Three-phase hybrid stepping motor and driver interference solution - Database & Sql Blog Articles

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The three-phase hybrid stepping motor operates on the principle of AC servo control. This type of motor, along with its driver, combines the advantages of traditional stepping motors. It delivers high torque even at a high speed ratio of 50%, and maintains excellent stability at low speeds with minimal resonance. The driver supports a single-phase 220V/50Hz input, with a three-phase sinusoidal output. It allows for adjustable output current, offers ten sub-divisions, and includes a half-flow function that reduces the rated current to 60%. The control modes are flexible, supporting both "pulse + direction" and "positive rotary pulse + reverse pulse" configurations. Additionally, it features overheat protection, making it easy to use in various applications.

However, this system can interfere with highly sensitive receiver systems due to the driver's output of 3A at 325V, combined with an unshielded casing made of non-magnetic materials like aluminum, titanium, or magnesium. This interference can disrupt the power supply and cause communication issues between the MCU and the host computer. In severe cases, it may even lead to MCU crashes, making normal operation difficult. Therefore, addressing the interference problem is essential.

To mitigate these issues, several measures were implemented in the system. First, we reduced AC power supply pollution by installing a power filter and ensuring good contact. We also followed the "one-point grounding" principle. The ground from the power filter was isolated, and the drive’s PE ground (connected to the chassis bottom plate) was properly grounded. Control signals such as PULSE- and DIR- were shorted, and the motor ground wire, along with the cable between the driver and motor, were connected to the wall’s grounding post to prevent signal crossover. For example, when placing two drive units in the same chassis for a dual-axis system, we arranged them so that the UVW motor lines were spaced apart. One driver faced forward while the other faced backward, minimizing the length of the leads. Alternatively, we routed the power cord outside to reduce internal interference.

Finally, we used shielded cables to further reduce external interference. These steps significantly improved system performance and ensured stable operation, even in environments where electromagnetic interference could be problematic.