Converter circuit for damping overcurrent oscillations
View Patent ↗An exemplary converter circuit has a converter unit with plural actuatable power semiconductor switches, and the DC voltage side of which is connected to a capacitive energy storage circuit. The capacitive energy storage circuit has at least one capacitive energy store and at least one snubber network for limiting the rate of current or voltage rise on the actuatable power semiconductor switches of the converter unit. In order to reduce undesirable oscillations in an overcurrent in the capacitive energy storage circuit, the capacitive energy storage circuit has at least one passive nonactuatable damping unit having a unidirectional current-flow direction, where the passive nonactuatable damping unit has a diode and a damping resistor.
1. A converter circuit comprising:
a converter unit, having a plurality of actuatable power semiconductor switches, and a DC voltage side connected to a capacitive energy storage circuit, wherein the capacitive energy storage circuit has at least one capacitive energy store and at least one snubber network for limiting a rate of current or voltage rise on the actuatable power semiconductor switches of the converter unit,
the capacitive energy storage circuit including at least one passive nonactuatable damping unit having a unidirectional current-flow direction, wherein the passive nonactuatable damping unit has a diode and a damping resistor; and
the snubber network including a resistor, an inductance, a capacitance and a diode, wherein the resistor of the snubber network and the diode of the snubber network are connected in series, the series circuit having the resistor of the snubber network and the diode of the snubber network connected in parallel with the inductance of the snubber network, and the capacitance of the snubber network is connected to a connecting point between the resistor of the snubber network and the diode of the snubber network,
wherein if the capacitive energy storage circuit has a first and a second voltage potential, the snubber network is connected to first and second voltage potentials of the capacitive energy storage circuit, and the at least one passive nonactuatable damping unit is connected to the first and second voltage potentials of the capacitive energy storage circuit.
2. The converter circuit as claimed in claim 1 , wherein the diode of the at least one passive nonactuatable damping unit is connected in series with the damping resistor of the passive nonactuatable damping unit.
3. The converter circuit as claimed claim 2 , wherein the damping resistor of the passive nonactuatable damping unit is the resistor of the snubber network.
4. The converter circuit as claimed claim 1 , wherein the damping resistor of the passive nonactuatable damping unit is the resistor of the snubber network.
5. The converter circuit as claimed claim 1 , wherein the damping resistor of the passive nonactuatable damping unit is the resistor of the snubber network.
6. The converter circuit as claimed in claim 1 , wherein if the capacitive energy storage circuit has a first and a second voltage potential and a voltage zero potential, two snubber networks and two passive nonactuatable damping units are provided, one of the two snubber networks is connected to the first voltage potential of the capacitive energy storage circuit and to the zero voltage potential of the capacitive energy storage circuit, and another of the two snubber networks is connected to the second voltage potential of the capacitive energy storage circuit and to the zero voltage potential of the capacitive energy storage circuit,
wherein one of the two passive nonactuatable damping units is connected to the first voltage potential of the capacitive energy storage circuit and to the zero voltage potential of the capacitive energy storage circuit, and another of the passive nonactuatable damping units is connected to the second voltage potential of the capacitive energy storage circuit and to the zero voltage potential of the capacitive energy storage circuit.
7. The converter circuit as claimed in claim 6 , wherein the damping resistor of a respective one of the two passive nonactuatable damping units is the resistor of a respective one of the snubber networks.
8. A converter circuit comprising:
a converter unit, having a plurality of actuatable power semiconductor switches, and a DC voltage side connected to a capacitive energy storage circuit, wherein the capacitive energy storage circuit has at least one capacitive energy store and at least one snubber network for limiting a rate of current or voltage rise on the actuatable power semiconductor switches of the converter unit,
the snubber network including a resistor, an inductance, a capacitance and a diode, wherein the resistor of the snubber network and the diode of the snubber network are connected in series, the series circuit having the resistor of the snubber network and the diode of the snubber network connected in parallel with the inductance of the snubber network, and the capacitance of the snubber network is connected to a connecting point between the resistor of the snubber network and the diode of the snubber network,
wherein if the capacitive energy storage circuit has a first and a second voltage potential, the snubber network is connected to first and second voltage potentials of the capacitive energy storage circuit, and the at least one passive nonactuatable damping unit is connected to the first and second voltage potentials of the capacitive energy storage circuit.
9. The circuit as claimed in claim 8 , wherein the capacitive energy storage circuit includes at least one passive nonactuatable damping unit having a unidirectional current-flow direction, wherein the passive nonactuatable damping unit has a diode and a damping resistor.
10. The converter circuit as claimed in claim 9 , wherein the diode of the at least one passive nonactuatable damping unit is connected in series with the damping resistor of the passive nonactuatable damping unit.
11. The converter circuit as claimed claim 9 , wherein the damping resistor of the passive nonactuatable damping unit is the resistor of the snubber network.
12. The converter circuit as claimed in claim 9 , wherein if the capacitive energy storage circuit has a first and a second voltage potential and a voltage zero potential, two snubber networks and two passive nonactuatable damping units are provided, one of the two snubber networks is connected to the first voltage potential of the capacitive energy storage circuit and to the zero voltage potential of the capacitive energy storage circuit, and another of the two snubber networks is connected to the second voltage potential of the capacitive energy storage circuit and to the zero voltage potential of the capacitive energy storage circuit,
wherein one of the two passive nonactuatable damping units is connected to the first voltage potential of the capacitive energy storage circuit and to the zero voltage potential of the capacitive energy storage circuit, and another of the passive nonactuatable damping units is connected to the second voltage potential of the capacitive energy storage circuit and to the zero voltage potential of the capacitive energy storage circuit.
13. The converter circuit as claimed in claim 12 , wherein the damping resistor of a respective one of the two passive nonactuatable damping units is the resistor of a respective one of the snubber networks.