Abstract:
A drive system for driving an electric motor includes a drive control unit and a frequency converter including a speed controller. The drive control unit is configured to: define a speed reference of the electric motor; preset operating parameters of the speed controller to provide a first response time of the speed controller, before a drive of the electric motor is initiated; adjust at least one operating parameter of the speed controller to provide a second response time of the speed controller, after the speed of the electric motor reaches a constant speed, wherein the second response time is slower than the first response time; and readjust the at least one operating parameter of the speed controller to provide the first response time, before a deceleration from the constant speed is initiated. A method is disclosed for controlling the drive system for driving the electric motor.
Abstract:
An elevator includes a control system for monitoring the load of a car, which control system is adapted to prevent the normal starting of the elevator, optionally also including relevelling, when there is an overload in the car. The elevator includes at least one position measuring device, speed measuring device and/or movement measuring device in order to determine the movement and/or position of the car, and the control system of the elevator is adapted to remove the prevention of normal starting when at least one said position measuring device, speed measuring device and/or movement measuring device detects that the car moved or is moving upwards in the elevator shaft. In the method, the control system of the elevator is used to determine the load situation of the car, including both the steps to prevent the normal starting of the elevator, optionally also including relevelling, when there is an overload in the car and to open some of the machinery brakes and to keep the remaining machinery brakes closed in order to determine the load situation.
Abstract:
An elevator includes a manual active dynamic braking function, which elevator includes an elevator control for operating at least one elevator car in at least one elevator driveway between landing floors in response to elevator calls, an AC elevator motor, which is able to generate power in a generator mode, a motor drive connected to the elevator control for the regulation of the speed of the elevator motor, including a frequency converter, whereby the frequency converter of the motor drive includes a rectifier bridge and an inverter bridge with semiconductor switch circuits, which rectifier bridge and inverter bridge are connected via a DC link, the motor drive further including a drive controller at least to control the semiconductor switches of the semiconductor switch circuits of the inverter bridge to regulate the elevator motor to a reference speed, whereby the semiconductor switch circuits of the inverter bridge are provided with diodes connected anti-parallel to the semiconductor switches, the motor drive including a safety logic for cutting off control pulses to the semiconductor switches, at least during power outage, at least one elevator brake is located in connection with the elevator motor and/or with a traction sheave of the elevator motor, a manual brake release lever is functionally linked to the elevator brake, movable between a rest position and at least one operating position to release the elevator brake manually. The motor drive includes a bypass switch being arranged to operate the safety logic, as to enable dynamical braking of the elevator motor by connecting the semiconductors of the semiconductor switch circuits of the inverter bridge with the drive controller, and the motor drive includes a DC supply circuit connected with the DC link, which is arranged to feed DC power at least to the drive controller and to the bypass switch to enable dynamic braking control of the semiconductor switches. The manual brake release lever is functionally connected with the bypass switch and is arranged to operate the bypass switch, when it is moved away from its rest position. Alternatively, the elevator includes a manual actuator, such as a key switch, disposed in the same location with the manual brake release lever, whereby the manual actuator is arranged to operate the manual bypass switch.
Abstract:
A method for controlling an elevator includes controlling the speed of a vertically moving elevator car during its run from a starting landing to a destination landing according to speed settings, the speed settings defining a constant target speed for the elevator car. The method includes obtaining measurement data of the ongoing run, which measurement data describes vertical speed and/or vertical acceleration of the vertically moving elevator car, determining whether the measurement data meets one or more predetermined criteria indicating unintended vertical speed and/or unintended vertical acceleration, and changing the speed settings of the current run by lowering the constant target speed from a first constant target speed to a second constant target speed if the measurement data meets said one or more predetermined criteria, continuing the run without intermediate stops to said destination landing. An elevator is provided to implement the method.
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:
The invention relates to a method for monitoring an activity of a user controlling an operation of a conveyor system with a remote control device, the method comprises: receiving control data from the remote control device, the control data defining user input provided at least in accordance with time; comparing the control data to a reference data; and setting, in accordance with a comparison between the control data and the reference data, a detection result to express one of the following: (i) a continuation of the operation of the conveyor system, (ii) a discontinuation of the operation of the conveyor system. The invention also relates to a control device, to a system, and to a computer program product.
Abstract:
According to an aspect, there is provided an elevator parking brake comprising brake pads configured to provide a braking force against a guide rail in a loading and unloading situation of an elevator car; and at least one sensor. The elevator parking brake is configured to allow a predetermined amount of movement within the elevator parking brake in the loading and unloading situation of the elevator car, and the at least one sensor is configured to provide at least one indication associated with the movement within the elevator parking brake in the loading and unloading situation of the elevator car.
Abstract:
It is desired that elevators are not operated when the brake is not completely released. Thus, the disengaging of brakes must be monitored or guaranteed otherwise. For providing guaranteed opening, the current for opening the brake is determined and then an additional current is provided to the brakes in order to guarantee the opening. The current for opening the brake is determined by doing a test sequence for each brake individually. In the test sequence, one brake is used to hold the elevator. Then, a momentum is applied to the elevator for moving the elevator car. The current is determined by increasing the current to the engaged brake gradually until the elevator moves. When the movement is detected, the current value is stored. When the elevator is operated regularly, the additional current is added to the stored value.
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 logic, which is connected to the input circuit and is configured to prevent the passage of control pulses to the control poles of the high-side and/or low-side switches of the motor bridge when the safety signal is disconnected, and also brake drop-out logic, which is connected to the input circuit and is configured to prevent passage of the control pulses to the control pole of the switch of the brake controller when the safety signal is disconnected.
Abstract:
Brake release sensors for an elevator can be replaced by an arrangement wherein the brake release is determined from the force caused by the brake. This is achieved by providing measuring device for measuring the weight of an elevator car between the brake and the motor body so that the weight of the elevator car is measured only when the brake is on.