Siemens SINAMICS PERFECT HARMONY GH180 - Page 247

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Figure 8-3 Dual Frequency voltages added with normal 3-phase voltages
Note
Zero sequence voltage
Zero sequence voltage is the DC o󹪜set voltage.
The following is a scope picture of the two voltage vectors added together. The higher frequency
voltage waveform VA2 is riding on the lower frequency waveform VA1.
Figure 8-4 Dual Frequency Braking waveform
The 󹪝rst vector set controls the torque and 󹪞ux in the motor, and is nearly synchronous. The
second vector set induces losses in the motor to absorb the braking power returned by the 󹪝rst
vector set.
The amplitudes of the two vector sets are coordinated to best utilize the current and voltage
limitations of the converter. If the frequency of the loss-inducing vector set is chosen with the
Advanced Operating Functions
8.9 Dual-Frequency Braking
NXGPro+ Control Manual
Operating Manual, A5E50491925A 245