摘要:
Method for controlling the drive of a conveyor device (10), especially in the form of an escalator or moving sidewalk, switchable between load operation and no-load operation, having a drive motor (26) and a frequency changer (42) controllable at least with respect to frequency and phase position of its output voltage, in which the drive motor (26) in load operation is fed with a line voltage with essentially constant line frequency and in no-load operation with the frequency changer output voltage, the phase difference between the phase position of the line voltage and the phase position of the frequency changer output voltage is determined, the phase position of the frequency changer output voltage is corrected according to the determined phase difference and therefore essentially brought into agreement with the phase position of the line voltage and switching is produced as soon as this agreement is reached.
摘要:
Each torque-producing phase current of a multi-phase motor is passed through a filter which includes an R/C shunt to ground and a series, current-compensated choke. Each choke has a winding in series with each phase so that the net current generated by phase currents in the windings is zero, and therefore the net flux generated by phase currents in the highly permeable core of the choke is zero at all times. However, there is significant inductive reactance created by the non-counterbalanced motor leakage currents, which prevent leakage currents from circulating through the motor. Thus, torque-producing motor currents can accurately be measured for feedback, without pollution from leakage currents. LEM current transducers allow use of small, proportional currents in the measuring and suppress inter-phase coupling.
摘要:
A power supply for an elevator drive includes a voltage input, a comparator for comparing the input voltage with a predetermined threshold, a transformer having a primary winding and a secondary winding connected to the elevator drive. The transformer has a single tapped primary winding. When the input voltage exceeds the predetermined threshold input, the comparator output causes power to be supplied to the primary winding via one of an end of the winding or the tapping of the winding, and when the input voltage is below the predetermined threshold, input power is supplied to the primary winding via the other of the end of the primary winding and the tapping of the winding.
摘要:
A power supply for an elevator drive, comprising a voltage input, a comparator for comparing the input voltage with a predetermined threshold, a transformer having a primary winding and a secondary winding connected to the elevator drive; where the transformer has a single tapped primary winding and wherein, when the input voltage exceeds the predetermined threshold input, the comparator output causes power to be supplied to the primary winding via one of an end of the winding or the tapping of the winding, and when the input voltage is below the predetermined threshold, input power is supplied to the primary winding via the other of the end of the primary winding and the tapping of the winding.
摘要:
Described is a method for operating a power semiconductor component. A power amplifier provided with a programmable logic is assigned to this power semiconductor component. In at least one embodiment, control signals for the power semiconductor component are transmitted to the power amplifier. The power semiconductor component is influenced by the power amplifier in dependence on these control signals. The type and manner in which the power semiconductor component is influenced is determined by the programming of the logic. The power amplifier can be sent programming signals which are then processed by a processor of the power amplifier. The programming of the logic is changed by the processor in dependence on the programming signals.
摘要:
Described is a method for operating a power semiconductor component. A power amplifier provided with a programmable logic is assigned to this power semiconductor component. In at least one embodiment, control signals for the power semiconductor component are transmitted to the power amplifier. The power semiconductor component is influenced by the power amplifier in dependence on these control signals. The type and manner in which the power semiconductor component is influenced is determined by the programming of the logic. The power amplifier can be sent programming signals which are then processed by a processor of the power amplifier. The programming of the logic is changed by the processor in dependence on the programming signals.