设计直流脉宽调速电动机系统的机械特性.pdf

设计直流脉宽调速电动机系统的机械特性 1.1 直流电动机 pwm 控制系统原理。 pwm 控制技术一直是 变频技术的核心技术之一。它通过分辨率计数器的使用，方 波的占空比被调制用来对一个具体模拟信号的电平进行编 码。 1.1 principle of dc motor PWM control system. PWM control technology has been one of the core technology of frequency conversion technology. It through the use of resolution counter, the square wave duty ratio is modulated to encode a specific analog signal level. 直流电动机 pwm 控制系统有可逆和不可逆系统之分。可逆 系统是指电动机可以正反两个方向旋转；不可逆系统是指电 动机只能单方向旋转。对于可逆系统，又可分为单极性驱动 和双极性驱动两种方式。这里只研究双极性驱动。 Dc motor PWM control system can be reversible and irreversible systems. Reversible system is refers to the motor can be positive and negative two direction; Irreversible system refers to the motor can only single direction. For reversible system and can be divided into single polar driving and double polar driving in two ways. Here only the bipolar drive. 1.2 h 型双极性可逆 pwm 驱动系统控制原理。 “h ”型是双 极性驱动电路的一种，也称为桥式电路。如图 1 所示。其电 路是由四个开关管和四个续流二极管组成，单电源供电。四 个开关管分为两组， v1 和 v4 为一组， v2 和 v3 为另一组。 同一组的开关管同步导通或关断，不同组的开关管的导通与 关断正好相反。 1.2 h bipolar reversible PWM drive system control theory. H type is one of the bipolar drive circuit, also known as the bridge circuit. As shown in figure 1. The circuit is made up of four switch tube and four of the fly-wheel diode, single power supply. Four switch tube is divided into two groups, v1 and v4 as a group, v2 and v3 for another group. The same set of synchronous conduction or shut off the switch tube, different group of conduction and shut off the switch tube of just the opposite. 在每个 pwm 周期里，当控制信号 vi1 高电平时，开