TY - JOUR
T1 - Effects of electric circulation on the energy efficiency of the power split e-CVT hybrid systems
AU - Chung, Cheng Ta
AU - Wu, Chien Hsun
AU - Hung, Yi Hsuan
N1 - Funding Information:
Funding: The authors would like to thank the Ministry of Science and Technology of the Republic of China, Taiwan, for financial support for this research under Contract No. MOST 105-2221-E-150-059, 106-EPA-F-009-001, and 107-2221-E-150-036; and thanks to the Industrial Technology Research Institute (ITRI) project for advanced vehicle control.
Publisher Copyright:
© 2018 by the authors. Licensee MDPI, Basel, Switzerland.
PY - 2018/9
Y1 - 2018/9
N2 - This paper aims at investigating the fundamental characteristics of energy efficiency for power split electronic-continuously-variable-transmission (e-CVT) hybrid systems under the operation of electric circulation, i.e., circulating part of the engine power through the generator and motor in form of electric energy to improve system efficiency as well as perform the continuously-variable-transmission (CVT) functionality. The relations of kinematics and energy conservation for each power component are constructed and analyzed to classify how the operating points of the engine in term of torque and rotational speed may vary under different degrees of electric circulation indicated by a parameter called ratio of circulating power. Thereby, power split e-CVT hybrid systems can be classified into three types: upward circulation, downward circulation, and neutral circulation. Accordingly, two power split e-CVT hybrid systems, one of input split type and the other of output split type, are selected to be analyzed regarding their operating characteristics and simulated on their performances of energy efficiency. As a result, the former is a type of downward circulation in favor of driving at low speed and high driving load, while the latter is a type of upward circulation with an advantage of driving at high speed and low driving load. Thereby, applying this analysis to investigate the effects of electric circulation on power split e-CVT systems may help the developers implement suitable energy management and control strategy in accordance with their corresponding operating characteristics of energy efficiency.
AB - This paper aims at investigating the fundamental characteristics of energy efficiency for power split electronic-continuously-variable-transmission (e-CVT) hybrid systems under the operation of electric circulation, i.e., circulating part of the engine power through the generator and motor in form of electric energy to improve system efficiency as well as perform the continuously-variable-transmission (CVT) functionality. The relations of kinematics and energy conservation for each power component are constructed and analyzed to classify how the operating points of the engine in term of torque and rotational speed may vary under different degrees of electric circulation indicated by a parameter called ratio of circulating power. Thereby, power split e-CVT hybrid systems can be classified into three types: upward circulation, downward circulation, and neutral circulation. Accordingly, two power split e-CVT hybrid systems, one of input split type and the other of output split type, are selected to be analyzed regarding their operating characteristics and simulated on their performances of energy efficiency. As a result, the former is a type of downward circulation in favor of driving at low speed and high driving load, while the latter is a type of upward circulation with an advantage of driving at high speed and low driving load. Thereby, applying this analysis to investigate the effects of electric circulation on power split e-CVT systems may help the developers implement suitable energy management and control strategy in accordance with their corresponding operating characteristics of energy efficiency.
KW - Electric circulation
KW - Energy management
KW - Hybrid system
KW - Power split e-CVT
UR - http://www.scopus.com/inward/record.url?scp=85054003234&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85054003234&partnerID=8YFLogxK
UR - http://www.mdpi.com/1996-1073/11/9/2342
UR - http://www.mendeley.com/research/effects-electric-circulation-energy-efficiency-power-split-ecvt-hybrid-systems
U2 - 10.3390/en11092342
DO - 10.3390/en11092342
M3 - Article
AN - SCOPUS:85054003234
VL - 11
JO - Energies
JF - Energies
SN - 1996-1073
IS - 9
M1 - 2342
ER -
