I want to design a buck converter to charge a battery(12v), i have 24v voltage bus as input. i have to do it in matlab. how can i do it.
and also how i can have the control loop(closed loop for D(duty ratio). for charging the battery initially constant current should be achieved,den constant voltage has to be achieved. how can i get these conditions without using dsp or fuzzy controller. how to do it in matlab any references plz.
You can realize the control by simple PI controller or P type controller. One way to implement it by using two parallel control loop one for current and other for voltage. Depending upon the error from set point one of these would be active. For example at start current loop to be active (as battery impedance would be low and lower supply voltage you will start drawing desired current), and once battery is sufficiently charged battery impedance would increase and voltage loop becomes active, as you need to generate more voltage to maintain the current.
my doubt is how to simulate it in matlab, generelly in buck converter we have the resistance as a load but here we have the battery. so how can we implement the simulation in matlab(without using the battery model available). and to have the set points for constant current how can we get them from the specification of battery.
You can also use PSpice SLPS for this simulation. PSpice SLPS allows you to simulate part of circuit in matlab and PSpice offers battery model. This way you can place your controller in MATLAB and use ready to use battery model available in PSpice. This will save you from modeling your battery in Matlab.
Hey I was just wondering if you got this to work and how ?. I`m currently trying to implement it in simulink but having no joy can not get teh current to stablize when in the constant voltage stage.