Study on the Torque Distribution Control Method of P1-P2 Parallel Hybrid System

In this paper, the control logic of a parallel hybrid system with a P1-P2 motor was studied. In determining engine on/off timing, the engine and motor torque distribution, the P1-P2 motor torque distribution, and the SOC management control are necessary in controlling the P1-P2 hybrid system. Backward simulation methods were then used in developing such a hybrid system control logic. Since the backward simulation method derives theoretical optimal operating points, it presents a real-time control logic configuration method that follows the backward simulation results. A rule-based control logic was constructed, and a control map was generated based on the results of the backward simulation. Next, a forward simulator was constructed to verify the control logic. Based on the fuel efficiency analysis, it was confirmed that the length of the backward simulation showed an error of within 8.18 %, compared to the previous one. It is verified that the SOC path is similar, and that the SOC management control logic converges to the intermediate SOC level, even when the analysis starts under SOC over-discharge and overcharge conditions.