I am trying to implement F.O.C for a PMSM machine with a custom made inverter board. The H-bridges are from Infineon (IFX007T) and they provide current sensing capabilities. The problem is, i need the current information from all three phases and the H-bridges provide this information only when the High side is active - so no negative/return current info.
If two of the H-bridges are High-Side active, then it is easy to calculate the third since the sum of their magnitude must be 0.
My question is: Is there a viable way to calculate/estimate other 2 phase currents when i can only measure 1 phase current. This can be a mathematical transformation exploiting the fact that its a 3 phase balanced system. Any other shunt-resistance like solution is also appreciated.
PS: I need the current info to compare it with the rotor flux angle provided from the rotary encoder to do a feedback control.