Hi all, thanks for taking a look at my post. As a hobby project, I am designing a simple 12VDC-5VDC power supply and am having trouble finding literature explaining how to implement compensation in the feedback loop at the error amplifier.
I have read chapters 7-9 of R.W. Erickson's "Fundamentals of Power Electronics 2nd Ed.", so I have a pretty good understanding of what type of frequency response I want the closed loop system to have and how to decide where to place the poles, zero, and inverted zero of a lead-lag compensator, but I cannot find much useful information on how to implement those features with a resistive/capacitive compensation network.
I did find the Texas Instruments released paper: "Designing Stable Control Loops" by Dan Mitchell and Bob Mammano ( http://www.ti.com/lit/ml/slup173/slup173.pdf ) and used the paper's guidelines for setting up a compensation network for a buck converter similar to the one I am working on. However, when I try to simulate it (I am using Simetrix 7.10), the feedback does not work if I have C2 populated. C2 is the capacitor placed in series with the feedback resistor of the error amplifier op amp. It is labeled C2 in the TI paper (p. 14) and the attached schematic print. I think the capacitor is blocking the DC feedback signal from making the full loop, but the TI paper explicitly shows it in that location of the network.
If anyone could expalain to me how to physically implement a compensation network (preferably of a lead-lag or PID controller type) or where to find information on the topic, I would greatly appreciate the help. Thank you!
I have read chapters 7-9 of R.W. Erickson's "Fundamentals of Power Electronics 2nd Ed.", so I have a pretty good understanding of what type of frequency response I want the closed loop system to have and how to decide where to place the poles, zero, and inverted zero of a lead-lag compensator, but I cannot find much useful information on how to implement those features with a resistive/capacitive compensation network.
I did find the Texas Instruments released paper: "Designing Stable Control Loops" by Dan Mitchell and Bob Mammano ( http://www.ti.com/lit/ml/slup173/slup173.pdf ) and used the paper's guidelines for setting up a compensation network for a buck converter similar to the one I am working on. However, when I try to simulate it (I am using Simetrix 7.10), the feedback does not work if I have C2 populated. C2 is the capacitor placed in series with the feedback resistor of the error amplifier op amp. It is labeled C2 in the TI paper (p. 14) and the attached schematic print. I think the capacitor is blocking the DC feedback signal from making the full loop, but the TI paper explicitly shows it in that location of the network.
If anyone could expalain to me how to physically implement a compensation network (preferably of a lead-lag or PID controller type) or where to find information on the topic, I would greatly appreciate the help. Thank you!
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