Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B66—HOISTING; LIFTING; HAULING
  • B66B—ELEVATORS; ESCALATORS OR MOVING WALKWAYS
  • B66B1/00—Control systems of elevators in general
  • B66B1/24—Control systems with regulation, i.e. with retroactive action, for influencing travelling speed, acceleration, or deceleration
  • B66B1/28—Control systems with regulation, i.e. with retroactive action, for influencing travelling speed, acceleration, or deceleration electrical
  • B66B1/30—Control systems with regulation, i.e. with retroactive action, for influencing travelling speed, acceleration, or deceleration electrical effective on driving gear, e.g. acting on power electronics, on inverter or rectifier controlled motor

Definitions

• the present invention relates to an elevator control system as defined in the preamble of claim 1.
• Finnish patent application FI A 944583 presents a solution according to which an elevator drive machine using a synchronous motor can in principle be started on the basis of all data defined in any case in the elevator or in its machinery.
• the load weight signal is always available because of other requirements regarding elevator load data, such as overload data.
• the object of the present invention is to disclose a new type of system for controlling an elevator drive machine using a synchronous motor. Specifically, the invention discloses a new type of system that reduces the costs involved in eleva ⁇ tor control.
• the system of the invention is used to control a synchronous elevator motor fed by a frequency converter.
• the system com- prises a model of the mechanical system, which is divided into a static part and a variable part dependent on load weight data.
• the motor torque and speed requirements are calculated according to the mechanical system model as well as according to a speed reference and/or position reference.
• the system also comprises a parametrised model of the motor. In principle, the only variable in the system is the load weight data, everything else is known in advance.
• the motor control quantities are calculated on the basis of the parametrised motor model and the torque and speed require- ments. Thus, the entire elevator movement along its route from the starting acceleration to the final stop is defined and translated into motor control quantities prior to the departure of the elevator.
• the models com- prised in the control system, the model of the mechanical system or the parametrised motor model are supplied from outside the control system. Therefore, the models are known beforehand from some other context.
• the models can be generated on the basis of measurement results obtained from test operation executed by the control system.
• the system measures the load weight data continuously.
• This load weight data can be utilised e.g. in control system stabilisation during elevator travel .
• the advantages of the present invention include a small need for measurements as the only quantity to be measured is the load weight data.
• the mass of the system remains substantially constant after the elevator doors have been closed, so the weighing only needs to be carried out at least once during each passage of the elevator.
• Another consequence of the system is a simple structure.
• an elevator implementation according to the system of the invention is economical as compared with prior art.
• the mechanical system 3 of the elevator system is divided into two parts, a static part 1 and a variable part 2 dependent on the load weight data.
• the static part 1 practically remains constant all the time. Its parameters include e.g. the mass of the elevator car and that of the counterweight as well as the frictional forces.
• the variable part consists of the load of the elevator.
• the load weight data can be assumed to be constant from the moment the elevator doors are closed.
• the speed reference is obtained e.g. on the basis of the motor power, which is known.
• the position reference is obtained from the desired travel between floors, e.g. in the form of user's selection via the push-button panel of the elevator.
• the require- ments regarding motor torque and speed can be calculated.
• the motor control quantities 7 to be used can be calculated in advance.
• the motor control quantities include e.g. the angle of the magnetic field of the stator and the current to be supplied to the motor.
• the control quantities are stored in memory and fed to the motor in sequence at specified points of time, with the result that the elevator executes the functions comprised in the model provided in the system.

Landscapes

• Engineering & Computer Science (AREA)
• Automation & Control Theory (AREA)
• Control Of Electric Motors In General (AREA)
• Elevator Control (AREA)
• Control Of Ac Motors In General (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (2)

Family

ID=8549939

Family Applications (1)

Country Status (3)

Cited By (3)

Citations (3)

• 1997
  • 1997-11-13 FI FI974229A patent/FI111618B/sv not_active IP Right Cessation
• 1998
  • 1998-11-13 WO PCT/FI1998/000893 patent/WO1999028229A2/sv active Application Filing
  • 1998-11-13 AU AU12371/99A patent/AU1237199A/en not_active Abandoned

Patent Citations (3)

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