Power conversion apparatus having Scott-T transformer
A power converter having a Scott-T transformer includes a direct current to alternating current converter configured to have at least two multilevel converters converting input direct current power to alternating current power, a Scott-T transformer configured to operate in medium frequency of several hundreds of Hz to several tens of kHz, to transform a voltage level of the alternating current power from each of the at least two multilevel converters of the direct current to alternating current converter into three-phase alternating current power, and to output the three-phase alternating current power, and an alternating current to direct current converter configured to convert the three-phase alternating current power from the Scott-T transformer to direct current power.
1. A power converter having a Scott-T transformer, comprising:
a direct current to alternating current converter configured to have at least two multilevel converters converting input direct current power to alternating current power;
the Scott-T transformer configured to operate in medium frequency of several hundreds of Hz to several tens of kHz, to transform a voltage level of the alternating current power from each of the at least two multilevel converters of the direct current to alternating current converter into three-phase alternating current power, and to output the three-phase alternating current power; and
an alternating current to direct current converter configured to convert the three-phase alternating current power from the Scott-T transformer to direct current power.
2. The power converter of claim 1 , wherein the direct current to alternating current converter converts an input direct current medium voltage and direct current power of a bipolar grid into an alternating current medium voltage and two phase alternating current powers having a medium frequency.
3. The power converter of claim 2 , wherein the Scott-T transformer converts the alternating current power from the direct current to alternating current converter into the three-phase alternating current power of a low voltage of several kV or lower in accordance with a predetermined turn ratio.
4. The power converter of claim 3 , wherein the alternating current to direct current converter converts alternating current power from the Scott-T transformer into the direct current power of a low voltage of 1500V or lower.
5. The power converter of claim 1 , wherein the alternating current to direct current converter includes three legs connected to one another in parallel, each having two semiconductor switches connected to each other in series.
6. The power converter of claim 5 ,
wherein the three legs of the alternating current to direct current converter operates by six-step operation, and
wherein the power converter is configured as a bidirectional power converter.
7. The power converter of claim 1 , wherein the alternating current to direct current converter includes three legs connected to one another in parallel, each having two diodes connected to each other in series.
8. The power converter of claim 7 , wherein the power converter is configured as a unidirectional power converter.
9. The power converter of claim 1 , wherein at least one of the direct current to alternating current converter and the alternating current to direct current converter operates in a medium frequency of several hundreds of Hz to several tens of kHz.
10. The power converter of claim 1 , wherein a sub-module of the multilevel converter includes a half bridge, a full bridge, or combination of a half bridge and a full bridge.