Drive control method and drive system operating according to said method
AssigneeSiemens Aktiengesellschaft
InventorAndreas Kube
Life of this patent
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Abstract
A method for drive control of a vertical mill having a grinding plate rotatable about the vertical axis by a drive train composed of an electric motor and a gearbox is disclosed. At least the electric motor and the grinding plate represent inertia elements in a system that can oscillate and are connected by the gearbox operating as a torsion spring element. A variation in the rotation speed of at least one of the inertia elements is measured, and the electric motor is governed by a controller that minimizes the measured variation in the rotation speed. The controller is parameterized for governing the electric motor so as to minimize maximum reaction torques resulting in the gearbox when applying a sinusoidal excitation.
Claims14
A method of controlling a drive system for a vertical mill having a grinding plate driven by an electric motor and a drive train comprising a gearbox for rotation about a vertical axis, with the electric motor and the grinding plate representing mass inertia elements in an oscillating system which are connected by the gearbox operating as a torsion spring element, the method comprising:
- measuring a rotational speed variation of at least one of the mass inertia elements;
- governing the electric motor by way of a controller to minimize the measured rotational speed variation;
- parameterizing the controller for governing the electric motor with at least one adjustable controller parameter which is selected to minimize maximum reaction torques resulting in the gearbox when a sinusoidal excitation is imparted on the drive train by the grinding plate;
- experimentally determining on the vertical mill or determining from a simulation of the vertical mill a plurality of degrees of damping as a function of the at least one adjustable controller parameter,
- determining an extreme value by performing an extreme value search in the plurality of degrees of damping, and
- applying to the controller the at least one controller parameter based on the determined extreme value.
A drive system for a vertical mill having a grinding plate rotatable about a vertical axis, the drive system comprising:
- an electric motor driving the grinding plate,
- a drive train comprising at least one gearbox, and
- a control device for drive control of the vertical mill, wherein the control device comprises
- a controller configured to execute program instructions which are stored on a non-transitory storage medium and which, when loaded into a memory of the controller, cause the control device to
- measure a rotational speed variation of the electric motor or the grinding plate;
- govern the electric motor by way of a controller to minimize the measured rotational speed variation;
- parameterize the controller for governing the electric motor with at least one adjustable controller parameter which is selected to minimize maximum reaction torques resulting in the gearbox when a sinusoidal excitation is imparted on the drive train by the grinding plate,
- experimentally determine on the vertical mill or determine from a simulation of the vertical mill a plurality of degrees of damping as a function of the at least one adjustable controller parameter,
- determine an extreme value by performing an extreme value search in the plurality of degrees of damping, and
- apply to the controller the at least one controller parameter based on the determined extreme value.
A vertical mill, comprising:
- a grinding plate driven by an electric motor and a drive train comprising at least one gearbox for rotation about a vertical axis,
- a drive system comprising a control device for drive control of the vertical mill, wherein the control device comprises
- a controller configured to execute program instructions which are stored on a non-transitory storage medium and which, when loaded into a memory of the controller, cause the control device to
- measure a rotational speed variation of the electric motor or the grinding plate;
- govern the electric motor by way of a controller to minimize the measured rotational speed variation;
- parameterize the controller for governing the electric motor with at least B one adjustable controller parameter which is selected to minimize maximum reaction torques resulting in the gearbox when a sinusoidal excitation is imparted on the drive train by the grinding plate,
- experimentally determine on the vertical mill or determine from a simulation of the vertical mill a plurality of degrees of damping as a function of the at least one adjustable controller parameter,
- determine an extreme value by performing an extreme value search in the plurality of degrees of damping, and
- apply to the controller the at least one controller parameter based on the determined extreme value.
Dependencies are inferred from the claim text.