Abstract: Invention is related to a method for controlling an alternating current electric machine with a frequency converter including a controllable machine bridge and a controllable line bridge, and a corresponding frequency converter. The method comprises calculating a line bridge control signal, controlling line current through the line bridge using the line bridge control signal, measuring or estimating rotor pole position of the electric machine, calculating a machine bridge control signal as a function of the rotor pole position, updating the machine bridge control signal when the rotor pole position changes, and controlling current of the electric machine through the machine bridge using the machine bridge control signal.

Abstract: A safety arrangement of an elevator and a method for monitoring electrical safety in an elevator system is disclosed. The safety arrangement of an elevator includes a motor drive of the elevator, which motor drive includes a main circuit, an accessible conducting part, which is earthed, an insulator, which is adapted to electrically insulate the aforementioned conducting part from the aforementioned main circuit and also a monitoring circuit, which is configured to determine an earth fault of the aforementioned main circuit occurring via the aforementioned conducting part. The monitoring circuit is configured to form a signal indicating the danger of electric shock in the motor drive of the elevator, if the aforementioned earth fault is diagnosed.

Abstract: Stall condition in an elevator is potentially dangerous situation if it causes slack to the ropes of the elevator. In such situation a counterweight or elevator car does not move even if the hoisting machine is still operating. This situation may be prevented by stopping the elevator as early as possible after detecting such stall condition. The detection of the stall condition is based on monitoring the torque generated by the hoisting machine of the elevator. When rapid change in the torque is detected a stall condition is suspected. The elevator may be stopped or an alarm may be launched when the stall condition is suspected.

Abstract: The invention allows inspection tests for an elevator without additional test weights. An empty elevator car and its counterweight are balanced by filling in weight pieces to the counterweight. 100% load of the elevator car in regard to unbalance is configured by moving unused counterweight pieces inside the elevator car. Inspection tests requiring the 100% load in regard to unbalance are performed. 125% load of the elevator car is simulated with 50% load and 125% speed of the elevator car. Inspection tests requiring the 125% load in regard to unbalance are performed. A final counterweight is configured by moving its weight pieces from the elevator car to the counterweight. Inspection tests requiring the final counterweight are performed.

Abstract: The invention relates to a method and an apparatus. In the method there is determined a speed limit or an acceleration limit for an elevator car based on elevator state information, the elevator state information comprising at least information on whether the elevator car is being driven or whether the elevator car is in a floor. Power supply to the motor is disabled and brakes are applying for braking movement of the elevator car. Speed or acceleration of the elevator car is measured, in response to the applying of the at least one brake and the disabling of the power supply to the motor. It is determined whether the at least one of speed and acceleration of the elevator car exceeds the respective at least one of the speed limit and the acceleration limit. Thereupon, power supply to the motor is enabled for stabilizing movement of the elevator car.

Abstract: A drive device of an elevator includes a DC bus, a motor bridge connected to the DC bus for the electricity supply of the elevator motor, which motor bridge includes high-side and low-side switches for supplying electric power from the DC bus to the elevator motor when driving with the elevator motor, and also from the elevator motor to the DC bus when braking with the elevator motor, a control circuit of the motor bridge, with which control circuit the operation of the motor bridge is controlled by producing control pulses in the control poles of the high-side and low-side switches of the motor bridge, a brake controller, which comprises a switch for supplying electric power to the control coil of an electromagnetic brake, a brake control circuit, with which the operation of the brake controller is controlled by producing control pulses in the control pole of the switch of the brake controller, an input circuit for the safety signal to be disconnected/connected from outside the drive device, drive prevention

Abstract: A brake controller, an elevator system and a method for performing an emergency stop are provided. The brake controller includes an input for connecting the brake controller to the DC intermediate circuit of the frequency converter driving the hoisting machine of the elevator, an output for connecting the brake controller to the electromagnet of the brake, a switch for supplying electric power from the DC intermediate circuit of the frequency converter driving the hoisting machine of the elevator via the output to the electromagnet of a brake, and also a processor with which the operation of the brake controller is controlled by producing control pulses in the control pole of the switch of the brake controller.

Abstract: A safety arrangement of an elevator, which includes sensors configured to indicate functions that are critical from the viewpoint of the safety of the elevator, and also a safety circuit, with which the data formed by the sensors indicating the safety of the elevator is read. The safety arrangement includes a drive device for driving the hoisting machine of the elevator. The drive device includes a DC bus, and also a motor bridge connected to the DC bus for the electricity supply of the elevator motor. The motor bridge includes high-side and low-side switches for supplying electric power from the DC bus to the elevator motor when driving with the elevator motor, and also from the elevator motor to the DC bus when braking with the elevator motor.

Abstract: The invention relates to a control apparatus of an elevator and also to a method for controlling an elevator motor.

Abstract: A frequency converter and a method for determining the position of the rotor of an electric machine are provided. The frequency converter includes a load bridge and a control of the load bridge, for supplying electricity between the load bridge and an electric machine connected to the load bridge. The frequency converter includes a determination for at least one electrical parameter of the electric machine, and includes a determination for the position of the rotor of the electric machine. The load bridge is fitted to supply a first alternating electricity excitation signal, which is formed in relation to the electrical angle of the electric machine, to the electric machine. The frequency converter is further fitted to determine the first alternating electricity response signal corresponding to the first alternating electricity excitation signal, and the position of the rotor is determined on the basis of the first alternating electricity response signal.

Abstract: An adjustment device for controlling the electric drive of an elevator in connection with a voltage reduction of the supplying network is disclosed. The electric drive of an elevator includes an electric motor and a power supply apparatus of for adjusting the supply voltage of the electric motor. The adjustment device includes a device configured to control the power supply apparatus and also a speed regulator for adjusting the speed of the electric motor. The adjustment device is arranged to determine the output voltage of the power supply apparatus of the electric motor in relation to the permitted maximum value of the output voltage, and the adjustment device is arranged to interrupt the operation of the speed regulator but to continue the operation of the power supply apparatus of the electric motor when the output voltage of the power supply apparatus of the electric motor reaches the permitted maximum value.

Abstract: The invention relates to a method and to devices for starting up an electric drive of an elevator. In the method a sensor that detects the direction of movement of the elevator car is fitted into the elevator system, the elevator car is brought into a state of movement, the direction of movement of the elevator car is detected from the measuring signal of the aforementioned sensor that detects the direction of movement of the elevator car and also the drive direction of the electric drive is connected in the control of the electric drive to the detected direction of movement of the elevator car.

Abstract: The invention concerns a method and apparatus (28) for determining an angle (9) by means of a resolver (3). In the method, an excitation signal (29) of constant frequency is supplied to the resolver (3), the resolver response signals (13, 14) are measured, successive (16) measurements of each response signal are stored into a sample buffer (5), FIR filtering (10) is computed for the response signal values (16) present in the sample buffer (5) at the instant of computation, the computation points (23, 24) and the set of computation result values (18) corresponding to these points are stored in memory, at least two sets of values (18, 19) of computation results are compared to each other and of these the value set Amax (19) which contains the highest computation result as an unsigned value is selected, and FIR filtering (10) is repeatedly computed at the computation points (25, 26) corresponding to value set Amax (19).

Abstract: A frequency converter and a method for determining the position of the rotor of an electric machine are provided. The frequency converter includes a load bridge and a control of the load bridge, for supplying electricity between the load bridge and an electric machine connected to the load bridge. The frequency converter includes a determination for at least one electrical parameter of the electric machine, and includes a determination for the position of the rotor of the electric machine. The load bridge is fitted to supply a first alternating electricity excitation signal, which is formed in relation to the electrical angle of the electric machine, to the electric machine. The frequency converter is further fitted to determine the first alternating electricity response signal corresponding to the first alternating electricity excitation signal, and the position of the rotor is determined on the basis of the first alternating electricity response signal.

Abstract: An adjustment device for controlling the electric drive of an elevator in connection with a voltage reduction of the supplying network is disclosed. The electric drive of an elevator includes an electric motor and a power supply apparatus of for adjusting the supply voltage of the electric motor. The adjustment device includes a device configured to control the power supply apparatus and also a speed regulator for adjusting the speed of the electric motor. The adjustment device is arranged to determine the output voltage of the power supply apparatus of the electric motor in relation to the permitted maximum value of the output voltage, and the adjustment device is arranged to interrupt the operation of the speed regulator but to continue the operation of the power supply apparatus of the electric motor when the output voltage of the power supply apparatus of the electric motor reaches the permitted maximum value.

Abstract: The invention relates to a method and to devices for starting up an electric drive of an elevator. In the method a sensor that detects the direction of movement of the elevator car is fitted into the elevator system, the elevator car is brought into a state of movement, the direction of movement of the elevator car is detected from the measuring signal of the aforementioned sensor that detects the direction of movement of the elevator car and also the drive direction of the electric drive is connected in the control of the electric drive to the detected direction of movement of the elevator car.

Abstract: A frequency converter and a method for determining the position of the rotor of an electric machine are provided. The frequency converter includes a load bridge and a control of the load bridge, for supplying electricity between the load bridge and an electric machine connected to the load bridge. The frequency converter includes a determination for at least one electrical parameter of the electric machine, and includes a determination for the position of the rotor of the electric machine. The load bridge is fitted to supply a first alternating electricity excitation signal, which is formed in relation to the electrical angle of the electric machine, to the electric machine. The frequency converter is further fitted to determine the first alternating electricity response signal corresponding to the first alternating electricity excitation signal, and the position of the rotor is determined on the basis of the first alternating electricity response signal.

Abstract: The invention concerns a method and an apparatus for controlling a three-or-more-phase motor driven by a frequency converter. In the method, a change-over switch of the frequency converter is controlled to a continuously conducting state and at the same time the phase voltages or phase currents of the other phases are controlled by switching the change-over switches in those motor phases at a switching frequency substantially higher than the frequency of the fundamental wave of the phase voltage or phase current. The apparatus comprises in conjunction with the frequency converter a number of change-over switches, at least one change-over switch for each motor phase. The change-over switches comprise controllable change-over contacts. The apparatus further comprises in conjunction with the frequency converter means for determining the motor phase currents and means for controlling the change-over contacts.

Abstract: A determination of the loading state of an elevator system and also a method for determining the loading state of an elevator system is described. The elevator system includes an elevator car and also a motor drive for moving the elevator car. The loading state of the elevator system is determined on the basis of the position deviation of the elevator motor that occurs during the determination of the loading state.

Abstract: The invention relates to a method and an appliance for monitoring the safety of a transport system. The transport system includes a transport appliance and also a synchronous motor for moving the transport appliance. In the method, the motion information of the transport appliance is determined with two channels, and if the determined motion informations deviate from each other by more than the set limit value, an emergency stop is executed.