Based on the degree of mixing in the hybrid system, hybrid systems can also be divided into the following four categories:
1. Micro hybrid power system
Strictly speaking, this type of micro-hybrid system vehicle is not a true hybrid vehicle because its electric motor does not provide continuous power for the vehicle's movement.
2. Mild hybrid power system
In addition to controlling the engine's start and stop with a generator, a mild hybrid system can also: (1) absorb some energy during deceleration and braking; (2) maintain a constant engine speed during driving, allowing the energy generated by the engine to be adjusted between the driving demand of the wheels and the charging demand of the generator. The hybridization ratio of a mild hybrid system is generally below 20%.
3. Medium hybrid power system
The mid-hybrid system uses a high-voltage electric motor. In addition, the mid-hybrid system adds another function: when the car is accelerating or under heavy load, the electric motor can assist in driving the wheels, thus compensating for the insufficient power output of the engine and improving the overall vehicle performance. This system has a high degree of hybridization, reaching around 30%, and the technology is mature and widely used.
4. Full hybrid power system
Toyota's Prius and the future Estima are both full hybrid systems. This system uses a 272-650V high-voltage starter motor, resulting in a higher degree of hybridization. Compared to mid-hybrid systems, full hybrid systems can achieve or even exceed 50% hybridization. Technological advancements will make full hybrid systems the main direction of hybrid technology development.
