Hyundai Ioniq (AE): Hybrid Motor Control System / Description and operation
In a hybrid electric vehicle, HCU (an upper level controller), LDC (power converter), and inverter are integrated in the HPCU. HPCU is located on the left side of the engine compartment.
The inverter provides high-voltage AC current to the two motors (drive motor and HSG) and controls them optimally based on the driving conditions through communication with the HCU.
The inverter also changes the DC current from the high-voltage battery into 3-phase AC current that is required for the operation of the motor.
The inverter receives the torque commend from the HCU to control the motor. The motor acts as a generator during deceleration and braking and changes the 3-phase AC current into the DC current to charge the battery.
Inverter is also called a motor control unit (MCU) from the perspective of a controller.

Component location1. HPCU (Hybrid Power Control Unit)(LDC+MCU+HCU+Reservoir)2. Hybrid drive motor3. Hybrid starter generator (HSG)4. Electrical radiator5.
Other information:
Inspection1.Turn the ignition switch ON.2.Connect the GDS.3.Emit intensive light toward the photo sensor using a lamp, and check the output voltage change.4.The voltage will rise with higher intensive light and reduce with lower intensive light.1. Auto light signal2.
Removal1.Disconnect the negative (-) battery terminal.2.Remove the steering wheel assembly.(Refer to Steering System -"Steering Wheel")3.Remove the steering back cover (A).4.Remove the steering remote control connector (A).5.Remove the steering remote control (A), after loosening the screws.