3-phase high-power UPS
According to one aspect, embodiments of the invention provide power converter circuitry including an input including a plurality of input lines each configured to be coupled to a phase of a multiphase AC power source having a sinusoidal waveform, a plurality of DC buses including a first positive DC bus having a first nominal DC voltage, a second positive DC bus having a second nominal DC voltage, a first negative DC bus having a third nominal DC voltage and a second negative DC bus having a fourth nominal DC voltage; a first power converter coupled to the input and configured to supply power from the multiphase AC power source to the plurality of DC buses during a first positive region of the sinusoidal waveform and a first negative region of the sinusoidal waveform; and a second power converter coupled to the input and configured to supply power from the multiphase AC power source to at least some of the plurality of DC buses during a second positive region of the sinusoidal waveform and a second negative region of the sinusoidal waveform.
1. Power converter circuitry comprising:
an input including a plurality of input lines each configured to be coupled to a phase of a multiphase AC power source having a sinusoidal waveform;
a plurality of DC buses including a first positive DC bus having a first nominal DC voltage, a second positive DC bus having a second nominal DC voltage, a first negative DC bus having a third nominal DC voltage and a second negative DC bus having a fourth nominal DC voltage;
a first power converter coupled to the input and configured to supply power from the multiphase AC power source to the plurality of DC buses during a first positive region of the sinusoidal waveform and a first negative region of the sinusoidal waveform; and
a second power converter coupled to the input and configured to supply power from the multiphase AC power source to at least some of the plurality of DC buses during a second positive region of the sinusoidal waveform and a second negative region of the sinusoidal waveform.
2. The power converter circuitry of claim 1 , wherein the first positive region and the second positive region include different regions of the sinusoidal waveform, and wherein the first negative region and the second negative region include different regions of the sinusoidal waveform.
3. The power converter circuitry of claim 1 , wherein the first power converter includes a positive boost circuit and a negative boost circuit,
wherein the positive boost circuit is coupled to each of the input lines and is configured to draw current during the first positive region of the sinusoidal waveform for each phase of the multiphase AC power signal, and
wherein the negative boost circuit is coupled to each of the input lines and is configured to draw current during the first negative region of the sinusoidal waveform for each phase of the multiphase AC power signal.
4. The power converter circuitry of claim 3 , wherein the second power converter includes a plurality of positive boost circuits and a plurality of negative boost circuits,
wherein the second power converter is configured to draw current during the second positive region using each of the plurality of positive boost circuits to draw current from a different one of the input lines of the multiphase AC power source, and
wherein the second power converter is configured to draw current during the second negative region using each of the plurality of negative boost circuits to draw power from a different one of the input lines of the multiphase AC power source.
5. The power converter circuitry of claim 1 , wherein the power converter circuitry is controlled such that a sum of current drawn at the input by the power converter circuitry provides a substantially sinusoidal current at all phase angles of the sinusoidal waveform.
6. The power converter circuitry of claim 1 , wherein the first positive region includes phase angles of the sinusoidal waveform in a region about a phase angle of a peak positive amplitude of the sinusoidal waveform,
wherein the first negative region includes phase angles of the sinusoidal waveform in a region about a phase angle of a peak negative amplitude of the sinusoidal waveform, and
wherein the second positive region and the second negative region include phase angles of the sinusoidal waveform in a region about a zero crossing of the sinusoidal waveform.
7. The power converter circuitry of claim 1 , wherein the second power converter is configured to supply power drawn from the multiphase AC power source to at least some of the plurality of DC buses at least for phase angles in a range of ±30 degrees about each zero crossing of the sinusoidal waveform.
8. The power converter circuitry of claim 1 , further comprising a rectifier coupled to the input, the rectifier including an output coupled to an input of the first power converter.
9. The power converter circuitry of claim 8 , further comprising a first switch configured to electrically isolate the rectifier from each phase of the multiphase AC power source, and a second switch configured to electrically isolate the second power converter from each phase of the multiphase AC power source.