Inverter Charger architecture question

[SoulFreeze]

Hello all, I have a mastervolt charger inverter I'm trying to repair, as I have no schematics I decided to trace our some of the parts to figure out the general operation.
I managed to trace our a rough block diagram of the power stage, and I'm quite interested in the operation.

Here are my questions.
I noticed there seems to be no dedicated charging section in the circuit. After some googling I assume this is what they called a bidirectional power design. Would like to know if my assumption of the operation are right.
Given that there are no diodes. I am assuming the operation of the components served different purposes depending on whether it's charging or inverting.
My understanding is

When inverting:
-the low voltage side mosfets are in high frequency DC to AC switching
-The IGBTs act as active rectifiers and do the HV AC-DC conversion
-The last stage of IGBTs do the final sine wave low frequency DC to AC switching

When charging the reverse happens
The last stage IGBTs act as active rectifiets
The middle stage of IGBTs do the HV High freq switching into the transformer
Then the low side mosfets rectify the voltage to low voltage DC to charge the battery.

Is this correct?

Further more, there are 3 extra IGBTs circled, wired in kind of a differential pair (the ones facing each other), along with a large torroidal inductor on the HV DC positive rail.
What is the purpose of these components? I'm assuming it's related with regulating the HV DC rail? Is it for charging?

(Kindly note that due to the lack of proper schematics the circuit trace attempt might have significant errors, especially with low resistance components that may exist where I assumed they are just connected.)

Anyone willing to explain the operation further would be highly appreciated.

[SoulFreeze]

Hello all, I have a mastervolt charger inverter I'm trying to repair, as I have no schematics I decided to trace our some of the parts to figure out the general operation.
I managed to trace our a rough block diagram of the power stage, and I'm quite interested in the operation.

Here are my questions.
I noticed there seems to be no dedicated charging section in the circuit. After some googling I assume this is what they called a bidirectional power design. Would like to know if my assumption of the operation are right.
Given that there are no diodes. I am assuming the operation of the components served different purposes depending on whether it's charging or inverting.
My understanding is

When inverting:
-the low voltage side mosfets are in high frequency DC to AC switching
-The IGBTs act as active rectifiers and do the HV AC-DC conversion
-The last stage of IGBTs do the final sine wave low frequency DC to AC switching

When charging the reverse happens
The last stage IGBTs act as active rectifiets
The middle stage of IGBTs do the HV High freq switching into the transformer
Then the low side mosfets rectify the voltage to low voltage DC to charge the battery.

Is this correct?

Further more, there are 3 extra IGBTs circled, wired in kind of a differential pair (the ones facing each other), along with a large torroidal inductor on the HV DC positive rail.
What is the purpose of these components? I'm assuming it's related with regulating the HV DC rail? Is it for charging?

(Kindly note that due to the lack of proper schematics the circuit trace attempt might have significant errors, especially with low resistance components that may exist where I assumed they are just connected.)

Anyone willing to explain the operation further would be highly appreciated.

Made a mistake on the diagram, the torroid should be between the tranformer side fets, as shown