Power Flow Control in Series Hybrid

In the series hybrid system there are four operating modes based on the power flow:

• •  Mode 1: During startup (Figure 1a), normal driving or acceleration of the series HEV, both the ICE and battery deliver electric energy to the power converter which then drives the electric motor and hence the wheels via transmission.

•  Mode 2: At light load (Figure 1b), the ICE output is greater than that required to drive the wheels. Hence, a fraction of the generated electrical energy is used to charge the battery. The charging of the batter takes place till the battery capacity reaches a proper level.

•  Mode 3: During braking or deceleration (Figure 1c), the electric motor acts as a generator, which converts the kinetic energy of the wheels into electricity and this, is used to charge the battery.

•  Mode 4: The battery can also be charged by the ICE via the generator even when the vehicle comes to a complete stop (Figure 1d).

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