Method for controlling air volume output

Abstract

A method for controlling air volume including: 1) establishing a functional relation formula for air volume in a microprocessor control unit of a motor controller; 2) inputting a target air volume into the microprocessor control unit of the motor controller; 3) starting a motor by the motor controller under a torque to enable the motor to fall on a steady state; 4) recording the rotational speed in the steady state, and calculating an air volume in the steady state; 5) comparing the target air volume with the calculated air volume; 6) re-recording a steady rotational speed after the motor falls on a new steady state under an increased or reduced torque, and recalculating the air volume in the new steady state; and 7) repeating steps 5) and 6) to adjust the torque until the calculated air volume is equal or equivalent to the target air volume.

The invention claimed is: 
     
         1 . A method for controlling air volume provided by a motor, the method comprising:
 1) testing a relationship between air volume and rotational speed of a motor system under multiple constant torques, and establishing a functional relation formula Q=F (T, n, V) for the air volume, Q representing the air volume, T representing a torque, n representing the rotational speed, V representing an adjustment coefficient, and each torque section having a corresponding adjustment coefficient which is input to a microprocessor control unit of a motor controller;   2) inputting a target air volume Q ref  into the microprocessor control unit of the motor controller;   3) starting the motor by the motor controller under the torque T to enable the motor to fall on a steady state;   4) recording the rotational speed in the steady state, acquiring the adjustment coefficient V under the torque T through a table look-up method, and calculating an air volume Q c  in the steady state according to the functional relation formula in step 1);   5) comparing the target air volume Q ref  with the calculated air volume Q c  by the microprocessor control unit of the motor controller, and a) maintaining the torque to work at the steady state and recording the rotational speed n if the target air volume Q ref  is equal or equivalent to the calculated air volume Q c ; or b) increasing the torque T through the motor controller if the target air volume Q ref  is greater than the calculated air volume Q c , or c) decreasing the torque T through the microprocessor control unit of the motor controller if the target air volume Q ref  is smaller than the calculated air volume Q c ;   6) re-recording a steady rotational speed after the motor falls on a new steady state under an increased or reduced torque, re-searching the corresponding adjustment coefficient V through the table look-up method, and recalculating the air volume Q c  in the new steady state; and   7) repeating step 5) and step 6) to adjust the torque until the calculated air volume Q is equal or equivalent to the target air volume Q ref , and recording the rotational speed n in the steady state after the motor falls on the steady state.   
     
     
         2 . The method of  claim 1 , wherein if the rotational speed and the output air volume change due to the alteration of an external system, the motor controller compares the new steady rotational speed with the rotational speed in step 5) or step 7) to acquire the change of output air volume, and then steps 4), 5), 6), and 7) are repeated. 
     
     
         3 . The method of  claim 1 , wherein a calculation formula for calculating air volume is as follows: 
       
         
           
             
               
                 Q 
                 = 
                 
                   
                     c 
                      
                     
                         
                     
                      
                     0 
                     × 
                     
                       
                         
                           T 
                           × 
                           V 
                         
                         
                           T 
                           base 
                         
                       
                     
                   
                   + 
                   
                     c 
                      
                     
                         
                     
                      
                     1 
                     × 
                     n 
                   
                 
               
               , 
               
                 
 
               
                
               or 
             
           
         
         
           
             
               
                 Q 
                 = 
                 
                   
                     c 
                      
                     
                         
                     
                      
                     0 
                     × 
                     
                       
                         
                           T 
                           × 
                           V 
                         
                         
                           T 
                           base 
                         
                       
                     
                   
                   + 
                   
                     c 
                      
                     
                         
                     
                      
                     1 
                     × 
                     n 
                   
                   + 
                   
                     c 
                      
                     
                         
                     
                      
                     2 
                     × 
                     
                       n 
                       2 
                     
                     × 
                     
                       
                         
                           T 
                           base 
                         
                         
                           T 
                           × 
                           V 
                         
                       
                     
                   
                 
               
               , 
             
           
         
       
       in which coefficients c0, c1, and c2 are obtained by a curve fitting method under different external static pressure conditions of a base torque T base  according to original data of the rotational speed and air volume parameters. 
     
     
         4 . The method of  claim 3 , wherein the base torque T base  ranges from 30% T 0  to 80% T 0 , and T 0  represents a rated torque of the motor. 
     
     
         5 . The method of  claim 1 , wherein the value of the adjustment coefficient V in the functional relation formula Q=F (T, n, V) ranges from 0.1 to 2. 
     
     
         6 . The method of  claim 3 , wherein the value of the adjustment coefficient V in the functional relation formula Q=F (T, n, V) ranges from 0.1 to 2. 
     
     
         7 . The method of  claim 1 , wherein the calculated air volume Q c  is equal or equivalent to the target air volume Q ref  in step 5) and step 7) means that the calculated air volume Q c  is in the range of “target air volume Q ref , ±error window”, and the error window of the target air volume Q ref  ranges from 1% to 2%. 
     
     
         8 . The method of  claim 3 , wherein the calculated air volume Q c  is equal or equivalent to the target air volume Q ref  in step 5) and step 7) means that the calculated air volume Q c  is in the range of “target air volume Q ref , ±error window”, and the error window of the target air volume Q ref  ranges from 1% to 2%. 
     
     
         9 . The method of  claim 1 , wherein increasing or decreasing the torque T through the motor controller in step 5) means increasing or decreasing the torque T according to step length sequence of at least 1% T 0  each time, or new torque=current torque×(target air volume Q ref /current calculated air volume Q c ) 2 . 
     
     
         10 . The method of  claim 3 , wherein increasing or decreasing the torque T through the motor controller in step 5) means increasing or decreasing the torque T according to step length sequence of at least 1% T 0  each time, or new torque=current torque×(target air volume Q ref /current calculated air volume Q c ) 2 . 
     
     
         11 . The method of  claim 1 , wherein the functional relation formula Q=F (T, n, V) is acquired as follows according to original data of rotational speed and air volume parameters under a base torque T base  and other torques and under different external static pressure:
 a) arranging the motor fixed on a wind wheel in an air-conditioning device;   b) setting the motor to work at the working state of constant torque;   c) selecting a plurality of torque values comprising the base torque within the range without exceeding a rated torque;   d) allowing the motor to work under different torques; and   e) changing the external static pressure of the system in sequence to collect the original data comprising the rotational speed and the air volume parameters.   
     
     
         12 . A method for controlling air volume provided by an air-conditioning fan system, the air-conditioning fan system comprising a wind wheel and a motor, the motor comprising a motor controller, a stator component, and a rotor component, the method comprising the following steps:
 1) setting the motor to work at a constant torque state, selecting a plurality of torque values comprising a base torque within a range without exceeding a rated torque, allowing the motor to work under different torques, and changing the external static pressure of the system in sequence to collect original data comprising rotational speed and air volume parameters;   2) establishing a functional relation formula Q=F (T, n, V) for the air volume, Q representing the air volume, T representing a torque, n representing the rotational speed, V representing an adjustment coefficient, and each torque section having a corresponding adjustment coefficient which is input to a microprocessor control unit of a motor controller;   3) inputting a target air volume Q ref  into the microprocessor control unit of the motor controller;   4) starting the motor by the motor controller under the torque T to enable the motor to fall on a steady state;   5) recording the rotational speed in the steady state, acquiring the adjustment coefficient V under the torque T through a table look-up method, and calculating an air volume Q c  in the steady state according to the functional relation formula in step 1);   6) comparing the target air volume Q ref  with the calculated air volume Q c  by the microprocessor control unit of the motor controller, and a) maintaining the torque to work at the steady state and recording the rotational speed n if the target air volume Q ref  is equal or equivalent to the calculated air volume Q c ; or b) increasing the torque T through the motor controller if the target air volume Q ref  is greater than the calculated air volume Q c , or c) decreasing the torque T through the microprocessor control unit of the motor controller if the target air volume Q ref  is smaller than the calculated air volume Q c ;   7) re-recording a steady rotational speed after the motor falls on a new steady state under an increased or reduced torque, re-searching the corresponding adjustment coefficient V by the motor controller through the table look-up method, and recalculating the air volume Q c  in the new steady state; and   8) repeating step 6) and step 7) to adjust the torque until the calculated air volume Q c  is equal or equivalent to the target air volume Q ref , and recording the rotational speed n in the steady state after the motor falls on the steady state.   
     
     
         13 . The method of  claim 12 , wherein if the rotational speed and the output air volume change due to the alteration of an external system, the motor controller compares the new steady rotational speed with the rotational speed in step 6) or step 8) to acquire the change of output air volume, and then steps 5), 6), 7), and 8) are repeated. 
     
     
         14 . The method of  claim 12 , wherein a calculation formula for calculating air volume is as follows: 
       
         
           
             
               
                 Q 
                 = 
                 
                   
                     c 
                      
                     
                         
                     
                      
                     0 
                     × 
                     
                       
                         
                           T 
                           × 
                           V 
                         
                         
                           T 
                           base 
                         
                       
                     
                   
                   + 
                   
                     c 
                      
                     
                         
                     
                      
                     1 
                     × 
                     n 
                   
                 
               
               , 
               
                 
 
               
                
               or 
             
           
         
         
           
             
               
                 Q 
                 = 
                 
                   
                     c 
                      
                     
                         
                     
                      
                     0 
                     × 
                     
                       
                         
                           T 
                           × 
                           V 
                         
                         
                           T 
                           base 
                         
                       
                     
                   
                   + 
                   
                     c 
                      
                     
                         
                     
                      
                     1 
                     × 
                     n 
                   
                   + 
                   
                     c 
                      
                     
                         
                     
                      
                     2 
                     × 
                     
                       n 
                       2 
                     
                     × 
                     
                       
                         
                           T 
                           base 
                         
                         
                           T 
                           × 
                           V 
                         
                       
                     
                   
                 
               
               , 
             
           
         
       
       in which coefficients c0, c1, and c2 are obtained by a curve fitting method under different external static pressure conditions of base torque T base  according to the original data of the rotational speed and air volume parameters. 
     
     
         15 . The method of  claim 14 , wherein the base torque T base  ranges from 30% T 0  to 80% T 0 , and T 0  represents a rated torque of the motor. 
     
     
         16 . The method of  claim 12 , wherein the value of the adjustment coefficient V in the functional relation formula Q=F (T, n, V) ranges from 0.1 to 2. 
     
     
         17 . The method of  claim 14 , wherein the value of the adjustment coefficient V in the functional relation formula Q=F (T, n, V) ranges from 0.1 to 2. 
     
     
         18 . The method of  claim 12 , wherein the calculated air volume Q c  is equal or equivalent to the target air volume Q ref  in step 6) and step 8) means that the calculated air volume Q c  is in the range of “target air volume Q ref , ±error window”, and the error window of the target air volume Q ref  ranges from 1% to 2%. 
     
     
         19 . The method of  claim 14 , wherein the calculated air volume Q c  is equal or equivalent to the target air volume Q ref  in step 6) and step 8) means that the calculated air volume Q is in the range of “target air volume Q ref , ±error window”, and the error window of the target air volume Q ref  ranges from 1% to 2%. 
     
     
         20 . The method of  claim 12 , wherein increasing or decreasing the torque T through the motor controller in step 6) means increasing or decreasing the torque T according to step length sequence of at least 1% T 0  each time, or new torque=current torque×(target air volume Q ref /current calculated air volume Q) 2 .