regulating and the excitation control system is also presented in detail, which is an important part of power-test control system. For the control strategy of the system, the regulation of cascade control is employed to control the load of power-test system, load resistance and excitation current. And the auto-tuning parameter Fuzzy PID control is applied to the closed-loop control of rotation speed; the corresponding algorithm is studied in detail. Finally, the softwareparts of the electrical dynamometer control system are realized by using Lab VIEW and VC++.A lot of experiment results show that the control system of electrical dynamometer, which is based on LabVIEW and Fuzzy-PID control, possesses satisfactory performance to meet the requirement of engine speed characteristics test.更多还原