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步进电动机引进特征

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此示例显示了如何使用制造商数据表和测试安全带参数化和调整步进电机。使用从数据表中提取的数值数据进行参数化。该仿真会生成引进的扭矩特性，您可以将其与制造商提供的引进曲线进行比较。为了调整步进电机模型，该示例使用了将驱动器类型和负载参数变化的测试线束。

Test Harness

The stepper is modeled using the Stepper Motor block from the Simscape™ Electrical™ library. The stepper motor driver is modelled by a current source and a first order filter. The motor is placed in a test harness. The test harness gradually increases the load until slip occurs for each step rate demand tested. Slip detection is implemented in the Slip Detection subsystem. The subsystem contains a Simulink® assertion block that determines the difference between expected and actual rotor angle.

Pull-in Torque Characteristics

The plot shows the pull-in characteristics generated by the test harness simulation. Results are superimposed on the pull-in curve from the manufacturer datasheet. Achieving an exact match for the pull-in characteristics can be challenging because most datasheets do not specify the test conditions. Furthermore, some datasheets do not provide all the numerical values required to model the stepper motor. In this case, the pull-in curve from the simulation is used to determine for representative values that yield an acceptable pull-in curve match.

Pull-in Characteristics Sensitivity to Drive and Load Parameters

在引进模式下，步进电动机必须启动和停止而不会丢失同步。由于步进电动机的动态性质，引进的扭矩速度性能对步进运动驱动器的配置和负载参数高度敏感。

When modeling or tuning a stepper motor, consider that:

  • Increasing the load inertia reduces the stepper motor pull-in torque at higher step rates. Generally, for high step-rate operation, load inertia is less than three times that of rotor inertia. It is a generally-accepted practice to limit the load inertia to less than ten times that of rotor inertia.

  • Loads with higher damping component results in better performance at lower step rates because damping helps to overcome the effects of stepper motor resonance. Similarly, internal motor rotor damping can also help to improve the performance at low step rates.

  • Stepper motors with low winding resistance are often driven using a constant current drive. To reduce the current rise time, higher than the rated voltage is applied to the motor. The higher supply voltage yields higher pull-in torque capability at higher step rates.

  • 通常为特定驱动程序和负载配置（负载类型，负载惯性和负载阻尼）提供了制造商数据表上提供的引进扭矩曲线。制造商倾向于使用Dyno设置或通过在转子轮施加摩擦来测试步进电动机。测试方法很少包含在数据表中。因此，模拟步进电动机以生成曲线以进行参数化验证目的总是很重要的。

The plot shows how the pull-in torque is sensitive to rotor damping, drive voltage, load inertia, and load type.

For any given stepper motor, the set of model parameter values that matches the pull-in torque characteristics is not typically unique. To ensure the parameterization is representative, it is good practice to also generate and compare the pull-out curve with the datasheet.