Impute DC link (IDCL) cell based power converters and control thereof
Power flow controllers based on Imputed DC Link (IDCL) cells are provided. The IDCL cell is a self-contained power electronic building block (PEBB). The IDCL cell may be stacked in series and parallel to achieve power flow control at higher voltage and current levels. Each IDCL cell may comprise a gate drive, a voltage sharing module, and a thermal management component in order to facilitate easy integration of the cell into a variety of applications. By providing direct AC conversion, the IDCL cell based AC/AC converters reduce device count, eliminate the use of electrolytic capacitors that have life and reliability issues, and improve system efficiency compared with similarly rated back-to-back inverter system.
1. An apparatus for controlling power flow between a first AC source and a second AC source, comprising:
an imputed DC link (IDCL) cell comprising:
a plurality of power switches;
a voltage sharing module coupled across each of the plurality of power switches, wherein the plurality of power switches share voltage equally; and
a transformer coupled to the IDCL cell, wherein an input voltage to the IDCL cell is a fraction of a voltage of the first AC source.
2. The apparatus of claim 1 , wherein the plurality of power switches are four IGBTs.
3. The apparatus of claim 1 , further comprising a control module, wherein the control module generates a set of switching pulses to modulate the plurality of power switches.
4. The apparatus of claim 1 , wherein the voltage sharing module is an active snubber, the active snubber projecting a half-wave rectified waveform across each power switch.
5. The apparatus of claim 1 , further comprising a set of IDCL cells, wherein the set of IDCL cells are coupled in series and share voltage equally.
6. The apparatus of claim 1 , further comprising a set of IDCL cells, wherein the set of IDCL cells are coupled in parallel.
7. An apparatus for controlling power flow between a first AC source and a second AC source, comprising:
an imputed DC link (IDCL) cell comprising:
a plurality of power switches, wherein the plurality of power switches are four IGBTs; and
a voltage sharing module coupled across each of the plurality of power switches, wherein the plurality of power switches share voltage equally;
wherein the plurality of power switches are coupled to form an AC chopper, ai a collector of the first IGBT is coupled to a collector of the second IGBT, the emitter of the second IGBT is coupled to the collector of the third IGBT, and the emitter of the third IGBT is coupled to the emitter of the fourth IGBT.
8. A method of converting a passive device between a first AC source and a second AC source to a power flow controller controlling the power flow between the first AC source and a second AC source, comprising:
coupling an imputed DC link (IDCL) cell to the passive device, wherein the imputed DC link cell comprising:
a plurality of power switches, the plurality of power switches coupled as an AC chopper; and
a voltage sharing module coupled across each of the plurality of power switches, wherein the plurality of power switches share voltage equally;
wherein the passive device is a transformer and an input voltage to the IDCL cell is a fraction of a voltage of the first AC source.
9. The method of claim 8 , wherein the plurality of power switches are four IGBTs.
10. The method of claim 8 , further comprising generating a set of switching pulses to modulate the plurality of power switches.
11. The method of claim 8 , wherein the voltage sharing module is an active snubber, the active snubber projecting a half-wave rectified waveform across each power switch.
12. A method of converting a passive device between a first AC source and a second AC source to a power flow controller controlling the power flow between the first AC source and a second AC source, comprising:
coupling an imputed DC link (IDCL) cell to the passive device, wherein the imputed DC link cell comprising:
a plurality of power switches, wherein the plurality of power switches are four IGBTs, the plurality of power switches coupled as an AC chopper; and
a voltage sharing module coupled across each of the plurality of power switches, wherein the plurality of power switches share voltage equally;
wherein the plurality of power switches are coupled to form an AC chopper, an collector of the first IGBT is coupled to an collector of the second IGBT, the emitter of the second IGBT is coupled to the collector of the third IGBT, and the emitter of the third IGBT is coupled to the emitter of the fourth IGBT.