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; 3) starting a motor by the motor controller to enable the motor to achieve a rotational speed and fall on a steady state; 4) recording the torque and 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 torque after the motor falls on a new steady state under an increased or reduced rotational speed, and recalculating the air volume in the new steady state; and 7) repeating steps 5) and 6) to adjust the rotational speed 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 torque of a motor system under multiple constant rotational speed values, and establishing a functional relation formula Q=F (T, n, V) for the air volume, Q representing the air volume, T representing the torque, n representing a rotational speed, V representing an adjustment coefficient, and each rotational speed 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 to enable the motor to achieve the rotational speed and fall on a steady state;   4) recording the torque and the rotational speed n in the steady state, acquiring the adjustment coefficient V under the rotational speed n 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 rotational speed to work at the steady state and recording the torque T if the target air volume Q ref  is equal or equivalent to the calculated air volume Q c ; or b) increasing the rotational speed n through the motor controller if the target air volume Q ref  is greater than the calculated air volume Q c , or c) decreasing the rotational speed n 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 torque T after the motor falls on a new steady state under an increased or reduced rotational speed, 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   7) repeating step 5) and step 6) to adjust the rotational speed until the calculated air volume Q c  is equal or equivalent to the target air volume Q ref , and recording the torque T in the steady state after the motor falls on the steady state.   
     
     
         2 . The method of  claim 1 , wherein if the torque and output air volume change due to the alteration of an external system, the motor controller compares the new steady torque with the torque 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 the air volume is as follows: 
       
         
           
             
               
                 Q 
                 = 
                 
                   
                     c 
                      
                     
                         
                     
                      
                     0 
                     × 
                     
                       
                         n 
                         × 
                         V 
                       
                       
                         n 
                         base 
                       
                     
                   
                   + 
                   
                     c 
                      
                     
                         
                     
                      
                     1 
                     × 
                     T 
                     × 
                     
                       
                         n 
                         base 
                       
                       
                         n 
                         × 
                         V 
                       
                     
                   
                 
               
               , 
               
                 
 
               
                
               or 
             
           
         
         
           
             
               
                 Q 
                 = 
                 
                   
                     c 
                      
                     
                         
                     
                      
                     0 
                     × 
                     
                       
                         n 
                         × 
                         V 
                       
                       
                         n 
                         base 
                       
                     
                   
                   + 
                   
                     c 
                      
                     
                         
                     
                      
                     1 
                     × 
                     T 
                     × 
                     
                       
                         n 
                         base 
                       
                       
                         n 
                         × 
                         V 
                       
                     
                   
                   + 
                   
                     c 
                      
                     
                         
                     
                      
                     2 
                     × 
                     
                       T 
                       2 
                     
                     × 
                     
                       
                         ( 
                         
                           
                             n 
                             base 
                           
                           
                             n 
                             × 
                             V 
                           
                         
                         ) 
                       
                       3 
                     
                   
                 
               
               , 
             
           
         
       
       in which coefficients c0, c1, and c2 are obtained by a curve fitting method under different external static pressure conditions of base rotational speed n base  according to the original data of the torque and air volume parameters. 
     
     
         4 . The method of  claim 3 , wherein the base rotational speed n base  ranges from 30% n max  to 80% n max , and n max  represents a maximal rotational speed 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 rotational speed n through the motor controller in step 5) means increasing or decreasing the rotational speed n according to step length sequence of at least 1% n max  each time, or new rotational speed=current rotational speed×(target air volume Q ref /current calculated air volume Q c ) 2 . 
     
     
         10 . The method of  claim 3 , wherein increasing or decreasing the rotational speed n through the motor controller in step 5) means increasing or decreasing the rotational speed n according to step length sequence of at least 1% n max  each time, or new rotational speed=current rotational speed×(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 torque and air volume parameters under a base rotational speed n base  and other rotational speed values 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 rotational speed;   c) selecting a plurality of rotational speed values comprising the base rotational speed within the range without exceeding the maximal rotational speed;   d) allowing the motor to work under different rotational speed values; and   e) changing the external static pressure of the system in sequence to collect the original data comprising the torque 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, and the method comprising the following steps:
 1) setting the motor to work at a constant rotational speed state, selecting a plurality of rotational speed values comprising a base rotational speed within a range without exceeding the maximal rotational speed, allowing the motor to work under different rotational speed values, and changing the external static pressure of the system in sequence to collect the original data comprising torque 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 the torque, n representing the rotational speed, V representing an adjustment coefficient, and each rotational speed section having a corresponding adjustment coefficient which is input to a microprocessor control unit of the 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 to enable the motor to achieve a rotational speed and fall on a steady state;   5) recording the torque T and the rotational speed n in the steady state, acquiring the adjustment coefficient V under the rotational speed n 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 rotational speed to work at the steady state and recording the torque T if the target air volume Q ref  is equal or equivalent to the calculated air volume Q c ; or b) increasing the rotational speed n through the motor controller if the target air volume Q ref  is greater than the calculated air volume Q c , or c) decreasing the rotational speed n 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 torque after the motor falls on a new steady state under an increased or reduced rotational speed, 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 rotational speed until the calculated air volume Q c  is equal or equivalent to the target air volume Q ref , and recording the torque T in the steady state after the motor falls on the steady state.   
     
     
         13 . The method of  claim 12 , wherein if the torque and the output air volume change due to the alteration of an external system, the motor controller compares the new steady torque with the torque 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 
                     × 
                     
                       
                         n 
                         × 
                         V 
                       
                       
                         n 
                         base 
                       
                     
                   
                   + 
                   
                     c 
                      
                     
                         
                     
                      
                     1 
                     × 
                     T 
                     × 
                     
                       
                         n 
                         base 
                       
                       
                         n 
                         × 
                         V 
                       
                     
                   
                 
               
               , 
               
                 
 
               
                
               or 
             
           
         
         
           
             
               
                 Q 
                 = 
                 
                   
                     c 
                      
                     
                         
                     
                      
                     0 
                     × 
                     
                       
                         n 
                         × 
                         V 
                       
                       
                         n 
                         base 
                       
                     
                   
                   + 
                   
                     c 
                      
                     
                         
                     
                      
                     1 
                     × 
                     T 
                     × 
                     
                       
                         n 
                         base 
                       
                       
                         n 
                         × 
                         V 
                       
                     
                   
                   + 
                   
                     c 
                      
                     
                         
                     
                      
                     2 
                     × 
                     
                       T 
                       2 
                     
                     × 
                     
                       
                         ( 
                         
                           
                             n 
                             base 
                           
                           
                             n 
                             × 
                             V 
                           
                         
                         ) 
                       
                       3 
                     
                   
                 
               
               , 
             
           
         
       
       in which coefficients c0, c1, and c2 are obtained by a curve fitting method under different external static pressure conditions of base rotational speed n base  according to the original data of the torque and air volume parameters. 
     
     
         15 . The method of  claim 14 , wherein the base rotational speed n base  ranges from 30% n max  to 80% n max , and n max  represents a maximal rotational speed 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 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%. 
     
     
         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 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%. 
     
     
         20 . The method of  claim 12 , wherein increasing or decreasing the rotational speed n through the motor controller in step 6) means increasing or decreasing the rotational speed n according to step length sequence of at least 1% n max  each time, or new rotational speed=current rotational speed ×(target air volume Q ref /current calculated air volume Q c ) 2 .