Motor controller for electric blowers
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Solution Overview
Problem
Existing motor controllers struggle to maintain constant airflow production in HVAC systems using backward-curved electric blowers, as they produce multiple airflow values at given torque and speed, especially at high airflow values, making it difficult to operate effectively in torque-control or speed-control modes.
Innovation Solution
A motor controller with a processor that computes system resistance and adjusts electrical power supply to the blower motor, using airflow algorithms that correlate torque, speed, and system resistance to maintain constant airflow, allowing operation in both torque and speed control modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If backward-curved blowers are used to improve efficiency and reduce power consumption, then energy efficiency is improved, but the blowers produce multiple different airflows at given torque and speed making control difficult
Solution Approach 1:
The patent applies parameter changes by transitioning from traditional torque-control or speed-control modes to a system resistance-control mode. The motor controller computes system resistance based on monitored motor speed and torque, then uses this computed resistance value to determine the appropriate operating parameters. This parameter transformation resolves the control difficulty by creating a unique correspondence between system resistance and airflow, eliminating the multiple airflow values problem inherent in backward-curved blowers when operated in conventional control modes
2Ease of operation
If traditional torque-control or speed-control modes are used, then control is straightforward, but constant airflow production cannot be achieved with backward-curved blowers
Solution Approach 1:
The patent implements feedback control by continuously monitoring motor speed and torque, computing system resistance from these measurements, and using the computed resistance to adjust control parameters. This closed-loop feedback mechanism ensures constant airflow production by dynamically adapting to changing system conditions while maintaining straightforward control through automated computation and adjustment
Solution Approach 2:
The patent applies preliminary action by pre-computing the system resistance value based on monitored parameters before adjusting control settings. The controller calculates the appropriate operating point in advance using the computed resistance, then implements the control adjustment, ensuring constant airflow is achieved proactively rather than reactively
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
Enables efficient and accurate constant airflow production in HVAC systems using backward-curved blowers, improving efficiency and pressure generation while maintaining benefits over radial or forward-curved blowers, and reducing blower size and power consumption.
Implementation Method 1
The drive circuit is configured to regulate electrical power supplied to a stator of the electric motor to turn a rotor of the electric motor and generate the airflow
Data Source
AI summary
A motor controller for an electric motor for driving a blower to generate an airflow. The motor controller includes a processor and a drive circuit configured to regulate power supplied to the motor to turn the blower. The processor computes a system resistance for the blower based on a fixed set point for a first control parameter and a feedback parameter. The processor receives an airflow rate demand value and computes an operating set point for a second control parameter based on the system resistance and the airflow rate demand value. The processor controls the drive circuit based on the operating set point to supply electrical power to the electric motor and to operate the blower to generate the airflow.