The single-shaft parallel hybrid powertrain with the automatic mechanical transmission(AMT)is an efficient hybrid driving system in the hybrid electric bus(HEB),while the electromechanical coupling driving control bec...The single-shaft parallel hybrid powertrain with the automatic mechanical transmission(AMT)is an efficient hybrid driving system in the hybrid electric bus(HEB),while the electromechanical coupling driving control becomes a complicated question to find a transient optimal control method to distribute the power between the engine and the electric machine(EM).This paper proposes an innovative control method to deal with the complicated transient coupling driving process of the electromechanical coupling driving system,considering the accelerating condition and the cruising condition mostly in the city driving cycle of HEB.The EM might be operated at driving mode or generating mode to assist the diesel engine to work in its high-efficiency area.Therefore,the adaptive torque tracking controller has been brought forward to ensure that the EM implements the demand torque as well as compensate the torque fluctuation of diesel engine.The d?q axis mathematical model and back stepping method are employed to deduce the adaptive controller and its adaptive laws.Simulation results demonstrate that the proposed control scheme can make the output torque of two power sources respond rapidly to the demand torque from the powertrain in the given driving condition.The proposed method could be adopted in the real control of HEB to improve the efficiency of the hybrid driving system.展开更多
In our daily lives,low-frequency kinetic energy primarily manifests as vibrations.However,effective harnessing of lowfrequency kinetic energy remains a formidable challenge.This paper proposes a rope-driven rotor that...In our daily lives,low-frequency kinetic energy primarily manifests as vibrations.However,effective harnessing of lowfrequency kinetic energy remains a formidable challenge.This paper proposes a rope-driven rotor that rotates around an axis and consists of an ultra-high-molecular-weight polyethylene(UHMWPE)wire wrapped around a metal shaft.The rotor can convert ultra-low frequency vibration/linear motion into rapid rotation by pressing the top at low frequencies and driving the rope for a quick release.The harvester can generate up to 36.25 m W power using a 0.1-mm-diameter UHMWPE wire as the rotor when periodically pressed down to 20 mm at a frequency of 1 Hz.A simple power generation floor is assembled,generating 28.58-m W power with a matching load at a frequency of 1.5 Hz.Moreover,the harvester can increase the charging voltage of a 0.47-F supercapacitor from 0 to 6.8 V within 10 min.In addition,the harvester can harvest energy through a light finger press motion,and the energy obtained can also support the continuous operation of multiple electronic devices concurrently.This study introduces an effective method for harvesting ultra-low frequency energy and has great prospects in the field of power generation floor and human movement energy harvesting.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.51275557)the National Science-technology Support Plan Projects of China(Grant No.2013BAG14B01)
文摘The single-shaft parallel hybrid powertrain with the automatic mechanical transmission(AMT)is an efficient hybrid driving system in the hybrid electric bus(HEB),while the electromechanical coupling driving control becomes a complicated question to find a transient optimal control method to distribute the power between the engine and the electric machine(EM).This paper proposes an innovative control method to deal with the complicated transient coupling driving process of the electromechanical coupling driving system,considering the accelerating condition and the cruising condition mostly in the city driving cycle of HEB.The EM might be operated at driving mode or generating mode to assist the diesel engine to work in its high-efficiency area.Therefore,the adaptive torque tracking controller has been brought forward to ensure that the EM implements the demand torque as well as compensate the torque fluctuation of diesel engine.The d?q axis mathematical model and back stepping method are employed to deduce the adaptive controller and its adaptive laws.Simulation results demonstrate that the proposed control scheme can make the output torque of two power sources respond rapidly to the demand torque from the powertrain in the given driving condition.The proposed method could be adopted in the real control of HEB to improve the efficiency of the hybrid driving system.
基金supported by the National Natural Science Foundation of China(Grant Nos.62171414,U2341210,52175554,and 52205608)the Fundamental Research Program of Shanxi Province(Grant Nos.20210302123059,and 20210302124610)+1 种基金the Hebei Province Central Guiding Local Science and Technology Development Fund Project(Grant No.236Z4901G)the National Defense Fundamental Research Project。
文摘In our daily lives,low-frequency kinetic energy primarily manifests as vibrations.However,effective harnessing of lowfrequency kinetic energy remains a formidable challenge.This paper proposes a rope-driven rotor that rotates around an axis and consists of an ultra-high-molecular-weight polyethylene(UHMWPE)wire wrapped around a metal shaft.The rotor can convert ultra-low frequency vibration/linear motion into rapid rotation by pressing the top at low frequencies and driving the rope for a quick release.The harvester can generate up to 36.25 m W power using a 0.1-mm-diameter UHMWPE wire as the rotor when periodically pressed down to 20 mm at a frequency of 1 Hz.A simple power generation floor is assembled,generating 28.58-m W power with a matching load at a frequency of 1.5 Hz.Moreover,the harvester can increase the charging voltage of a 0.47-F supercapacitor from 0 to 6.8 V within 10 min.In addition,the harvester can harvest energy through a light finger press motion,and the energy obtained can also support the continuous operation of multiple electronic devices concurrently.This study introduces an effective method for harvesting ultra-low frequency energy and has great prospects in the field of power generation floor and human movement energy harvesting.
