Theory Of Operation - Motor A And Motor B

WARNING: This page is about a different variant/trim than selected.

The Motor Generator Unit (MGU) or Motor "A" is a belt driven 3-phase electric motor that provides charging for the HV battery. This motor replaces the conventional starter on this vehicle. The Hybrid Control Processor (HCP) monitors current phase, resolver, and MGU temperature sensor inputs. The HCP is internal to the Power Inverter Module (PIM). If a temperature sensor, motor current phase, or resolver is faulty, the MGU must be replaced.

The Transmission on this vehicle also contains a 3-phase electric motor, or "Motor B" inside of the transmission. This motor is used for propulsion and regeneration charging during braking. In extreme cold ambient temperatures, (-10°C, 14°F) this motor is used to aid the P1f motor for engine starting. The HCP also monitors Motor B current phase, resolver, and electric motor temperature sensor inputs. If a motor current phase, or resolver is faulty, the transmission must be replaced. The electric motor temperature is serviced separately.

The 3-phase AC induction motors are comprised of the stator and rotor. During operation, a current is applied through the stator, which induces a magnetic field and leads to the rotation of the rotor. The rotational speed of the shaft and the applied torque is dependent on the operating frequency and the number of pole pairs in the motor's windings.

The motor position sensor (resolver) is monitored by the Motor Control Processor (MCP) located in the Power Inverter Module (PIM). The MCP monitors the angular position, speed and direction of the motor generator based upon the signals of the resolver type position sensor. The position sensor, or resolver, contains a drive coil, two driven coils, and an irregular shaped metallic rotor. The metallic rotor is attached to the shaft of the motor generator. At ignition ON, the MCP outputs a fixed excitation signal to the drive coil. The drive coil excitation signal creates a magnetic field surrounding the two driven coils and the irregular shaped rotor. The MCP then monitors the two driven coil circuits for a return signal. The position of the irregular metallic rotor causes the magnetically induced return signals of the driven coils to vary in size and shape. A comparison of the two driven coil signals allows the MCP to determine the exact position, speed and direction of the motor generator. The motor Resolver is integrated into the Motors and is not serviceable.

SYSTEM DESCRIPTION AND OPERATION: The PHEV system is designed for the electric motor to be used for vehicle propulsion when the High Voltage (HV) battery is above a minimum charge level. When the HV battery charge level is below a calibrated threshold, the engine is started. The engine can be connected to the vehicle driveline through the electric motor in the transmission to propel the vehicle if needed. It also drives the electric motor on the front of the engine with the serpentine belt to charge the HV battery. This vehicle consists of the following motor configuration:

The Motor Generator Unit (MGU), or Motor "A" is a belt driven 3-phase electric motor at the front of the engine (P1f). The P1f motor is used in place of a conventional starter motor to crank the engine during starting. When the engine is running the P1f motor provides charging for the HV battery. The Hybrid Control Processor (HCP) monitors current phase, resolver, and MGU temperature sensor inputs.
The Transmission on this vehicle also contains a 3-phase electric motor, or "Motor B" inside of the transmission (P2). This motor is used for propulsion and regeneration charging during braking. In extreme cold ambient temperatures, (-10°C, 14°F) this motor is used to aid the P1f motor for engine starting. The HCP also monitors Motor B current phase, resolver, and electric motor temperature sensor inputs. If a motor current phase, or resolver is faulty, the transmission must be replaced. The electric motor temperature sensor is serviced separately.

The motor position sensor (Resolver) is monitored by the Motor Control Processor (MCP). The MCP monitors the angular position, speed and direction of the motor generator based upon the signals of the resolver type position sensor. The position sensor, or resolver, contains a drive coil, two driven coils, and an irregular shaped metallic rotor. The metallic rotor is attached to the shaft of the motor generator. At ignition ON, the MCP outputs a fixed excitation signal to the drive coil. The drive coil excitation signal creates a magnetic field surrounding the two driven coils and the irregular shaped rotor. The MCP then monitors the two driven coil circuits for a return signal. The position of the irregular metallic rotor causes the magnetically induced return signals of the driven coils to vary in size and shape. A comparison of the two driven coils signals allows the MCP to determine the exact position, speed and direction of the motor generator. The motor Resolver is integrated into the motor and is not serviceable.