I am trying to design a High Power DC/DC Boost Converter that can supply a desired current waveform. As the inductor is in the input side of DC/DC converter peak mode current control cannot replicate the output current. Are there any specific control techniques that can be employed to control the output current ?
I'm not sure how powerful your converter is. Are we talking of Watts or kiloWatts?
Generally, there are power limits to the topology one is using. For high power applications, one would use a full bridge push-pull configuration with transformer isolation, rather than a single transistor/diode/inductor topology.
As for the control, one would use a fast processor, typically a DSP, with a PID control loop. This should be sufficient for most applications. If you want to control the current, you should at least have a fast current sensor and current control loop in your program.
The Inductor / transformer should be adequately rated to easily handle the maximum current and several parralel connected filter capacitors are required on the output side.
Try this page to get an idea of which power range and topology you need for your application. http://schmidt-walter.eit.h-da.de/smps_e/smps_e.html
Thanks David, for your response.
The power rating of the converter is about 1.5kW and I am using IGBT switches for regulating the inductor current. I am actually using this converter to interface an ultracapacitor of 16V,100F to a DC link of 48V. I want the high frequency part of the step change in load to flow from the ultracapacitor and steady state part from the battery connected in the DC link. In the simulation model I tried to design, I cannot replicate the required current (which is changing with time) in the output side of the converter. The conventional technique of peak current control doesn't seem to be working here as this technique controls the inductor current on the input side.
I have however tried the same peak current control method on a buck converter and it seems to be working fine as the inductor is in the output side.
One solution, I have come up with is to use an intermediate capacitor where I can boost the voltage to 60V from the ultracapacitor and use the voltage control loop for the boost converter and then use a buck converter to supply the required current to the DC link using peak current control. By this method is unfeasible economically and has higher losses. So, I need a technique where I can use a boost converter as a current replicator.
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