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 for controlling a matrix converter with nine bidirectional power switches arranged in a 3null3 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:
A method for controlling positive or negative freewheeling paths of the phases of a matrix converter with nine bidirectional power switches arranged in a 3null3 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 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 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:
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 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:
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 180null. With control processes operating with phasor modulation, the offset of 180null represents a shift of the switching sequence by interchanging the initial zero phasors and/or the modulation half intervals.