Iam interested to integrate an energy storage at Dc link of an inverter, by using a dc-dc converter. Can any one help me how to control the power flow in bi-directional of that converter.
there are many topologies that can permit you attain your objective, if differs generally according to the nature of your storage, if you use batteries, you can connect them directly to the dc bus but you admit that the dc voltage will be that of the batteries (variable with the batteries current but slowly). else if you have to regulate the dc voltage to some desired dc value your have to connect the storage elements to the dc bus through a converter (let's say a boost converter).
If you storage is a voltage source (the most simple is a battery or a supercap) whose voltage is always higher than the inverter bus, a phase leg (two switch) connected to the storage and an inductor let you control power flow between the Dc source and the inverter bus simply controlling the current in the inductor. If you need power from storage to inverter, the upper switch will act as as step down and inductor current will be positive; if power flow is from inverter to storage, the lower switch will step up and inductor current will be negative. Close the loop on the inductor current using average current mode with voltage limit when reference current is negative.
Let me know if you storage is different
Mr.Guido can you please provide any reference supporting to your discussion to me.
Mr Anil
I put in the attached document two schematic: the first applies when you have a dc storage always higher than the inverter bus, the second can be used without restriction. I also added some hints regarding control and PWM generation. Control is the same for both solutions, except for the modulator which is a little bit more complex for the second solution because you have four switches: in this case you will need two trtiangular carries instead of one.
Sorry M Anil
Delete the second error node before the currente regulator....!
Thank u Mr.Botto, can you provide any suitable reference for better understanding.
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