Control Strategy for Double Motor Electric Vehicle Ⅱ

2. Powertrain structure and parameters
  The powertrain system is composed of front motor, rear motor, and battery. The vehicle structure of PHEV is shown in Fig.1. Parameter values and specifications for the PHEV model are provided in Table 1. HCU (Hybrid Control Unit) can control front motor and rear motor to realize the all-wheel drive (AWD) mode, front- wheel drive (FWD) mode, and rear-wheel drive (RWD) mode.

3. Vehicle control strategy
3.1 Battery Energy Management Strategy
The idea of battery energy management strategy makes full use of battery energy for economy.
The instantaneous optimization target function is described in equation (1).

  where, WD P is the driver wheel demand power, b P is the battery consumption power , b U is the battery voltage, b I is the battery current, FM P is the front motor power , FM η is the front motor efficiency, FM T is the front motor torque, FM N is the front motor speed, RM P is the rear motor power , RM η is the rear motor efficiency, RM T is the rear motor torque, RM N is the rear motor speed.