CataM
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Hello everyone,
Isolated converters (except half bridge) controlled via current mode control, there is no problem of flux imbalance in the transformer.
However, in order for the control to achieve this, i.e. have symmetrical magnetizing current shape, the "control reference" must be the same during both the positive and negative intervals of the current waveform, or, in other words, during the whole switching period of the waveform of the transformer.
By contrast, the current mode control, has a sampling frequency of 2*switching freq of the waveform at the transformer (fCMC=2*fXFMR).
In other words, the control loop must keep its signal constant during 2 periods of its sampling frequency (fCMC).
That being said, looks like it is useless to design the BW of the control loop regarding the sampling frequency of the CMC, but instead, it might be focused to half the sampling frequency.
I am not able to find any documentation regarding this in order to check the mentioned logical assumption, which is desirable since lower crossover frequency brings disadvantages.
Any comment on this is appreciated !
Isolated converters (except half bridge) controlled via current mode control, there is no problem of flux imbalance in the transformer.
However, in order for the control to achieve this, i.e. have symmetrical magnetizing current shape, the "control reference" must be the same during both the positive and negative intervals of the current waveform, or, in other words, during the whole switching period of the waveform of the transformer.
By contrast, the current mode control, has a sampling frequency of 2*switching freq of the waveform at the transformer (fCMC=2*fXFMR).
In other words, the control loop must keep its signal constant during 2 periods of its sampling frequency (fCMC).
That being said, looks like it is useless to design the BW of the control loop regarding the sampling frequency of the CMC, but instead, it might be focused to half the sampling frequency.
I am not able to find any documentation regarding this in order to check the mentioned logical assumption, which is desirable since lower crossover frequency brings disadvantages.
Any comment on this is appreciated !