Global Optimal Energy Management Strategy Research for a Plug-In Series-Parallel Hybrid Electric Bus by Using Dynamic Programming

Table 2

Working modes when SOC<SOC_low.

The required speed and torque areas of the final drive in Figure 8	PHEB possible working mode	Remarks
1	Series mode	Engine/ISG works in maximum power point
2	Engine-only mode	Engine only drives the PHEB
3	Engine-ISG parallel mode	Engine drives the PHEB, and the ISG generates as much electric energy as possible to charge the battery