BLDC Motor Speed Control Using SPID to Cut Overshoot
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing BLDC motor control systems using traditional PID controllers are highly dependent on gain parameter selection, leading to performance declines and issues such as slow response, excessive overshoot, and reduced anti-interference capability.
Innovation Solution
Implementing a squared proportional integral derivative (SPID) controller that integrates a squared error term and employs a threshold for enabling the derivative term, determining the gain coefficient's sign based on the error and enabling the derivative term only after the system reaches the target speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If traditional PID controller is used for BLDC motor speed regulation, then the control structure remains simple and easy to implement, but the response speed is slow and overshoot is excessive
Solution Approach 1:
The patent modifies the traditional PID controller by introducing a squared error term with gain coefficient KS, transforming the control law from linear to nonlinear. This parameter change in the error term structure enables faster response speed and reduced overshoot while maintaining the basic PID framework
Solution Approach 2:
The patent implements dynamic switching of the derivative term based on whether the motor speed has reached the target speed. The derivative term is enabled only after the target speed is reached, creating a dynamic control structure that adapts to different operating phases, thereby improving response characteristics without excessive complexity
2Reliability
If traditional PID controller is used for BLDC motor speed regulation, then the control implementation remains straightforward, but the system anti-interference capability is reduced
Solution Approach 1:
By introducing the squared error term with variable gain coefficient KS (which changes sign based on error polarity), the controller gains enhanced anti-interference capability. The nonlinear parameter transformation makes the system more robust against disturbances while maintaining implementation feasibility
3Loss of time
If traditional PID controller is used for BLDC motor speed regulation, then the control algorithm remains simple, but the system stabilization time is prolonged
Solution Approach 1:
The squared error term with gain coefficient KS accelerates the convergence rate by emphasizing large errors more strongly. This parameter transformation reduces stabilization time significantly while keeping the controller structure relatively simple
Solution Approach 2:
The dynamic enabling of the derivative term after target speed is reached provides additional damping effect precisely when needed, accelerating stabilization without causing early oscillations, thus reducing overall stabilization time
4Adaptability or versatility
If traditional PID controller is used for BLDC motor speed regulation, then the gain parameters remain constant, but the control performance declines under varying conditions
Solution Approach 1:
The gain coefficient KS of the squared error term changes dynamically based on the sign of the error, providing adaptive control behavior. This parameter adaptation improves performance under varying conditions while maintaining a relatively simple controller structure
Solution Approach 2:
The derivative term is dynamically enabled/disabled based on whether the target speed is reached, creating an adaptive control strategy that adjusts to different operating phases, thereby improving versatility without excessive complexity
Data Source
AI summary
Provided is a brushless direct current (BLDC) motor control method based on an improved proportional integral derivative (PID) controller, relating to the field of motor control. The method of this application comprises: establishing a squared proportional integral derivative (SPID) controller integrating a squared error term; determining a sign of a gain coefficient of the squared error term in the SPID controller based on an error between an actual speed and a target speed of a BLDC motor; determining whether to enable a derivative term of the SPID controller based on whether the actual speed has reached the target speed; using the error between the actual speed and the target speed as an input amount to the SPID controller, and outputting a current control amount; and performing speed control on the BLDC motor based on the current control amount until the error meets an accuracy requirement.