Draught Fan Air Volume Control Using Power and Speed Without Sensors
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Solution Overview
Problem
Existing draught fan technologies rely on anemometers or static pressure sensors for constant air volume control, which are costly and prone to malfunctions, and lack real-time dynamic adjustment capabilities.
Innovation Solution
A method for controlling a draught fan that adjusts air volume dynamically without anemometers or static pressure sensors, using actual rotating speed, power, and target air volume to calculate control duration and rotating speed step size for precise adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If anemometer or static pressure sensor is mounted for constant air volume control, then control accuracy is improved, but device cost and complexity increase
Solution Approach 1:
The patent extracts the air volume measurement function from external sensors (anemometer or static pressure sensor) and implements it through calculation based on power and rotating speed data that are already available from the draught fan's motor control system. This eliminates the need for additional sensing hardware while maintaining control accuracy.
Solution Approach 2:
The draught fan control system uses its own operational parameters (power consumption and rotating speed) to calculate and control air volume, rather than relying on external sensing devices. The system serves its own measurement needs through internal data processing.
2Measurement precision
If anemometer or static pressure sensor is mounted for constant air volume control, then control accuracy is improved, but device cost increases
Solution Approach 1:
The patent replaces expensive, fragile sensing hardware with a software-based calculation approach that uses existing motor control data. This significantly reduces manufacturing costs while maintaining the ability to achieve constant air volume control.
3Ease of manufacture
If conventional control method without sensors is used, then device cost is reduced, but real-time dynamic adjustment capability is lost
Solution Approach 1:
The patent implements a closed-loop feedback control system that continuously monitors power consumption and rotating speed, calculates actual air volume, compares it with target air volume, and adjusts motor output in real-time. This enables dynamic adjustment capability without requiring external sensors.
Solution Approach 2:
The system pre-establishes the relationship between motor parameters (power, speed) and air volume output, allowing it to predict and adjust air volume in real-time based on motor state without waiting for external sensor feedback.
4Ease of manufacture
If conventional control method without sensors is used, then device cost is reduced, but control accuracy deteriorates
Solution Approach 1:
The patent replaces mechanical sensing systems with an electrical/software-based calculation system that derives air volume from power and speed measurements. This substitution maintains or improves accuracy while reducing hardware complexity and cost.
Data Source
AI summary
A method and for controlling a draught fan including: obtaining an actual rotating speed, an actual power, and a target air volume of the draught fan, obtaining a target power corresponding to the target air volume according to the actual rotating speed and the target air volume, obtaining, in response to a power difference value between the actual power and the target power being not within an initial difference value range, a control duration and a rotating speed step size corresponding to the power difference value, and adjusting the actual rotating speed according to the rotating speed step size after the control duration. A dynamic adjustment of the air volume of the draught fan is achieved, and a constant air volume control of the draught fan with low cost, high control accuracy, fast adjustment speed and good stability is achieved.