Excavator mainly works in the field, with short and complex working cycle, excessive load and frequent overload, high dynamic response requirements, complex control algorithm, control strategy and maneuverability. Therefore, parameter optimization and matching, control strategy, energy recovery technology and reliability and controllability research are the key and difficult points of excavator hybrid technology development and application in the future.
1. Performance optimization and matching of special components and dynamic parameters of hybrid excavator system
The immature technologies such as engine structure and ignition mode, start / stop performance of auxiliary motor, specific energy, specific power of storage device, fast discharge performance and cycle number restrict the development of hybrid technology. The matching of dynamic parameters and the determination of the best mixing degree play a key role in energy utilization.
2. Control strategy and algorithm of hybrid excavator system
The auxiliary power unit composed of motor / generator, battery and capacitor is added in the hybrid power system, which makes the energy transfer and conversion more complex and energy loss increased. Energy management has an important impact on the fuel economy of diesel engine and the dynamic characteristics of the whole hybrid power system. The control algorithm will affect the control performance of torque and speed.
3. Energy recovery system of hybrid hydraulic excavator
The recovered energy includes the kinetic energy of turntable braking, the potential energy of boom and stick descending, and the recovery and driving are different systems, so it is of great significance to study the energy recovery system suitable for its own working conditions.
4. Reliability of hybrid hydraulic excavator
The working current of the energy storage device is large and the peak power is high, so it is necessary to carry out comprehensive design and reliability test of the energy storage system.
5. Handling of hybrid excavator
An important evaluation index of excavator performance is good controllability. The connection mode between engine and auxiliary power unit in hybrid system makes the control more complex, which affects the structure layout and controllability.
