Direct power control for constant airflow control
AssigneeZhongshan Broad-Ocean Motor Co., Ltd.
InventorsZheng Zhang, Jizhong Wang, Yiqiao Zhou, Yong Zhao
Life of this patent
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Abstract
A control method for constant airflow controlled by a direct power-controlled PM motor, wherein the PM motor is installed in an HVAC system to drive the rotation of a fan wheel, and wherein the PM motor has a stator component, permanent magnet rotor components, and a motor controller. In some embodiments, the motor controller includes an operation parameters sensing circuit and a microprocessor.
Claims18
A method for providing constant airflow with a variable speed motor in a Heating, Ventilation, and Air Conditioning (HVAC) system, comprising:
- (a) determining a power and speed of the motor to obtain a motor control working point of the motor, wherein the motor control working point specifies the power and speed of the motor;
- (b) obtaining a target airflow rate for the HVAC system;
- and
- (c) determining a target airflow working point of the motor that yields the target airflow rate in the HVAC system, wherein the target airflow working point is determined based, at least in part, on the obtained target airflow rate for the HVAC system, and wherein the target airflow working point specifies the power and speed of the motor that yields the target airflow rate in the HVAC system;
- (d) determining whether the motor control working point is approximately equal to the target airflow working point of the motor;
- and
- (e) successively adjusting the power and speed of the motor when the motor control working point is not approximately equal to the target airflow working point, wherein successively adjusting the power and speed of the motor comprises adjusting the motor power and then subsequently adjusting the motor speed, and wherein the motor power and speed are successively adjusted until the motor control working point of the motor is approximately equal to the target airflow working point such that airflow provided by the HVAC system is maintained constant at the target airflow rate before and after the step of successively adjusting the power and speed of the motor.
An apparatus for providing constant airflow in a Heating, Ventilation, and Air Conditioning (HVAC) system, comprising:
- a variable speed motor;
- and
- a motor controller coupled to the variable speed motor and configured to control the operation of the variable speed motor, the motor controller comprising a processor configured to perform the steps of:
- (a) determining a power and speed of the motor to obtain a motor control working point of the motor, wherein the motor control working point specifies the power and speed of the motor;
- (b) obtaining a target airflow rate for the HVAC system;
- (c) determining a target airflow working point of the motor that yields the target airflow rate in the HVAC system, wherein the target airflow working point is determined based, at least in part, on the obtained target airflow rate for the HVAC system, and wherein the target airflow working point specifies the power and speed of the motor that yields the target airflow rate in the HVAC system;
- (d) determining whether the motor control working point is approximately equal to the target airflow working point of the motor;
- and
- (e) successively adjusting the power and speed of the motor when the motor control working point is not approximately equal to the target airflow working point, wherein successively adjusting the power and speed of the motor comprises adjusting the motor power and then subsequently adjusting the motor speed, and wherein the motor power and speed are successively adjusted until the motor control working point of the motor is approximately equal to the target airflow working point such that airflow provided by the HVAC system is maintained constant at the target airflow rate before and after the step of successively adjusting the power and speed of the motor.
Dependencies are inferred from the claim text.