Drive arrangement with collectorless d.c. motor

Abstract

Drive arrangement comprising a collectorless d.c. motor and a rpm-regulating arrangement. The motor comprises a permanent-magnet rotor and a stator winding arrangement. The latter is connected to a current source in dependence upon angular-position signals by means of an electrical commutation arrangement. The rpm-regulating arrangement produces a regulator signal that is a function of the deviation of the rotor's actual rpm from a desired rpm. There is provided an arrangement for modulating the regulator signal in synchronism with the rotation of the rotor. As a result of the action of the modulation arrangement, the current flowing in the stator winding arrangement between each two successive commutation operations initially builds up beginning at a point in time at least approximately coinciding with the point in time at which the commutation occurs, and the drops off again until a point in time at least approximately coinciding with the point in time at which the next-following commutation occurs.

I claim: 
     
       1. Drive arrangement having a collectorless d.c. motor comprising a permanent-magnet rotor and a stator winding arrangement; an angular-position transducer arrangement which during operation furnishes angular-position signals that are a function of the angular position of the rotor; an electrical commutation arrangement which receives the angular-position signals and selectively connects the stator winding arrangement to a current source; an rpm-measuring arrangement for generating an actual-rpm signal corresponding to the rotor's actual rpm; a desired-value signal generator for furnishing a signal corresponding to the desired rotor rpm; an rpm-regulating arrangement having respective inputs for the actual-rpm signal and desired-rpm signal and an output, for generating a regulator signal that appears at the output of the rpm-regulating arrangement and is a function of the deviation of the actual rpm from the desired rpm of the rotor, and which controls the supply of current to the stator winding arrangement; and an arrangement for modulating the regulator signal .Iadd.by superimposing a modulating signal separate from the actual rpm signal and the desired rpm signal and .Iaddend.in synchronism with the rotor's rotation, in such a fashion that the current flowing in the stator winding arrangement between each two successive commutation operations initially builds up beginning at a point in time at least approximately coinciding with the point in time at which the commutation occurs, and then drops off again until a point in time at least approximately coinciding with the point in time at which the next-following commutation occurs. 
     
     
       2. Drive arrangement . .according to claim 1.!. .Iadd.having a collectorless d.c. motor comprising a permanent-magnet rotor and a stator winding arrangement; an angular-position transducer arrangement which during operation furnishes angular-position signals that are a function of the angular position of the rotor; and electrical commutation arrangement which receives the angular-position signals and selectively connects the stator winding arrangement to a current source; and rpm-measuring arrangement for generating an actual-rpm signal corresponding to the rotor's actual rpm; a desired-value signal generator for furnishing a signal corresponding to the desired rotor rpm; and rpm-regulating arrangement having respective inputs for the actual-rpm signal and desired-rpm signal and an output, for generating a regulator signal that appears at the output of the rpm-regulating arrangement and is a function of the deviation of the actual rpm from the desired rpm of the rotor, and which controls to the supply of current to the stator winding arrangement; and an arrangement for modulating the regulator signal in synchronism with the rotor's rotation, in such a fashion that the current flowing in the stator winding arrangement between each two successive commutation operations initially builds up beginning at a point in time at least approximately coinciding with the point in time at which the commutation occurs and then drops off again until a point in time at least approximately coinciding with the point in time at which the next-following commutation occurs.Iaddend., the modulation arrangement being so designed that, superimposed upon the regulator signal that represents a function of the deviation of the actual rpm from the desired rpm, there is a signal corresponding at least approximately to a rectified sinusoid whose points of inflection coincide with the points in time at which commutation occurs. 
     
     
       3. Drive arrangement according to claim 1, the modulation arrangement producing a modulation signal that is superimposed upon the actual-rpm signal. 
     
     
       4. Drive arrangement according to claim 1, the modulation arrangement producing a modulation signal that is superimposed upon the desired-rpm signal. 
     
     
       5. Drive arrangement according to claim 1, the modulation arrangement producing a modulation signal which is superimposed upon the regulator signal that represents a function of the deviation of the actual rpm from the desired rpm of the rotor. 
     
     
       6. Drive arrangement . .according to claim 1.!. .Iadd.having a collectorless d.c. motor comprising a permanent-magnet rotor and a stator winding arrangement; an angular-position transducer arrangement which during operation furnishes angular-position signals that are a function of the angular position of the rotor; an electrical commutation arrangement which receives the angular-position signals and selectively connects the stator winding arrangement to a current source; an rpm-measuring arrangement for generating an actual-rpm signal corresponding to the rotor's actual rpm; a desired-value signal generator for furnishing a signal corresponding to the desired rotor rpm; and rpm-regulating arrangement having respective inputs for the actual-rpm signal and desired-rpm signal and an output, for generating a regulator signal that appears at the output of the rpm-regulating arrangement and is a function of the deviation of the actual rpm from the desired rpm of the rotor, and which controls the supply of current to the stator winding arrangement; and an arrangement for modulating the regulator signal in synchronism with the rotor's rotation, in such a fashion that the current flowing the stator winding arrangement between each two successive commutation operations initially builds up beginning at a point in time at least approximately coinciding with the point in time at which the commutation occurs and then drops off again until a point in time at least approximately coinciding with the point in time at which the next-following commutation occurs.Iaddend., the stator winding arrangement being provided with means for coupling out the voltages that are induced in the windings of the stator winding arrangement and form . .the.!. .Iadd.a .Iaddend.modulation signal. 
     
     
       7. Drive arrangement according to claim 6, the modulation arrangement comprising a filter arrangement for shaping the modulation signal into a wave shape approximating to a rectified sinusoid voltage. .Iadd. 
     
     
       8.  Drive arrangement having a collectorless d.c. motor comprising a permanent-magnet rotor and   a stator winding arrangement;   an angular-position transducer arrangement which during operation furnishes angular-position signals that are a function of the angular position of the rotor,   an electrical commutation arrangement which receives the angular-position signals and selectively connects the stator winding arrangement to a current source;   a motor-operation sensing arrangement for generating an actual-value signal having a value corresponding to a predetermined aspect of rotor rotation;   a desired-value signal generator for furnishing a desired-value signal corresponding to the desired value of said predetermined aspect of rotor rotation;   an rpm-regulating arrangement having input means for receipt of signals from which information can be derived concerning the deviation of said desired value from said actual value and having output means, and operative for generating a regulator signal which appears at said output means and which is a function of said deviation, and which controls the supply of current to the stator winding arrangement in a manner maintaining the rpm of said rotor at a predetermined value; and   an arrangement for modulating the regulator signal by superimposing a modulating signal separate from the actual-value signal and the desired-value signal and in synchronism with the rotor's rotation, in such a fashion that the current flowing in the stator winding arrangement between each two successive commutation operations initially builds up beginning at a point in time at least approximately coinciding with the point in time at which the commutation occurs, and then drops off again until a point in time at least approximately coinciding with the point in time at which the next-following commutation occurs. .Iaddend. .Iadd.   
     
     
       9.  Drive arrangement according to claim 8, the modulation arrangement producing a modulation signal corresponding at least approximately to a rectified sinusoid whose points of inflection coincide with the points in time at which commutation occurs. .Iaddend. .Iadd.10. Drive arrangement according to claim 8, the modulation arrangement producing a modulation signal that is superimposed upon the actual-value signal. .Iaddend. .Iadd.11. Drive arrangement according to claim 8, the modulation arrangement producing a modulation signal that is superimposed upon the desired-value signal. .Iaddend. .Iadd.12. Drive arrangement according to claim 8, the modulation arrangement producing a modulation signal that is superimposed upon the regulator signal which is a function of the deviation of said desired value from said actual value. .Iaddend. 
     
     
        .Iadd.     Drive arrangement according to claim 8, the stator winding arrangement being provided with means for coupling out voltages that are induced in windings of the stator winding arrangement and form the modulation signal. .Iaddend. .Iadd.14. Drive arrangement according to claim 13, the modulation arrangement comprising a filter arrangement for shaping the modulation signal into a wave shape approximating a rectified sinusoid voltage. .Iaddend.