Abstract: A drive controller for a self-commutated converter providing a “safe stop” is described. The converter has two half-bridges, and the drive controller includes two control circuits having outputs operatively connected to respective converter valves of the half-bridges. Pulse inhibiting controllers are associated with the control circuits in one-to-one correspondence. The drive controller further includes a plurality of switches, each switch defining a disconnectable pulse inhibiting path and receiving control signals from one of the pulse inhibiting controllers. Each of the pulse inhibiting paths has an input which is connected to an external voltage, and an output which is connected, on one hand, via a diagnostic line to a corresponding pulse inhibiting controller and, on the other hand, to a control input of the corresponding control circuit. The switches can therefore be cyclically tested without service interruption.

Abstract: The simultaneous generation of interference currents with the same polarity is prevented in all converters of connected drives, without adversely affecting the time slice synchronization or the uniformity of the dynamic characteristics. This is achieved by taking advantage of the symmetry of the modulation. The triangles of the sinusoidal/triangular modulation do not overlap as in conventional drives; instead, the triangles of one group, corresponding to approximately half the number of drives, are offset by 180°. With control processes operating with phasor modulation, the offset of 180° represents a shift of the switching sequence by interchanging the initial zero phasors and/or the modulation half intervals.

Abstract: An electric machine includes a housing, and a fan assembly having a fan and a drive unit for operating the fan. The drive unit has an air gap, wherein at least part of the air gap is positioned outside the housing and wherein at least part of the drive unit is positioned inside the housing.

Abstract: A method and a device for bridging temporary power outages in a matrix converter are disclosed. In the event of a detected power failure, the matrix converter is disconnected from the power line and changes into a buffer mode in which a determined actual capacitor voltage space vector is regulated to a predetermined space vector. When the power line is reestablished, the actual capacitor space vector is synchronized and the matrix converter is reconnected to the power line during the synchronization. This allows a conventional matrix converter to take advantage of kinetic load buffering.

Abstract: An inverter includes a mains system side freewheeling pulse converter and a load-side freewheeling pulse converter, which are electrically connected on the DC side via a DC intermediate circuit. The mains system side and load-side freewheeling pulse converters each include switchable current valves in form of semiconductor switches that are made of silicon carbide with a high blocking voltage. The inverter can operate at higher voltages and frequencies, without affecting the load rating.

Abstract: A method and a device for bridging temporary power outages in a matrix converter are disclosed. In the event of a detected power failure, the matrix converter is disconnected from the power line and changes into a buffer mode in which a determined actual capacitor voltage space vector is regulated to a predetermined space vector. When the power line is reestablished, the actual capacitor space vector is synchronized and the matrix converter is reconnected to the power line during the synchronization. This allows a conventional matrix converter to take advantage of kinetic load buffering.

Abstract: A method and a device for shutting down a drive during a power outage are disclosed. The method and device include a matrix converter, several commutation capacitors on the power line side, a switch unit on the power line side and a resistor unit. During a power outage, the matrix converter is immediately disconnected from the power supply, and the resistor unit is connected to the input terminals of the matrix converter in such a way that the amplitude of a voltage applied to the resistor unit equals the amplitude of an actual capacitor voltage space vector, and a nominal speed vie is set to zero. This enables a drive with a matrix converter to be shut down during a power outage by way of a pulsed resistor.

Abstract: A method for controlling a matrix converter with nine bidirectional power switches arranged in a 3×3 switch matrix is described. Switching states of a modulation period are each calculated with associated time intervals by using a space vector modulation method. According to the invention, these calculated switching states are each divided into switching states of an output phase of the matrix converter, with time intervals assigned to the switching states, wherein the time intervals and the output-phase-related switching states are placed into one-to-one correspondence. Depending on the measured input voltages, the output-phase-related switching states with associated time intervals are combined into a pulse train of a modulation period, so that a sequential commutation always occurs to a nearest input voltage. This significantly reduces the switching losses of a matrix converter.

Abstract: An electronic power circuit includes at least one power semiconductor whose control inputs are connected to a trigger device and a power supply which, on the output side, is connected to terminals of the trigger device and, on the input side, is connected to an accessory device to which a supply voltage is applied. The power semiconductor is implemented as a self-conducting power semiconductor, which economically reduces the forward power losses and switching losses of an electronic power circuit.

Abstract: A method for controlling a matrix converter with nine bidirectional power switches arranged in a 3×3 switch matrix is described. Switching states of a modulation period are each calculated with associated time intervals by using a space vector modulation method. According to the invention, these calculated switching states are each divided into switching states of an output phase of the matrix converter, with time intervals assigned to the switching states, wherein the time intervals and the output-phase-related switching states are placed into one-to-one correspondence. Depending on the measured input voltages, the output-phase-related switching states with associated time intervals are combined into a pulse train of a modulation period, so that a sequential commutation always occurs to a nearest input voltage. This significantly reduces the switching losses of a matrix converter.

Abstract: The simultaneous generation of interference currents with the same polarity is prevented in all converters of connected drives, without adversely affecting the time slice synchronization or the uniformity of the dynamic characteristics. This is achieved by taking advantage of the symmetry of the modulation. The triangles of the sinusoidal/triangular modulation do not overlap as in conventional drives; instead, the triangles of one group, corresponding to approximately half the number of drives, are offset by 180°. With control processes operating with phasor modulation, the offset of 180° represents a shift of the switching sequence by interchanging the initial zero phasors and/or the modulation half intervals.

Abstract: A method for controlling positive or negative freewheeling paths of the phases of a matrix converter with nine bidirectional power switches arranged in a 3×3 switch matrix is described. Each power switch has two back-to-back series-connected semiconductor switches. Those semiconductor switches are actuated that have the most positive/negative line voltage to provide a negative/positive freewheeling path capable of carrying a negative/positive load current. The matrix converter can be immediately disconnected if an error is detected or if the matrix converter is inadvertently switched off, without damaging the matrix converter.

Abstract: A method for controlling positive or negative freewheeling paths of the phases of a matrix converter with nine bidirectional power switches arranged in a 3×3 switch matrix is described. Each power switch has two back-to-back series-connected semiconductor switches. Those semiconductor switches are actuated that have the most positive/negative line voltage to provide a negative/positive freewheeling path capable of carrying a negative/positive load current. The matrix converter can be immediately disconnected if an error is detected or if the matrix converter is inadvertently switched off, without damaging the matrix converter.

Abstract: A power converter device includes a power part accommodated in a first casing, and an electronic part accommodated in a separate second casing. The power part and the electronic part are connected to one another through a signal transmission arrangement, e.g. a cable or a radio communication. The power converter device thus has spatially separated power and electronic parts to realize a thermal separation as well and to enable a more compact overall configuration.

Abstract: An inverter includes a mains system side freewheeling pulse converter and a load-side freewheeling pulse converter, which are electrically connected on the DC side via a DC intermediate circuit. The mains system side and load-side freewheeling pulse converters each include switchable current valves in form of semiconductor switches that are made of silicon carbide with a high blocking voltage. The inverter can operate at higher voltages and frequencies, without affecting the load rating.

Abstract: The invention relates to a method and apparatus for recognizing a standstill condition when restarting a power converter-fed AC motor without a tachometer generator. According to an embodiment of the invention, a standstill recognition method includes first and second active phases decoupled by a passive phase. In each phase, time characteristics of the orthogonal current components of a measured motor current are recorded, and the energy component of current from the second active phase is further evaluated to generate an average value. This generated average value and an upper range value are then compared to a limiting value, which will be exceeded when the AC motor is at a standstill. Thus, through application of a current measurement and a simple evaluation, one can quickly determine the actual state of the power converter-fed AC motor when restarting.

Abstract: The present invention provides a current regulating method and associated apparatus for a voltage-injecting converter, wherein a flux-producing current component and a torque-producing current component of an actual current vector are regulated to corresponding components of a required current vector, whereby a precontrol variable is superimposed on each controller manipulated variable. According to the invention, the torque-producing controller manipulated variable acts on the flux-producing controller manipulated variable with delay as a function of a frequency variable, thereby providing a current regulating method which combines the advantages of two-component current regulation and active current regulation. This dual-action current regulation advantageously operates without requiring a structural switch between the two forms of current regulation.

Abstract: An actual value (u.sub.ixRF) of a signal (i.sub.xRF) affected by harmonics may be corrected. A harmonic signal (u.sub.iF) superimposed on the signal (i.sub.xRF) is generated using a harmonic-free setting signal(u.sub.yR), a known pulse pattern (.alpha..sub.1, .alpha..sub.2, ..., .alpha..sub.5) stored in the memory of a modulator, and an equivalent model of the control system. The mean value (u.sub.iF) of this harmonic signal (u.sub.iF) is determined by a second integrating actual value acquisition device. The mean value (u.sub.iF) is subtracted as a correction value from the actual value (u.sub.ixRF), which is affected by errors. In this way, an errorfree actual value (u.sub.ixR) is obtained for a signal (i.sub.xRF), the harmonics of which are not filtered out in the actual value determination by means of an integrating actual value acquisition device.

Abstract: In order to determine the rotor resistance of a rotating field machine, a current is impressed in the stator via a field-oriented control, which current has a harmonic component above the nominal frequency of the machine. From the current, the rotor position and a readjustable parameter value for the rotor resistance, a current model calculates a field-parallel EMF component EF1, the harmonic component EF1.sub..about. of which is isolated. In addition, a voltage model calculates from the current and the voltage, the EMF vector as the current component reference value EF1' and its harmonic component EF1'.sub..about.. A correction control CR1 readjusts the parameter r.sub.R of the rotor resistance until the difference of the two isolated harmonic EMF components disappears. The test signal has practically no influence on the flux and the torque of the machine. At the same time, the stator resistance r.sub.S and the stray inductance x.sub.St can be determined.