PHEV (P1+P3) power system solution
P1+P3 scheme, the low and medium speeds are driven by pure electric, and the engine directly drives the vehicle at high speeds; it is suitable for vehicles with high-speed driving conditions such as A-level models and SUVs, and the overall fuel consumption is about 2L/100km. The engine, generator/starter, and motor form a power unit through a power coupling device.
The Atkinson cycle engine is most suitable for PHEV. The engine dedicated to PHEV uses the Atkinson cycle with a minimum specific fuel consumption of 230g/kWh, and the ordinary engine has a minimum specific fuel consumption of 250g/kWh. With the Atkinson cycle, the fuel consumption is lower and the minimum specific fuel consumption is <230g/kWh. In the NEDC cycle of PHEV, 90% of the operating points are located in the high efficiency zone (<250g/kWh).
The calibration workload of the EMS system in PHEV is greater.
(1) Using a special Atkinson cycle engine, the software needs to be specially modified, and the calibration workload is larger;
(2) The starter is cancelled and the ISG motor is used to start the drive, and the control logic of the start process needs to be added;
(3) The ignition key is cancelled, and automatic start-stop control logic needs to be added;
(4) The electronic accelerator pedal is not connected to the ECU, but directly to the HCU, so the ECU needs to add PHEV-specific torque control logic;
(5) According to the CAN bus architecture and definition of the whole vehicle, special CAN communication content needs to be added;
(6) Special warm-up control logic needs to be added;
(7) It is necessary to increase the ignition control logic during the shutdown process;
(8) It is necessary to add control logic to prevent reverse rotation. Yu Shuhuai said that the calibration workload of the EMS system in PHEV has increased by about 50% compared with traditional vehicles.