Converter for electric power
The present invention relates to a converter for electric power having multiple sub-modules connected in series, the sub-modules having an energy storage unit and multiple power semiconductor circuits connected in parallel to the energy storage unit, and which causes an electric current to bypass a sub-module in case the breakdown of the sub-module occurs. To this end, the converter for electric power according to the present invention has multiple sub-modules connected to each other in series, the sub-modules having an energy storage unit and at least one power semiconductor circuit that is connected in parallel to the energy storage unit and comprises multiple power semiconductor switches and freewheeling diodes, wherein each of the sub-modules comprises a bypass switching unit, which is connected in parallel to any one of said at least one power semiconductor circuit, and bypasses an electric current via the bypass switching unit.
1. An electric power converter, comprising multiple sub-modules connected with each other in series,
wherein each of the multiple sub-modules includes an energy storage unit and one or more power semiconductor circuits connected to the energy storage unit in parallel,
wherein each of the one or more power semiconductor circuits includes multiple power semiconductor switches and free-wheel diodes,
wherein each of the sub-modules further includes a bypass switch unit that is connected to one of the one or more power semiconductor circuits and disposed between two output terminals,
wherein the electric power converter is configured to bypass a current through the bypass switch unit, and
wherein:
the bypass switch unit includes a first switch element connected to the one of the one or more power semiconductor circuits, a diode connected to the first switch element in anti-parallel, and a second switch element connected to the diode in parallel;
a cathode side of the first switch element is connected to an emitter side of one of the multiple power semiconductor switches of the one of the one or more power semiconductor circuits; and
the current flows through the diode and the first switch element when the sub-module fails, and the current is bypassed through the second switch element after a switching operation of the second switch element.
2. The electric power converter of claim 1 , wherein the first switch element includes a semiconductor switch or a power semiconductor switch, and the second switch element includes a mechanical switch.
3. The electric power converter according to claim 1 , wherein the first switch element includes an SCR.
4. An electric power converter, comprising multiple sub-modules connected with each other in series,
wherein each of the multiple sub-modules includes an energy storage unit and one or more power semiconductor circuits connected to the energy storage unit in parallel,
wherein each of the one or more power semiconductor circuits includes multiple power semiconductor switches and free-wheel diodes,
wherein each of the sub-modules further includes a bypass switch unit that is connected to one of the one or more power semiconductor circuits between two output terminals,
wherein the electric power converter is configured to bypass a current through the bypass switch unit, and
wherein:
the bypass switch unit includes a first switch element connected in parallel to the one of the one or more power semiconductor circuits and disposed between the two output terminals, a third switch element connected to the first switch element in anti-parallel, and a second switch element connected to the third switch element in parallel;
a cathode side of the first switch element is connected to an emitter side of one of the multiple power semiconductor switches ( 123 ) of the one of the one or more power semiconductor circuits ( 120 ); and
the current flows through the third switch element and the first switch element when the sub-module fails, and the current is bypassed through the second switch element after a switch operation of the second switch element.
5. The electric power converter of claim 4 , wherein the first switch element and the third switch element respectively include an SCR element.
6. The electric power converter of claim 5 , wherein an anode side of the third switch element is connected to the cathode side of the first switch element.
7. The electric power converter according to claim 1 , wherein a switching operation time of the second switch element is 6 to 10 milliseconds.
8. The electric power converter according to claim 2 , wherein the first switch element includes an SCR.
9. The electric power converter according to claim 4 , wherein a switching operation time of the second switch element is 6 to 10 milliseconds.