Power Analysis of Epicyclic Transmissions Based on Constraints

2012 ◽  
Vol 4 (4) ◽  
Author(s):  
Chao Chen
Keyword(s):  
Power Analysis ◽  
Power Flow ◽  
Flow Analysis ◽  
Total Efficiency ◽  
Power Losses ◽  
Virtual Power ◽  
Contour Maps ◽  
System A ◽  
Epicyclic Gear ◽  
Electrical Vehicles

Epicyclic gear transmissions have many applications. The internal power flow of epicyclic systems is highly related to the power loss of the system. A systematic method and generic formulas based on kinematic constraints are derived to conduct the power flow analysis, by means of Lagrange multipliers and newly introduced selection matrices. The method and formulas can be readily applied to complicated epicyclic systems. The graphic representation of the power flow of two examples verifies the balance of the power flow and virtual power flow. In the example of the Dual-E powertrain for hybrid electrical vehicles, an estimation of the total efficiency is derived. The pattern of contour maps of the total efficiency indicates the operational ranges of the powertrain with relatively low power losses.

Power Flow Analysis of Compound Epicyclic Gear Transmission: Simpson Gear Train

2011 ◽  
Vol 133 (9) ◽  
Author(s):  
Chao Chen
Keyword(s):  
Power Flow ◽  
Flow Analysis ◽  
Gear Transmission ◽  
Gear Train ◽  
Total Efficiency ◽  
Virtual Power ◽  
Speed Reduction ◽  
Power Flow Analysis ◽  
Epicyclic Gear ◽  
The Individual

An analytical expression for the total efficiency of the Simpson gear train is derived using virtual power analysis. This expression is consistent with intuition when the total efficiency is 100%. Power flow analysis shows that there are no internal power circulation and amplification in the Simpson gear train. Analysis based on the derived efficiency formula shows that the total efficiency of the Simpson gear transmission is more sensitive to the individual gear efficiencies when the speed reduction is higher.

Virtual-Power Flow and Mechanical Gear-Mesh Power Losses of Epicyclic Gear Trains

2006 ◽  
Vol 129 (1) ◽  
pp. 107-113 ◽  
Author(s):  
Chao Chen ◽  
Jorge Angeles
Keyword(s):  
Power Loss ◽  
Power Flow ◽  
Gear Train ◽  
Power Losses ◽  
Virtual Power ◽  
Noninertial Frame ◽  
Gear Mesh ◽  
Epicyclic Gear ◽  
Gear Trains ◽  
The Subject

The concept of virtual power is first defined as the power measured, in a noninertial frame, in an epicyclic gear train. We then introduce the concept of virtual-power ratio, an invariant related to the power loss in an epicyclic system. It is shown that virtual-power flow and balance exist in an epicyclic gear train, based on which a novel algorithm to compute the gear-mesh powerloss and the train efficiency is formulated. This algorithm is general enough to be applied to any given epicyclic gear train. Our results are compared with previous work on the subject.

Nomographs for Kinematics, Statics and Power Flow Analysis of Epicyclic Gear Trains

2009 ◽  
Author(s):  
Essam L. Esmail ◽  
Hamed A. Hussen
Keyword(s):  
Electric Motor ◽  
Power Flow ◽  
Automatic Transmission ◽  
Flow Analysis ◽  
Gear Train ◽  
Innovative Design ◽  
Epicyclic Gear ◽  
Power Split ◽  
Gear Trains ◽  
Flow Through

A new methodology for constructing multi-axes nomographs is developed. Using this methodology, a unified general formulation for computing velocities and torques of any epicyclic-type transmission train is presented. To demonstrate and apply the new technique, Ravigneaux automatic transmission is used to show how the velocities, the torques and the power flow through the train can be simultaneously visualized on a single nomograph. The present methodology is judged to be more efficient than other methods and than the three-ax nomograph methodology. Using this methodology an innovative design of two-input transmission with only one electric motor/generator (MG) and without any rotating clutches is presented. The proposed design provides some of the benefits and flexibility of a power-split design by using the conventionally available Ravigneaux gear train in a simpler mechanical layout which makes the design compact, mechanically simple, and operationally flexible.

Torque and Power-Flow Analyses of Two Input Epicyclic-Type Transmission Trains

2008 ◽  
Author(s):  
Essam L. Esmail ◽  
Shaker S. Hassan
Keyword(s):  
Power Flow ◽  
Flow Analysis ◽  
Gear Train ◽  
Root Cause ◽  
Transmission Design ◽  
Epicyclic Gear ◽  
Systematic Methodology ◽  
Hybrid Transmission ◽  
The Given ◽  
Input Torque

This study contributes to the development of a systematic methodology for the torque and power flow analyses of two-input epicyclic gear mechanisms (EGMs) with or without reaction link, based upon the concept of fundamental circuit. The studies on power flow analysis of EGMs are mostly done in the context of efficiency formulations. In the opinion of the authors, the design process of two-input mechanism involves not only finding the configuration that provides the correct velocity ratios, but also meets other dynamic and kinematic requirements and ensures that the two inputs have a mutually constructive nature. To demonstrate the analysis, a new motor/generator integrated hybrid transmission design is used to show how the torque acting on each link of an epicyclic gear train (EGT) can be systematically solved in terms of input torque(s) and/or controlled output torque. This paper presents a unification of kinematic and torque balance approaches for the analysis of two-input epicyclic-type transmission trains. The results presented are meant to deepen the knowledge as to how and why a two-input epicyclic-type transmission should operate in a certain way under the given conditions. In the process, this paper explores the theoretical bases of operation of the Toyota Hybrid System (THS) and the root cause of some confusion in the field of EGTs.

Complete Efficiency Analysis of Epicyclic Gear Train With Two Degrees of Freedom

2012 ◽  
Vol 134 (7) ◽  
Author(s):  
Kieran Davies ◽  
Chao Chen ◽  
Bernard K. Chen
Keyword(s):  
Optimal Design ◽  
Power Flow ◽  
Degrees Of Freedom ◽  
Efficiency Analysis ◽  
Operating Conditions ◽  
Gear Train ◽  
Virtual Power ◽  
Two Degrees Of Freedom ◽  
Epicyclic Gear ◽  
Gear Trains

Epicyclic gear trains (EGTs) are important mechanical transmissions with many applications. For optimal design and operation of these gear trains, it is necessary to obtain complete efficiency maps of such transmissions. The efficiency of a two degrees of freedom (two-dof) EGT is derived based on the internal power flow and virtual power flow patterns. Expressions for the efficiencies in different operating conditions are obtained and verified by three special conditions.

An Approach to Power-Flow and Static Force Analysis in Multi-Input Multi-Output Epicyclic-Type Transmission Trains

2009 ◽  
Vol 132 (1) ◽  
Author(s):  
Essam L. Esmail ◽  
Shaker S. Hassan
Keyword(s):  
Power Flow ◽  
Flow Analysis ◽  
Gear Train ◽  
Root Cause ◽  
Transmission Design ◽  
Epicyclic Gear ◽  
Systematic Methodology ◽  
Hybrid Transmission ◽  
The Given ◽  
Input Torque

This study contributes to the development of a systematic methodology for the torque and power-flow analyses of multi-input multi-output (MIMO) epicyclic gear mechanisms (EGMs) with or without reaction link based on the concept of fundamental circuit. The studies on power-flow analysis of EGMs are mostly done in the context of efficiency formulations. In the opinion of the authors, the design process of the MIMO mechanism involves not only finding the configuration that provides the correct velocity ratios but also meeting other kinematic requirements and ensuring that the two inputs have a mutually constructive nature. To demonstrate the analysis, a new motor/generator integrated hybrid transmission design is used to show how the torque acting on each link of an epicyclic gear train (EGT) can be systematically solved in terms of input torque(s) and/or controlled output torque. This paper presents a unification of kinematic and torque balance approaches for the analysis of MIMO epicyclic-type transmission trains. The results presented are meant to deepen the knowledge as to how and why a MIMO epicyclic-type transmission should operate in a certain way under the given conditions. In the process, this paper explores the theoretical bases of operation of the Toyota Hybrid System and the root cause of some confusion in the field of EGTs.

scholarly journals Power Losses and Bus Voltage in Transmission Lines of a 28 Bus System

2020 ◽  
Vol 8 (5) ◽  
pp. 5675-5684
Keyword(s):  
Power System ◽  
Transmission Lines ◽  
Power Flow ◽  
Reactive Power ◽  
Flow Analysis ◽  
Power Losses ◽  
Integrated Network ◽  
Line Outages ◽  
Flexible Alternating Current Transmission ◽  
Bus Voltage

Inadequate supply of power is increasing day by day and causing a lot of problems and affecting various sectors of the country. This work involves the power analysis on the 28-bus network of the Nigeria 330kV integrated power system. The network consists of twenty-eight (28) buses, nine (9) generation stations, and fifty-two (52) transmission lines. Newton-Raphson (N-R) method of power flow analysis was carried out on the network using the relevant data. This analysis was carried out using PSS®E to determine bus voltages, real and reactive power losses of the integrated network. The work also involves carrying out line outages on various parts of the network to determine the effects on power losses and bus voltages. The results show that the following buses were not in line with the statutory limit of 0.95≤Vi≤1.05: bus 13 (New-Heaven), bus 14 (Onitsha), bus 16 (Gombe), bus 19 (Jos), bus 22 (Kano). Bus 16 was observed to not satisfy the limit during the analysis going as low as 0.7602p.u. in one of the line outages (Makurdi-Mambila off). The total losses was also determined and the highest power loss was observed when Makurdi-Mambila line was taken out of service (142.54MW, 1072.16MVAR) and the lowest loss was observed when the double transmission line between Benin-Sapele were both taken out of service(105.0MW, 830.50MVAR). This result concludes that the Nigeria network still needs to undergo changes to ensure sustainable and reliable power system. Compensation is recommended on the above stated weak buses using Flexible Alternating Current Transmission System (FACTS).

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