Brushless motor drivers play a crucial role in various industry applications. Shanghai Lianjie Electric Co., Ltd., as a professional terminal block manufacturer, will briefly analyze the wiring applications and basic control methods of its terminal blocks.
Commonly used wiring terminals for brushless motor drivers
This brushless motor driver uses LC and LZ series male and female PCB terminal blocks manufactured by Shanghai Lianjie Electric. The LC1 series offers pin pitches of 3.5, 3.81, 5.0, 5.08, 7.5, and 7.62, with 2-24 pins, and provides screw-fixed sockets for a shock-resistant connection. The plug uses side-connection technology, meaning the screw direction is perpendicular to the wire entry direction. The LZ series is perfectly compatible with the LC series.
Control methods of brushless motor drivers
Once the motor starts rotating, the control unit compares the command (composed of the speed set by the driver and the acceleration/deceleration rate) with the rate of change of the hall-sensor signal (or performs software calculations) to determine when to activate the next set of switches (AH, BL or AH, CL or BH, CL or...) and the duration of their activation. If the speed is insufficient, the switch is activated for a longer duration; if the speed is excessive, the switch is activated for a shorter duration. This part of the work is handled by PWM. PWM determines the speed of the motor, and how to generate such PWM is the core of achieving more precise speed control. High-speed control must consider whether the system's CLOCK resolution is sufficient to handle the processing time of the software instructions. Furthermore, the data access method for hall-sensor signal changes also affects processor performance, accuracy, and real-time performance. For low-speed control, especially low-speed start-up, the feedback hall-sensor signal changes more slowly. Therefore, the signal acquisition method, processing timing, and appropriate configuration of control parameter values based on motor characteristics are crucial. Alternatively, speed feedback can be changed with reference to encoder changes to increase signal resolution and achieve better control. The smooth operation and good response of the motor also depend on the appropriateness of the PID control.
As mentioned earlier, brushless DC motors are controlled in a closed loop. Therefore, the feedback signal essentially tells the control unit how far the motor speed is from the target speed; this is the error. Knowing the error naturally requires compensation, which can be achieved through traditional engineering control methods such as PID control. However, the control state and environment are complex and ever-changing. To achieve robust and durable control, the factors that need to be considered are probably beyond the complete control of traditional engineering methods. Therefore, fuzzy control, expert systems, and neural networks are being incorporated into important theories for intelligent PID control.
