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EP-4738692-A1 - A METHOD, AN ARRANGEMENT AND A FREQUENCY CONVERTER FOR CONTROLLING VIBRATION OF A SLEEVE BEARING VFD MOTOR

EP4738692A1EP 4738692 A1EP4738692 A1EP 4738692A1EP-4738692-A1

Abstract

The present invention relates to the field of electric drive devices and sleeve bearing VFD motors, such as electric motors and electric generators for industrial applications, and more particularly to a method, an arrangement and a frequency converter for controlling vibration of a sleeve bearing VFD motor. The arrangement of the present invention for controlling vibration of a sleeve bearing VFD motor comprises a frequency converter (11), one or more vibration sensors (17-18, 91) and a sleeve bearing VFD motor (12), said one or more vibration sensors (17-18, 91) comprising one or more vibration sensors (17-18, 91) of said sleeve bearing VFD motor (12), wherein said one or more vibration sensors (17-18, 91) is/are arranged for measuring at least horizontal vibration from said sleeve bearing VFD motor and for producing measured vibration data; and wherein said frequency converter (11) is arranged for generating a control torque and for exerting said control torque on the stator of said sleeve bearing VFD motor (12) for controlling vibration of said sleeve bearing VFD motor (12), said control torque being determined utilizing said measured vibration data.

Inventors

  • HOLOPAINEN, TIMO

Assignees

  • ABB SCHWEIZ AG

Dates

Publication Date
20260506
Application Date
20241104

Claims (15)

  1. A method for controlling vibration of a sleeve bearing VFD motor (12), in which method: - at least horizontal vibration from said sleeve bearing VFD motor is measured (21) by one or more vibration sensors (17-18, 91) as measured vibration data, said one or more vibration sensors (17-18, 91) comprising one or more vibration sensors (17-18, 91) of said sleeve bearing VFD motor (12); - control torque is determined (22) utilizing said measured vibration data; and - control torque is generated (23) by said frequency converter (11) and exerted on the stator of said sleeve bearing VFD motor (12) for controlling vibration of said sleeve bearing VFD motor (12).
  2. A method according to claim 1, wherein horizontal vibration and vertical vibration from said sleeve bearing VFD motor is measured (21) by one or more vibration sensors (17-18, 91) as measured vibration data.
  3. A method according to claim 1 or to claim 2, wherein in generating (23) said control torque: - a control torque reference is calculated by said frequency converter (11); and - control torque is generated (23) by said frequency converter (11) corresponding to said control torque reference.
  4. A method according to any of the claims 1-3, wherein said measured vibration data is utilized for suppression of vibration of said sleeve bearing VFD motor (12) at least at the low frequency critical speed frequency area/areas.
  5. An arrangement for controlling vibration of a sleeve bearing VFD motor, said arrangement comprising a frequency converter (11), one or more vibration sensors (17-18, 91) and a sleeve bearing VFD motor (12), said one or more vibration sensors (17-18, 91) comprising one or more vibration sensors (17-18, 91) of said sleeve bearing VFD motor (12), - wherein said one or more vibration sensors (17-18, 91) is/are arranged for measuring at least horizontal vibration from said sleeve bearing VFD motor and for producing measured vibration data; and - wherein said frequency converter (11) is arranged for generating a control torque and for exerting said control torque on the stator of said sleeve bearing VFD motor (12) for controlling vibration of said sleeve bearing VFD motor (12), said control torque being determined utilizing said measured vibration data.
  6. An arrangement according to claim 5, wherein said one or more vibration sensors (17-18, 91) is/are arranged for measuring horizontal vibration and vertical vibration from said sleeve bearing VFD motor and for producing measured vibration data.
  7. An arrangement according to claim 5 or to claim 6, wherein in generating said control torque: - a control torque reference is calculated by said frequency converter (11); and - control torque is generated by said frequency converter (11) corresponding to said control torque reference.
  8. An arrangement according to any of the claims 5-7, wherein said measured vibration data is utilized for suppression of vibration of said sleeve bearing VFD motor (12) at least at the low frequency critical speed frequency area/areas.
  9. An arrangement according to any of the claims 5-8, wherein said frequency converter (11) comprises: - a data gathering unit (92) arranged for gathering data, said gathered data including control data for said sleeve bearing VFD motor (12) and measured vibration data of said sleeve bearing VFD motor; and - a data analysis unit (93) arranged for analysing said gathered data and for determining the control torque for controlling vibration of said sleeve bearing VFD motor.
  10. An arrangement according to any of the claims 5-8, wherein said arrangement comprises a data analysis system (95, 97), and wherein said frequency converter (11) comprises: - a data gathering unit (92) arranged for gathering data, said gathered data including control data for said sleeve bearing VFD motor (12) and measured vibration data of said sleeve bearing VFD motor; and - a connection unit (94) arranged for transmitting said gathered data to said data analysis system (95, 97), - wherein said data analysis system (95, 97) is arranged for analysing said gathered data and for determining the control torque for controlling vibration of said sleeve bearing VFD motor.
  11. An arrangement according to claim 10, wherein said arrangement comprises a user apparatus (96), and - wherein said connection unit (94) arranged for transmitting said gathered data to said data analysis system (95, 97) via said user apparatus (96), and - wherein said user apparatus (96) is arranged for receiving measured vibration data of said sleeve bearing VFD motor from said one or more vibration sensors (17-18, 91) and for receiving said gathered data from said connection unit (94) and for forwarding said gathered data to said data analysis system (95, 97).
  12. A frequency converter (11) for controlling vibration of a sleeve bearing VFD motor (12), which frequency converter (11) is arranged: - to receive vibration data from one or more vibration sensors (17-18, 91) arranged for measuring at least horizontal vibration from said sleeve bearing VFD motor and for producing measured vibration data, said one or more vibration sensors (17-18, 91) comprising one or more vibration sensors (17-18, 91) of said sleeve bearing VFD motor (12); and - to generate a control torque for exerting said control torque on the stator of said sleeve bearing VFD motor (12) for controlling vibration of said sleeve bearing VFD motor (12), said control torque being determined utilizing said measured vibration data.
  13. A frequency converter (11) according to claim 12, wherein said one or more vibration sensors (17-18, 91) is/are arranged for measuring horizontal vibration and vertical vibration from said sleeve bearing VFD motor and for producing measured vibration data.
  14. A frequency converter (11) according to claim 12 or to claim 13, wherein in generating said control torque: - a control torque reference is calculated by said frequency converter (11); and - control torque is generated by said frequency converter (11) corresponding to said control torque reference.
  15. A frequency converter (11) according to any of the claims 12-14, comprising: - a data gathering unit (92) arranged for gathering data, said gathered data including control data for said sleeve bearing VFD motor (12) and measured vibration data of said sleeve bearing VFD motor; and - a data analysis unit (93) arranged for analysing said gathered data and for determining the control torque for controlling vibration of said sleeve bearing VFD motor.

Description

FIELD OF THE INVENTION The present invention relates to the field of electric drive devices and electric machines, such as electric motors and electric generators for industrial applications, and more particularly to a method, an arrangement and a frequency converter for controlling vibration of a sleeve bearing VFD motor. BACKGROUND OF THE INVENTION Electric drive arrangements are widely used for industrial applications, e.g. for providing and controlling electrical power and energy to various public and industrial applications as well as for driving and controlling various public and industrial applications. Electric drives are used in industry for different applications, such as for driving motors within the transportation industry, for driving different devices within the process and manufacturing industry as well as within the energy industry. There are applications commonly used for electric drives within the transportation industry for example in metro and railway traffic applications as well as in ship propulsion unit applications of the marine industry. Within the process and manufacturing industry, electric drives can be used for example in conveyer applications, in mixer applications or even in paper machine applications. Within the energy industry, electric drives can be used for example as electric drives for wind turbines of the wind power industry. Electric drives for electric machines, such as for electric motors and electric generators, may be divided into DC drives (DC, direct current) and AC drives (AC, alternating current). E.g. in a DC motor of a DC drive, a magnetic field is generated by the current through the field winding in the stator. This magnetic field is always maintained at right angles to the field generated by the armature winding. In this way, a DC motor's torque is generated, which torque can then be easily controlled in a DC drive by changing the armature current and keeping the magnetizing current constant. In a DC drive, also the DC motor speed can be controlled directly through armature current. Within electric drives, the AC drives may further be divided into frequency-controlled AC drives, flux-vector-controlled AC drives and into AC drives utilising direct torque control (DTC, Direct Torque Control). In flux-vector-controlled AC drives and in direct torque control AC drives the torque of the three-phase motor or generator can be controlled, whereas in frequency controlled AC drives the driven machine dictates the torque level. The avoidance of resonances strongly affects the structural design of large electric motors or generators. Traditionally, the dimensions of critical structural members are adjusted to fulfil this resonance criterion. There are some methods to decrease the excitation forces and increase damping of the bearings. Only in some exceptional cases, additional damping elements have been introduced to control vibrations of the lowest modes, i.e. the lowest natural frequencies. In electric machines, the foundations of the electric machine may vary significantly. Avoidance of resonances is usually the main design principle related to the motor vibrations. If foundation properties of the motor are known in site conditions, the vibration behaviour can be predicted, and the potential risks identified. In some cases, the corrective actions can be achieved by well-defined structural arrangements. In some cases, resonances can be avoided by separating the critical speeds, such as natural frequencies, from the operating speed range of the motor. However, the natural frequencies of the foundation system may differ a lot depending on the on-site conditions. The main difference is the change of natural frequencies as they are strongly affected by the flexible foundation. Occasionally but not every time, some harmful resonance vibrations are observed during the commissioning and operation of sleeve bearing VFD motors. However, the avoidance of all resonances is very difficult to achieve due to the variation of motor foundations on site and due to the large operating speed range of many VFD motors (VFD, variable frequency drive). All motors, such as variable frequency drive controlled motors, i.e. VFD motors, can be divided to sub-critical and super-critical designs. In sub-critical design, the natural frequency of the first bending mode of the rotor, i.e., critical speed, is above the operating speed, and in the super-critical design vice versa. The sub-critical design is usually preferred, but with increasing speeds and power the transition to super-critical designs is unavoidable. In practice, the super-critical design demands sleeve bearings. In VFD motors the sleeve bearings offer better damping characteristics than antifriction bearings. With sleeve bearing VFD motors this damping is needed to cross the critical speeds during start-ups and coast-downs. For direct-on-line motors, a thumb rule tells that the transition is justified in two-pole motors (3000 rpm)