摘要：直流电机调速系统不仅能在大范围内平滑调速，而且具备优良的起动和制动性能，当控制系统设计得当时，可使电机在四象限内快速过渡和稳定运行，在一些高性能要求的电力传动领域内得到了广泛的应用。目前，虽然交流调速技术发展也很快，并有逐渐取代直流调速系统的趋势。然而，从理论和实践的角度看，直流调速系统起步早，仍然比较成熟，它又是交流调速系统研究的基石。所以，直流调速系统的地位是不可替代的。

传统的晶闸管-电动机（V-M）系统很难实现电机的可逆运行，而且电机在低速时系统功率因数差，还容易在交流侧产生较大的谐波电流，引起电网电压畸变的一系列问题。与传统的将直流电压直接加在电机电枢两端不同，本文描述的双闭环PWM可逆直流调速系统是先将工业三相交流电源整流为直流电源，然后根据控制电路的要求通过PWM逆变主电路把直流电源调制成一高频率的正负相间的脉冲宽度可调的交变电压序列，再加到直流电动机电枢两端，从而完美地实现了电机的四象限运行。

本文从组织结构上主要分两大部分，第一部分介绍一些模块的基本原理，同时计算出了相关的参数；第二部分是根据第一部分计算得到的参数建立SIMULINK仿真模型，并展示和分析了仿真的结果。结果证明设计的直流调速系统不仅可以实现电机四象限运行，且具有优良的静特性和动态性能，以及抗扰性能。

关键词：PWM；双闭环；整流

Abstract：DC motor speed control system not only in a wide range of smooth speed control, and has excellent starting and braking performance. When the control system is designed, the motor can quickly transition and stabilize the operation in four quadrants. In a number of high-performance requirements of the field of power transmission has been widely used. At present, although the exchange of speed control technology is also very fast, and gradually replace the DC speed control system trends. However, from the theoretical and practical point of view, the DC speed control system started early, still relatively mature, it is the cornerstone of AC speed control system. Therefore, the status of DC speed control system is irreplaceable.

The traditional thyristor-motor (V-M) system has caused a series of problems. It is difficult to achieve the motor reversible operation, and the motor at low speed system power factor is poor, but also easy to produce a large harmonic current in the AC side, causing the voltage distortion of the grid. With the traditional DC voltage will be added directly to the motor armature at both ends. This article describes the dual closed-loop PWM reversible DC speed control system is the first three-phase industrial power supply rectifier DC power supply, and then according to the requirements of the control circuit, through the PWM inverter main circuit to DC power modulation into alternating voltage sequence. The frequency of the voltage sequence is very high, positive and negative polarity phase, and the pulse width is adjustable. And then add the voltage sequence to both ends of the DC motor armature, so as to achieve the perfect four-quadrant motor operation.

This article from the organizational structure is mainly pided into two parts. The first part introduces the basic principle of some modules and calculates the relevant parameters. The second part is based on the first part of the calculated parameters to establish SIMULINK simulation model, and show and analyze the simulation results. The results show that the designed DC speed control system can not only realize the four-quadrant operation of the motor, but also has excellent static and dynamic performance, as well as the anti-interference performance.

Keywords: PWM; double closed loop; rectifier

目录

第一章绪论