Phase number identification of stepper motor - Solutions - Huaqiang Electronic Network

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The number of motor phases refers to the number of coil groups inside the motor. Currently, two-phase, three-phase, and five-phase stepping motors are commonly used. The 2-phase stepper motor indicates the number of coil sets used. The 3-phase stepper motor uses 3 sets of coils. 2-phase stepper motor, 3-phase stepper motor is generally a set of four coils. 2*4 is 8 coils corresponding to 3*4 and 12 coils. The 5-phase stepping motor has two coils in one group. (N pole, S pole two pairs).

The number of phases of the motor is different, and the step angle is also different. Generally, the step angle of the two-phase motor is 0.9°/1.8°, the three-phase is 0.75°/1.5°, and the five-phase is 0.36°/0.72°. When there is no subdivision driver, the user mainly chooses the stepping motor with different phase numbers to meet the requirements of the step angle. If you use a subdivision driver, the 'phase number' will become meaningless, and the user can change the step angle by simply changing the number of subdivisions on the drive.

Inherent step angle of the motor:

It represents the angle at which the motor rotates each time the control system sends a step pulse signal. The motor is given a step angle value when shipped from the factory. For example, the value of the Xingfengyuan FY86EF282A motor is 0.9°/1.8° (0.9° for half-step operation and 1.8° for full-step operation). The step angle can be called the 'inherent step angle' of the motor. It is not necessarily the true step angle of the actual working of the motor. The true step angle is related to the driver.

Hold torque (HOLDINGTORQUE):

It refers to the moment that the stator locks the rotor when the stepper motor is energized but does not rotate. It is one of the most important parameters of a stepper motor. Usually, the torque of the stepper motor at low speed is close to the holding torque. Since the output torque of the stepping motor is continuously attenuated as the speed increases, the output power also changes with the increase of the speed, so the holding torque becomes one of the most important parameters for measuring the stepping motor. For example, when people say that a 2N.m stepper motor, unless otherwise specified, is a stepper motor that maintains a torque of 2N.m.

DETENTTORQUE:

It refers to the moment that the stator locks the rotor when the stepper motor is not energized. DETENTTORQUE does not have a unified translation method in China, which is easy to misunderstand. Since the rotor of the reactive stepping motor is not a permanent magnet material, it does not have DETENTTORQUE.

Static torque selection:

The dynamic torque of the stepper motor is difficult to determine at once. We often determine the static torque of the motor first. The static torque selection is based on the load on which the motor operates, and the load can be divided into two types: inertial load and friction load. A single inertia load and a single friction load are not present. When starting directly (generally by low speed), both loads should be considered. When starting acceleration, the inertia load is mainly considered. For constant speed operation, only the friction load should be considered. Under normal circumstances, the static torque should be 2-3 times of the friction load. Once the static torque is selected, the base and length of the motor can be determined (geometric size).

Torque and power conversion:

Stepper motors are generally used in a wide range of speeds, and their power is variable. Generally, they are only measured by torque. The torque and power are converted as follows:

P=Ω•MΩ=2π•n/60P=2πnM/60

P is the unit of power in watts, Ω is the angular velocity per second, the unit is radians, n is the speed per minute, and M is the unit of torque in Newton meters.

P=2Ï€fM/400 (half step work)

Where f is the number of pulses per second (referred to as PPS)