AC power supply PCR-LE series

Appendix


Phase setting for multi-phase output

This page explains how to set phase angles for multi-phase output. For details on the operation of starting and ending phase angles, see “Switching steps at specific phase angles”. For details on the operation of sudden phase changes, see”Suddenly changing the phase”.

- Note -

For the U phase sudden-phase-change settings, specify the starting phase angle, ending phase angle, and sudden phase change.

For the V phase sudden-phase-change settings, set the U-V phase difference.

For the W phase sudden-phase-change settings, set the U-W phase difference.

In the example below, the U phase suddenly changes from 0° to 180° when step 1 begins.

Because the U-V and U-W phase differences in step 1 are set to OFF, the U-V phase difference remains at 120° and the U-W phase difference remains at 240°. When the U phase is 0°, the V phase is 240°, because it is behind by 120°. The W phase is 120°, because it is behind by 240°. The V phase suddenly changes from 240° to 60° when step 1 begins. The W phase suddenly changes from 120°to 300°.

60100.jpg

STEP

0

1

S.PHASE [deg]

Starting phase angle

FREE

180

E.PHASE [deg]

Ending phase angle

0

FREE

PHAS. CNG

Sudden phase change

OFF

ON

U-V PHAS [deg]

U-V phase difference

OFF

OFF

U-W PHAS [deg]

U-W phase difference

OFF

OFF

  

Next, we will explain how to set the steps so that only the U phase suddenly changes.

In the example below, the U phase suddenly changes from 0° to 30° when step 1 begins. The waveforms of the V and W phases are continuous.

When step 1 begins, the U phase changes from 0° to 30°. If the U-V and U-W phase differences are set to OFF, the V phase will suddenly change from 240° to 270°, and the W phase will suddenly change from 120° to 150°. Because we want only the U phase to change suddenly, we add 30° to the phase differences (150° for the V phase and 270° for the W phase) so that the V and W phases will be continuous. When these settings are made, the waveforms of the V and W phases will be continuous.

60145.jpg

STEP

0

1

S.PHASE [deg]

Starting phase angle

FREE

30

E.PHASE [deg]

Ending phase angle

0

FREE

PHAS. CNG

Sudden phase change

OFF

ON

U-V PHAS [deg]

U-V phase difference

OFF

150

U-W PHAS [deg]

U-W phase difference

OFF

270

You can also set the U phase offset to cause the U phase to suddenly change, but in this case, the U-V/U-W phase difference settings will be offset from the actual phase difference. To avoid confusion, we recommend that you turn off the U phase offset.

For details, see the next section, “Phase sweep”

Lastly, we will explain how to set the steps so that the V and W phases suddenly change. To suddenly change the V phase, set the U-V phase difference. To suddenly change the W phase, set the U-W phase difference.

In the example below, the U-V phase difference is suddenly changed from 120° to 90° when step 1 begins. The waveforms of the U and W phases are continuous.

Step 0 ends when the U phase is 180°. When the U phase is 180° in step 0, the V-phase is 60°, because the U-V phase difference is 120°. Because the U-V phase difference is changed to 90° in step 1, the V-phase starts at 180°-90° = 90°. This means that only the V phase suddenly changes from 60° to 90° when step 1 begins.

60162.jpg

STEP

0

1

S.PHASE [deg]

Starting phase angle

FREE

FREE

E.PHASE [deg]

Ending phase angle

FREE

FREE

PHAS. CNG

Sudden phase change

OFF

OFF

U-V PHAS [deg]

U-V phase difference

OFF

90

U-W PHAS [deg]

U-W phase difference

OFF

OFF

The example below shows a sudden phase change in which step 1 begins at 0° when step 0 ends with the V phase at 90°. The waveforms of the U and W phases are continuous.

Because the U-V phase difference is 120°, the V phase is 90° when the U phase is 210°. We want to the V phase to change at 90°, so we set the starting phase angle of step 1 to 210°. The U phase angle is 210° when step 1 begins. To make the V phase suddenly change to 0°, we set the U-V phase angle to 210°. The W phase is continuous, so we leave the U-W phase difference at OFF.

When the U phase angle of step 0 reaches 210°, step 1 begins. The V phase suddenly changes from 90°to 0°.

60172.jpg

STEP

0

1

S.PHASE [deg]

Starting phase angle

FREE

210

E.PHASE [deg]

Ending phase angle

FREE

FREE

PHAS. CNG

Sudden phase change

OFF

OFF

U-V PHAS [deg]

U-V phase difference

OFF

210

U-W PHAS [deg]

U-W phase difference

OFF

OFF

  

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Appendix