The principle of hybrid electric buses can be summarized as follows:
1. Energy Conversion: The hybrid power system combines two power sources, an internal combustion engine and an electric motor. Internal combustion engines generate mechanical energy through fuel combustion to drive vehicles. The electric motor converts the electrical energy provided by the battery pack into mechanical energy to assist or independently drive the vehicle. Under different driving conditions, the system can intelligently switch or simultaneously use internal combustion engines and electric motors to achieve efficient energy conversion and utilization.
2. Energy storage: The battery pack, as one of the core components of the hybrid system, is responsible for storing electrical energy and providing power to the electric motor. Modern hybrid buses typically use lithium-ion batteries with high energy density and high power output to ensure sufficient range and power output. When the vehicle brakes or decelerates, the braking energy recovery system converts kinetic energy into electrical energy and stores it in the battery pack, further improving energy utilization efficiency.
3. Energy control: The hybrid system achieves intelligent energy management through advanced control systems. The control system will adjust the working modes of the internal combustion engine and electric motor in real time based on the vehicle's driving conditions, the driver's operating intentions, and the battery pack's state of charge. For example, in situations where a large power output is required for vehicle start-up, acceleration, or climbing, the internal combustion engine and electric motor will work simultaneously to provide sufficient power. When the vehicle is traveling at a constant speed or decelerating, the system may choose to use only the electric motor or internal combustion engine to work independently in order to reduce energy consumption. The control system will also optimize the operating points of the internal combustion engine and electric motor, ensuring that they always operate within the optimal efficiency range, thereby further improving the fuel economy and emission performance of the entire vehicle.