Method, apparatus, and system for drive control, power conversion, and start-up control in an srm or pmbdcm drive system

Abstract

A power converter for a switched reluctance motor or a permanent magnet brushless direct current (dc) motor may include first and second partial circuits for forming multiple conduction circuits in cooperation with first and second phase windings of the motor. The controller also includes a switch operable to open and close a first conduction circuit, which includes the first phase winding, and to regulate energization of the first and second phase windings of the motor through opening and closing the first conduction circuit. Control of the switch provides four-quadrant operation of the motor through regulated energization of the first and second phase windings.

1 . A controller for a switched reluctance motor or a permanent magnet brushless direct current (dc) motor having first and second phase windings, the controller comprising: 
 first and second components that cooperate with the first and second phase windings of the motor to provide conduction circuits; and    a switch, connected to said first and second components, that closes and opens a first of the conduction circuits, which includes the first phase winding, so as to regulate, without the assistance of another switch, energization of the first and second phase windings of the motor and provide four-quadrant operation of the motor.    
   
   
       2 . The controller of  claim 1 , wherein said first and second components comprise: 
 a capacitor that stores energy received from the first phase winding after the switch opens the first conduction circuit; and    a rectifier that prevents current from flowing through the second phase winding to charge the capacitor.    
   
   
       3 . The controller of  claim 2 , wherein the capacitor provides stored energy to energize the second phase winding.  
   
   
       4 . The controller of  claim 1 , wherein said first and second components comprise: 
 a capacitor that stores energy for energizing the second phase winding, wherein the capacitor is charged by snubbing energy received from the first phase winding when the switch opens the first conduction circuit.    
   
   
       5 . The controller of  claim 1 , wherein said first and second components comprise: 
 a capacitor that stores energy for energizing the second phase winding; and    a rectifier that conducts current away from the first phase winding when the switch is opened, wherein:    a first terminal of the rectifier is connected to a first terminal of the switch,    a second terminal of the rectifier is connected to a first terminal of the capacitor, and    a second terminal of the capacitor is connected to a second terminal of the switch.    
   
   
       6 . The controller of  claim 1 , wherein said first and second components comprise: 
 a capacitor that stores energy for energizing the second phase winding; and    a rectifier that conducts energy away from the first phase winding to store in the capacitor, after the switch is opened.    
   
   
       7 . The controller of  claim 6 , wherein the rectifier prevents the capacitor from releasing the stored energy directly, through the flow of a current, to the main phase winding and the switch.  
   
   
       8 . The controller of  claim 1 , wherein said first and second components and the switch cooperate to start the motor from any static relative positioning of rotor and stator poles of the motor.  
   
   
       9 . The controller of  claim 1 , wherein the motor is a two-phase motor.  
   
   
       10 . The controller of  claim 1 , wherein said first and second components comprise: 
 a resistor for being in a series conduction path with the first phase winding, wherein a current through the first phase winding is determinable from a voltage developed across the resistor.    
   
   
       11 . The controller of  claim 1 , wherein said first and second components comprise: 
 a resistor for being in a series conduction path with the second phase winding, wherein a rotor position of the motor is determinable from a voltage developed across the resistor.    
   
   
       12 . The controller of  claim 1 , wherein said first component comprises a rectifier that rectifies an alternating current (ac) and provides the rectified current to the second component.  
   
   
       13 . The controller of  claim 12 , wherein said first component additionally comprises a capacitor that cooperates with the rectifier to provide a filtered dc voltage to the second component.  
   
   
       14 . The controller of  claim 1 , wherein said first and second components comprise a capacitor that stores energy for energizing the second phase winding.  
   
   
       15 . The controller of  claim 14 , wherein said first and second components further comprise a rectifier that prevents current from flowing through the second phase winding in one direction.  
   
   
       16 . The controller of  claim 1 , wherein said first and second components cooperate with the first and second phase windings, under the control of the switch, to provide a unity power factor.  
   
   
       17 . The controller of  claim 1 , wherein said first and second components cooperate with the first and second phase windings, under the control of the switch, to provide input alternating current shaping.  
   
   
       18 . A switched reluctance motor system, comprising: 
 a brushless dc motor that has first and second phase windings;    a first conduction circuit which includes the first phase winding; and    a switch that opens and closes said first conduction circuit to regulate, without the assistance of another switch, energization of the first and second phase windings of the motor and provide four-quadrant operation of the motor.    
   
   
       19 . A method of controlling a multi-phase direct current (dc) motor, the method comprising: 
 (a) energizing a main winding of the motor with a first current;    (b) discontinuing the energization of the main winding;    (c) determining, after discontinuing the energization of the main winding, whether a rotor of the motor is rotating; and    (d) energizing the main winding with a predetermined amount of current that differs from the first current, if the rotor is determined not to be rotating.    
   
   
       20 . The method of  claim 19 , wherein the predetermined amount of current is approximately  25  percent greater than the first current.  
   
   
       21 . The method of  claim 19 , further comprising repeating steps (b) and (c).  
   
   
       22 . The method of  claim 21 , further comprising repeating step (d).  
   
   
       23 . The method of  claim 22 , wherein the predetermined amount of current applied to the main winding during the third energization is approximately  50  percent greater than the first current.  
   
   
       24 . The method of  claim 19 , further comprising repeating steps (b), (c), and (d) until the rotor is determined to be rotating.  
   
   
       25 . The method of  claim 24 , wherein the predetermined amount of current applied to the main winding during the second and all subsequent energization cycles is a predetermined amount more than the current applied in the respective previous energization cycle.