①Compared with traditional cars, since the internal combustion engine always works in the best conditions, the fuel consumption is very low.
②The internal combustion engine mainly works near the best operating point, with sufficient combustion and clean exhaust gas; no idle speed at start (idle stop).
③ No external charging system is required, and problems such as the driving range and infrastructure of a single charge are solved.
④ The miniaturization of the battery pack makes the cost and weight lower than that of electric vehicles.
⑤The power of the engine and the electric motor can complement each other; it can be driven by the electric motor at low speed.
Under the current technical level and application conditions, hybrid electric vehicles are the most industrialized and marketable models of electric vehicles. Hybrid electric vehicles use internal combustion engine and electric motor as the hybrid power source. It not only has the advantages of fuel engine power, fast response and long working time, but also has the advantages of non-pollution and low noise of the electric motor, which achieves the best match between engine and electric motor.