l***g
发帖数: 1035 | 1 pe guys.. have u controlled a boost with dsp? since the boost duty cycle is
not linear with the Vout, how do you close the loop? linearization or brutal
force pi? |
c*******r
发帖数: 275 | 2 same as analog control, PID compensation is enough.
note, make conservative design to stable the loop at all load conditions
since control to output transfer function of boost changes with loads.
is
brutal
【在 l***g 的大作中提到】
: pe guys.. have u controlled a boost with dsp? since the boost duty cycle is
: not linear with the Vout, how do you close the loop? linearization or brutal
: force pi?
|
l***g
发帖数: 1035 | 3 thanks
right it's non linear so the dynamic response would be non linear. I have on
e implemented with PI only it is stable but I feel it is a bit slow. For thi
s controller I have a changing input (fast change) and a constant Vout. I wo
nder if linearation may help. I have a linearized model i'm going to try nex
t if time is allowed. I have to be very careful not to over voltage the outp
ut (clamping the duty) so my mosfet won't blow up...
【在 c*******r 的大作中提到】
: same as analog control, PID compensation is enough.
: note, make conservative design to stable the loop at all load conditions
: since control to output transfer function of boost changes with loads.
:
: is
: brutal
|
E*****a
发帖数: 757 | 4 boost cannot be fast due to the RHP pole compensation
if you use current mode, changing input is no problem
you can do an overvoltage protection, when output is over 15% higher,
disable switching. What mean clamping the duty?
on
thi
wo
nex
outp
【在 l***g 的大作中提到】
: thanks
: right it's non linear so the dynamic response would be non linear. I have on
: e implemented with PI only it is stable but I feel it is a bit slow. For thi
: s controller I have a changing input (fast change) and a constant Vout. I wo
: nder if linearation may help. I have a linearized model i'm going to try nex
: t if time is allowed. I have to be very careful not to over voltage the outp
: ut (clamping the duty) so my mosfet won't blow up...
|
l***g
发帖数: 1035 | 5 by clamping i meant Vout = 1/(1-D)Vin, I set a Dmax so that Vout won't excee
d the Vmax under concervative Vin.
【在 E*****a 的大作中提到】
: boost cannot be fast due to the RHP pole compensation
: if you use current mode, changing input is no problem
: you can do an overvoltage protection, when output is over 15% higher,
: disable switching. What mean clamping the duty?
:
: on
: thi
: wo
: nex
: outp
|
g****t
发帖数: 31659 | 6 把输入的变化率设成常数,然后就一切都可以大致算出来.
换句话说,Vin=a+bt.
boost计算往往假设Vin变化很慢.
按此算出来的PI补偿不一定够好.
excee
【在 l***g 的大作中提到】
: by clamping i meant Vout = 1/(1-D)Vin, I set a Dmax so that Vout won't excee
: d the Vmax under concervative Vin.
|
c******s
发帖数: 197 | 7 average current mode will be good choice |
