摘要:
A switching device and method are disclosed for terminating a braking process of a three-phase AC motor. The braking process of the AC motor is performed by way of a first and second thyristor. During the braking process of the AC motor, in a first step the first thyristor is actuated in such a way that a braking current is fed to the AC motor, and therefore a torque which brakes the AC motor is produced. In a second step the second thyristor is actuated in such a way that, when the first thyristor is quenched, the braking current is taken on by the second thyristor and the braking torque is maintained. The two steps are repeated during the braking process; wherein the second step is suppressed during the braking process after a last actuation of the first thyristor.
摘要:
A method is disclosed for determining a phase failure in an electrical device for driving or monitoring a three-phase AC motor, wherein the electrical device comprises a first, a second and a third line. In order to detect a phase failure in a line in the three-phase electrical device, in particular in a soft starter, the phase failure in the third line is determined by analysing the first and second lines, wherein the analysis includes: determining a value which characterizes a phase shift between a current in the first and second lines, and outputting a signal if the value which has been determined is in a range of values which characterizes a phase failure in the third line.
摘要:
An embodiment of the invention relates to a switchgear which includes a control unit, a supply connection and a first current path. The first current path includes a first electromechanical switch and, connected in series to the first switch, a parallel connection of a second electromechanical switch to a semiconductor switch. The switchgear includes an energy accumulator and a measuring device. A control unit is capable of monitoring energy supply coming in through the supply connection. If the energy supply through the supply connection reaches a critical range, the control unit controls the output of the switching signals via the energy of the energy accumulator such that: in a first step, the semiconductor switch is switched to be electrically conducting and the second switch is then opened, and in a second step, the semiconductor switch is switched to be electrically non-conducting and the second switch is then opened.
摘要:
A method is disclosed for determining a phase failure in an electrical device for driving or monitoring a three-phase AC motor, wherein the electrical device comprises a first, a second and a third line. In order to detect a phase failure in a line in the three-phase electrical device, in particular in a soft starter, the phase failure in the third line is determined by analysing the first and second lines, wherein the analysis includes: determining a value which characterizes a phase shift between a current in the first and second lines, and outputting a signal if the value which has been determined is in a range of values which characterizes a phase failure in the third line.
摘要:
A switching device and method are disclosed for terminating a braking process of a three-phase AC motor. The braking process of the AC motor is performed by way of a first and second thyristor. During the braking process of the AC motor, in a first step the first thyristor is actuated in such a way that a braking current is fed to the AC motor, and therefore a torque which brakes the AC motor is produced. In a second step the second thyristor is actuated in such a way that, when the first thyristor is quenched, the braking current is taken on by the second thyristor and the braking torque is maintained. The two steps are repeated during the braking process; wherein the second step is suppressed during the braking process after a last actuation of the first thyristor.
摘要:
A method is disclosed for slowing-down control of an asynchronous machine, wherein the value of a start energy is determined and stored while the asynchronous machine is being run up from being stationary to the operating rotation speed. The asynchronous machine is braked, in the reversing mode, with braking energy which corresponds to the start energy multiplied by a correction factor wherein the correction factor assumes a value between 0 and 1. In at least one embodiment, the asynchronous machine is braked further by DC braking after braking has been carried out in the reversing mode.
摘要:
A method is disclosed for slowing-down control of an asynchronous machine, wherein the value of a start energy is determined and stored while the asynchronous machine is being run up from being stationary to the operating rotation speed. The asynchronous machine is braked, in the reversing mode, with braking energy which corresponds to the start energy multiplied by a correction factor wherein the correction factor assumes a value between 0 and 1. In at least one embodiment, the asynchronous machine is braked further by DC braking after braking has been carried out in the reversing mode.
摘要:
A device for connecting to a power network includes a circuit board, a first input-side connection point, to which a first phase of the power network can be connected, a second input-side connection point, to which a second phase of the power network can be connected, and a first and second electrical conductor. The first conductor is connected to the first input-side connection point and the second conductor is connected to the second input-side connection point inside the device. The first conductor is routed as a conductor trace in an interior layer of the circuit board and includes a constriction. The second conductor is routed past the constriction such that electrical insulation existing between the constriction of the first conductor and the second conductor is destroyed in the case of a short-circuit current, to provide an electrically conductive connection between the first and second conductor exists.
摘要:
Methods for controlling a voltage present at an electric fan during a startup of the fan are disclosed herein. The fan serves to generate a flow of air for cooling a device. The method includes applying an output voltage of a power supply, which serves to supply voltage to the device, to the fan; and switching on and switching off the output voltage of the power supply applied to the fan by a switch pulse-width-modulated-controlled by a control unit so that the Root Mean Square value of the current flowing through the fan is less than a startup current of the fan.