如何选择工业自动化电机？
发布时间:
2024-04-18
了解负载、电机和应用的主要类型有助于简化工业电机和附件的选择。选择工业电机时需要考虑许多方面，例如应用，操作，机械和环境问题。通常，您可以从交流电机，直流电机或伺服/步进电机中进行选择。知道使用哪一个取决于工业应用以及是否有任何特殊需求。根据电机驱动的负载类型，工业电机需要恒定或可变的扭矩和马力。负载的大小，所需的速度和加速度/减速度-尤其是在快速和/或频繁的情况下-将决定所需的扭矩和马力。还需要考虑控制电动机的速度和位置的要求。
Understanding the major types of loads, motors and applications can help simplify the selection of industrial motors and accessories. There are many aspects to consider when selecting an industrial motor, such as application, operational, mechanical and environmental issues. In general, you can choose from AC motors, DC motors or servo/stepper motors. Knowing which one to use depends on the industrial application and if there are any special needs. Depending on the type of load the motor is driving, industrial motors require a constant or variable torque and horsepower. The size of the load, the required speed and acceleration/deceleration - especially if it is fast and/or frequent - will determine the torque and horsepower required. Consideration also needs to be given to the requirements for controlling the speed and position of the motor.
There are four types of industrial automation motor loads.
1, Adjustable Horsepower and Constant Torque: Variable horsepower and constant torque applications include conveyors, cranes and geared pumps. In these applications, the torque is constant because the load is constant. The horsepower required may vary depending on the application, making constant speed AC and DC motors a good choice.
2. Variable Torque and Constant Horsepower: An example of a variable torque and constant horsepower application is a machine rewinding paper. The speed of the material remains constant, which means that the horsepower does not change. However, as the roll diameter increases, the load changes. In small systems, this is a good application for DC motors or servo motors. Regenerative power is also a concern and should be considered when sizing industrial motors or selecting energy control methods. AC motors with encoders, closed-loop control, and full-quadrant drives may benefit larger systems.
3. Adjustable horsepower and torque: Fans, centrifugal pumps, and agitators require variable horsepower and torque. As the speed of an industrial motor increases, the load output increases with the required horsepower and torque. These types of loads are the beginning of the motor efficiency discussion, inverter loaded AC motors use variable speed drives (VSDs).
4. Position control or torque control: Applications like linear drives, which need to move accurately to multiple positions, require tight position or torque control, and often require feedback to verify the correct motor position. Servo or stepper motors are the best choice for these applications, but DC motors with feedback or inverter-loaded AC motors with encoders are often used in steel or paper production lines and similar applications.
Different Industrial Motor Types
While there are more than 36 types of AC/DC motors used in industrial applications. While there are many types of motors, there is a great deal of overlap in industrial applications and the market has pushed to simplify motor selection. This has narrowed down the actual choice of motors in most applications. The six most common motor types, which are suitable for the vast majority of applications, are brushless and brushed DC motors, AC squirrel cage and wound rotor motors, servo and stepper motors. These motor types are suitable for the vast majority of applications, while the other types are only used for specialized applications.
Three Main Types of Industrial Motor Applications
工业电机的三个主要应用是恒速、变速和位置 (或转矩) 控制。不同的工业自动化情况需要不同的应用和问题以及它们自己的一系列问题。例如，如果最高速度小于电动机的基本速度，则需要齿轮箱。这还可以允许较小的马达以更有效的速度运行。虽然有大量关于如何确定电机大小的在线信息，但用户必须考虑许多因素，因为有许多细节需要考虑。计算负载惯性，扭矩和速度需要用户了解诸如负载的总质量和大小 (半径) 以及摩擦，变速箱损耗和机器循环等参数。还必须考虑负载变化、加速或减速速度以及应用的占空比，否则工业电机可能会过热。交流感应电动机是工业旋转运动应用的流行选择。在电机类型选择和尺寸确定之后，用户还需要考虑环境因素和电机外壳类型，例如用于洗涤应用的开放式框架和不锈钢外壳。
How to select an industrial motor
There are three main questions for industrial motor sizing
1. constant speed applications?
In constant speed applications, motors typically run at approximate speeds with little or no consideration for acceleration and deceleration ramps. This type of application usually operates using a full line on/off control. The control circuit usually consists of a branch circuit fuse with a contactor, an overload industrial motor starter, and a manual motor controller or soft starter. Both AC and DC motors are suitable for constant speed applications. DC motors provide full torque at zero speed and have a large mounting base. AC motors are also a good choice because they have a high power factor and require little maintenance. In contrast, the high performance characteristics of servo or stepper motors would be considered excessive for a simple application.
2. variable speed applications?
变速应用通常需要严格的速度和速度变化，以及限定的加速和减速斜坡。在实践中，降低风扇和离心泵等工业电机的速度通常是通过将功耗与负载相匹配来提高效率，而不是全速运行并节流或抑制输出。这些对于输送应用如装瓶线是非常重要的考虑因素。交流电机和VFD组合广泛用于提高效率，并在各种变速应用中很好地工作。具有适当驱动器的交流和直流电动机在变速应用中都能很好地工作。长期以来，直流电动机和驱动器配置一直是变速电动机的唯一选择，并且其组件已得到开发和验证。即使到现在，直流电动机在变速，分数马力应用中也很流行，并且在低速应用中很有用，因为它们可以在低速下提供全扭矩，在各种工业电动机速度下提供恒定扭矩。然而，直流电动机的维护是一个需要考虑的问题，因为许多需要电刷进行换向，并且由于与运动部件的联系我们而可能磨损。无刷直流电动机消除了这个问题，但它们的前期价格更高，并且可用于较小范围的工业电动机。电刷磨损不是交流感应电机的问题，变频驱动器 (vfd) 为超过1马力的应用 (如风扇和泵) 提供了一个有用的选择，可以提高效率。选择驱动类型来运行工业电机可以增加一些位置意识。如果应用程序需要，可以将编码器添加到电机中，并且可以指定驱动器使用编码器反馈。因此，这种设置可以提供类似伺服的速度。
3. Is position control required?
紧密的位置控制是通过不断验证电机的位置来实现的。诸如定位线性驱动器之类的应用可以使用具有或不具有反馈的步进电机或具有固有反馈的伺服电机。步进器以中等速度精确地移动到一个位置，然后保持该位置。开环步进系统提供强大的位置控制，如果适当的大小。当没有反馈时，步进器将移动精确的步数，除非它遇到超过其容量的负载中断。随着应用的速度和动态的增加，开环步进控制可能无法满足系统的要求，需要升级到带反馈的步进或伺服电机系统。闭环系统提供精确、高速的运动轮廓和精确的位置控制。伺服系统在高速下比步进电机提供更高的扭矩，并且在高动态负载或复杂运动应用中也可以更好地工作。对于具有低位置过冲的高性能运动，反射负载惯量应尽可能与伺服电机惯量匹配。在一些应用中，高达10:1的失配是足够的，但是1:1匹配是最佳的。齿轮减速是惯性失配问题的一个很好的解决方案，因为反射负载的惯性按比率的平方减小，但是在计算中必须考虑齿轮箱的惯性。
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