Motor Drive Control Resonance Suppression via Timing Adjustment
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Solution Overview
Problem
Existing motor control devices face challenges in suppressing vibration-induced noise due to resonance with the natural frequency of motors, especially in axial flow fan motors, and require costly high-processing-capability microcomputers to adjust modulation rates effectively.
Innovation Solution
A motor driving control device that includes a motor driving unit, a rotational position detecting circuit, and a controller, which outputs specific drive control signals to adjust energization switching and reduce resonance between the motor's natural frequency and rotational components based on detected rotational positions, allowing for efficient resonance suppression without the need for high-cost microcomputers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If modulation rate adjustment is performed at each PWM signal frequency to suppress resonance, then vibration and noise are reduced, but processing capability requirements increase and cost rises
Solution Approach 1:
The patent extracts only the essential adjustment actions needed to suppress resonance - specifically advance angle adjustment and delay angle adjustment - from the complex modulation rate adjustment process. By focusing on these two specific timing adjustments rather than comprehensive modulation rate control, the system achieves vibration suppression with simpler processing requirements and lower cost.
Solution Approach 2:
Instead of adjusting modulation rate to avoid resonance frequencies, the patent inverts the approach by adjusting energization timing (advance and delay angles) to actively counteract the resonance effect. This timing-based adjustment method achieves the same vibration suppression goal but with simpler control logic and processing requirements.
2Object-affected harmful factors
If resonance suppression control is continuously applied across all rotational speeds, then vibration is minimized, but processing load and system complexity increase
Solution Approach 1:
The patent applies resonance suppression control selectively only in the specific rotational speed range where resonance occurs, rather than continuously across all speeds. The controller determines whether the current rotational speed falls within the resonance range and applies advance/delay angle adjustments only when needed, reducing unnecessary processing load and system complexity while maintaining effective vibration suppression where required.
3Object-affected harmful factors
If advance angle and delay angle adjustments are repeatedly performed to reduce resonance, then electromagnetic vibration is suppressed, but processing operations increase
Solution Approach 1:
The patent implements periodic action by alternating between advance angle adjustment and delay angle adjustment in a repeating cycle. This periodic alternation effectively suppresses electromagnetic vibration through consistent timing modifications while maintaining predictable and efficient processing operations, as the controller follows a regular pattern rather than performing continuous or random adjustments.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively avoids resonance and ensures desired rotational speeds in a cost-effective manner by alternately adjusting advance and delay angles or performing overlap energization, reducing electromagnetic vibration and noise within a predetermined rotational speed range.
Implementation Method 1
reduce resonance between a natural frequency of the motor and a rotational component of the motor
Implementation Method 2
a motor driving unit for applying a voltage to each phase of a motor to drive the motor
Data Source
AI summary
A motor driving control device includes a motor driving unit to drive the motor, a rotational position detecting circuit for generating rotational position information, and a controller. The controller outputs, to the motor driving unit, a first drive control signal for controlling an adjustment at a time of energization switching to reduce resonance between a natural frequency of the motor and a rotational component of the motor based on the rotational position information when an actual rotational speed of the motor is equal to or higher than a predetermined rotational speed lower than a target rotational speed, and outputs, to the driving unit, a second drive control signal for controlling regular energization switching without performing the adjustment at the time of energization switching when the actual rotational speed is less than the predetermined rotational speed and a set duty is within an error range of a maximum value.