How to Limit Current Draw in Single Phase MMC With 4 Half-Bridge IGBTs Heating Up?

   Hello Respected Seniors!
 i am working with modular multilevel converter(MMC). i have to go with single phase MMC. i have considered just 4 half bridges i.e two bridges in upper arm and two bridges in lower arm. when i apply power supply to the circuit it draws current from power supply i.e upto 5A or so on.
 i have attached the circuit pictures for understanding my point of view.
The igbts marked with red color are of upper arm and igbts marked with blue color are of lower arm.
 the igbts 1,2,3 and 4 are get heated so much that the temperature reaches 105 degree centigrade. for lowering the temperature i used heat sinkers but still the temperature is rising contentiously.

so my question is what i have to do so that the circuit current is limited. Kindly help
will be thankful and obliged . 

Hi Ishfaq-We will do our best to help, but there is not enough information in the picture and the general description.  Can you post a schematic and/or additional detailed description of the circuit?-Rick