scholarly journals Losses and energy efficiency of drive motors and systems

2013 ◽  
Vol 20 (1) ◽  
pp. 3-10 ◽  
Author(s):  
Zygmunt Paszota
Keyword(s):  
Energy Efficiency ◽  
Power Flow ◽  
Objective Evaluation ◽  
Drive System ◽  
Motor Speed ◽  
Rotational Displacement ◽  
Operating Field ◽  
Useful Power ◽  
New Perspective ◽  
Drive Systems

Abstract Losses and energy efficiency of every drive motor must be presented as functions of physical quantities independent of losses in the motor. Such quantities are speed and load required by the machine or device driven by the motor, changing in the drive operating field. Speed and load of the motor decide of the instantaneous useful power of the motor and also in a differentiated way of kinds and values of losses occurring in the motor. However, losses and energy efficiency of the hydrostatic drive motors and systems are evaluated by researchers and manufacturers as functions of parameters depending on the losses. The basic cause of such situation is the traditional, commonly accepted but erroneous, view of the power flow in the drive motors and systems represented by the Sankey diagram of power decrease in the direction of power flow. It is necessary to replace the Sankey diagram by the proposed diagram of increase of power in the motor and in the drive system in the direction opposite to the direction of power flow. The proposed view of losses and energy efficiency should be applied to all types of motor and drive systems. The aim of this paper is showing the resulting problems of the above postulates, exemplified by operation of a rotational displacement motor in a hydrostatic drive system. In order to make possible objective evaluation of the energy behaviour of different motor and system solutions and sizes, the losses and energy efficiency should be described and compared as dependent on the motor speed coefficient ωM and load coefficient M changing in the drive system operating field (0 ≤ ωM< ωMmax, 0 ≤ M< Mmax). The presented proposals open a new perspective of unavoidable research of drive motors and systems, making it possible to compare objectively the energy efficiency of different types of motors and drive systems.

scholarly journals On Power Stream in Motor or Drive System

2016 ◽  
Vol 23 (4) ◽  
pp. 93-98 ◽  
Author(s):  
Zygmunt Paszota
Keyword(s):  
Energy Efficiency ◽  
Thermal Efficiency ◽  
Power Flow ◽  
Drive System ◽  
Energy Losses ◽  
Flow Energy ◽  
Power Increase ◽  
Drive Systems ◽  
Physical Quantities ◽  
Direction Opposite

Abstract In a motor or a drive system the quantity of power increases in the direction opposite to the direction of power flow. Energy losses and energy efficiency of a motor or drive system must be presented as functions of physical quantities independent of losses. Such quantities are speed and load. But the picture of power stream in a motor or drive system is presented in the literature in the form of traditional Sankey diagram of power decrease in the direction of power flow. The paper refers to Matthew H. Sankey’s diagram in his paper „The Thermal Efficiency of Steam Engines“ of 1898. Presented is also a diagram of power increase in the direction opposite to the direction of power flow. The diagram, replacing the Sankey’s diagram, opens a new prospect for research into power of energy losses and efficiency of motors and drive systems.

scholarly journals Determination of Coefficients of Energy Losses Occurring in a Constant Capacity Pump Working in a Typical Hydrostatic Drive

2019 ◽  
Vol 26 (1) ◽  
pp. 159-166
Author(s):  
Grzegorz Skorek
Keyword(s):  
Energy Efficiency ◽  
Drive System ◽  
Energy Losses ◽  
Motor Speed ◽  
Hydraulic Motor ◽  
Viscosity Change ◽  
Building Models ◽  
Nominal Pressure ◽  
Low Efficiency ◽  
Drive Systems

Abstract In order to assess possibilities of energy saving during hydrostatic drive system operation, should be learned, and described losses occurring in system. Awareness of proportion of energy, volume, pressure, and mechanical losses in elements is essential for improving functionality and quality of hydrostatic drive systems characterized by unquestionable advantages. In systems with too low efficiency there is increase of load, mainly in case of pump load, which can lead to higher risk of failure, necessity of repair or replacement, as well as to shorten service life of system. Coefficients ki, given in subject literature by Paszota, describe relative value of individual losses in element. They make it possible to assess proportions of losses and assess value of energy efficiency (volumetric, pressure, mechanical) resulting from losses occurring at nominal pressure pn of system in which element is used. As a result, thanks to knowledge of coefficients ki of individual losses, it is possible to determine losses and energy efficiency of components operating in hydraulic system as well as efficiency of system with defined structure of motor speed control as function of speed and load coefficient of motor. Knowledge of coefficients of energy losses occurring in system elements (pump, hydraulic motor, conduits, and motor) allows building models of losses and energy efficiency of element working in system and energy efficiency of system as whole composed of elements. Mathematical models of losses and energy efficiency in system must take into account conditions resulting from applied structure of system, from level of nominal pressure, from rotational speed of motor driving pump shaft, from viscosity change of applied hydraulic oil. Article presents method of determining coefficients of axial piston pump used in typical hydrostatic drive system with proportional control. Values that can be assumed for these loss coefficients for other hydraulic pumps are also given.

scholarly journals Application of D-Decomposition Technique to Selection of Controller Parameters for a Two-Mass Drive System

Energies ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 6614
Author(s):  
Radosław Nalepa ◽  
Karol Najdek ◽  
Karol Wróbel ◽  
Krzysztof Szabat
Keyword(s):  
Analytical Formula ◽  
Drive System ◽  
Decomposition Technique ◽  
Motor Speed ◽  
Control Structures ◽  
Drive Systems ◽  
The Impact ◽  
The Mathematical Model ◽  
Theoretical Considerations ◽  
Selection Of

In this work, issues related to the application of the D-decomposition technique to selection of the controller parameters for a drive system with flexibility are presented. In the introduction the commonly used control structures dedicated to two-mass drive systems are described. Then the mathematical model as well as control structure are introduced. The considered structure has only basic feedbacks from the motor speed and PI type controller. Due to the order of the closed-loop system, the free location of the system’s poles is not possible. Large oscillations can be expected in responses of the plant. In order to improve the characteristics of the drive, the tuning methodology based on the D-decomposition technique is proposed. The initial working point is selected using an analytical formula. Then the value of controller proportional gain is decreasing, until the required value of overshoot is obtained. In the paper different advantages of the D-decomposition technique are presented, for instance calculation of global stability area for the selected gain and phase margin, the impact of parameter changes, and additional delay evident in the system. Theoretical considerations are confirmed by simulation and experimental results.

scholarly journals Field of Work and Energy Efficiency of Hydrostatic Drives on the Example of Two Tested Systems with Proportional Control of the Cylinder’s Speed

2019 ◽  
Vol 49 (4) ◽  
pp. 203-219
Author(s):  
Grzegorz Skorek
Keyword(s):  
Energy Efficiency ◽  
Power Flow ◽  
Drive System ◽  
Energy Losses ◽  
Test Results ◽  
Hydraulic Motor ◽  
Power Increase ◽  
Physical Quantities ◽  
Direction Opposite

Abstract The presented test results are an example of simulating determination of the hydrostatic field of the drive system and the energy efficiency of the system as a dependence on the speed and load coefficients of the hydraulic motor used in the system. The issues related to the determination of energy losses and energy efficiency of the hydraulic motor or drive system, which should be determined as dependent on the physical quantities independent of these losses, were also discussed. A Paszota diagram of the power increase in the direction opposite to the direction of the power flow, replacing the Sankey diagram of the power decrease in the direction of the power flow in the hydraulic motor or in the drive system was analyzed.

scholarly journals Energy efficiency of a hydrostatic drive with proportional control compared with volumetric control

2013 ◽  
Vol 20 (3) ◽  
pp. 14-19 ◽  
Author(s):  
Grzegorz Skorek
Keyword(s):  
Energy Efficiency ◽  
Hydraulic Systems ◽  
System Quality ◽  
Motor Speed ◽  
Complete Evaluation ◽  
Proportional Control ◽  
Variable Capacity ◽  
Low Efficiency ◽  
Hydrostatic Transmissions ◽  
Drive Systems

Abstract There are uninvestigated areas connected with behaviour of elements in hydraulic systems with different structures. Unawareness of proportions of the energy, volumetric, pressure and mechanical losses in elements is often the case. Problems connected with energy efficiency are essential for improvement of functionality and quality of hydrostatic drive systems, characterised by unquestioned advantages but also by relatively low efficiency in comparison with other types of drive. Energy efficiency of hydrostatic transmissions, particularly those with throttling control of the motor speed, and also efficiency of the hydraulic servo-mechanism systems may be in fact higher than the values most often quoted in publications on the subject. Possibility of calculating the real value of the hydraulic system overall efficiency as a function of many parameters influencing it, becomes a tool of complete evaluation of the designed system quality. The paper compares efficiencies of systems with cylinder proportional control and efficiency of the system volumetric control by a variable capacity pump. Presented are also two schematic diagrams of the investigated hydrostatic systems, their principle of operation and problems of studying losses in elements and energy efficiency of systems consisting of a feed assembly, control set and cylinder.

scholarly journals Resonant Suppression Method Based on PI control for Serial Manipulator Servo Drive System

2020 ◽  
Vol 103 (3) ◽  
pp. 003685042095013
Author(s):  
Xiaopeng Li ◽  
Dongyang Shang ◽  
Haiyang Li ◽  
Fanjie Li
Keyword(s):  
Dynamic Characteristics ◽  
Pi Controller ◽  
Drive System ◽  
Pi Control ◽  
Motor Speed ◽  
Servo Drive ◽  
Serial Manipulators ◽  
Drive Systems ◽  
Servo Drive System ◽  
Serial Mechanism

A typical serial manipulator consists of a servo motor, a serial mechanism and an independent joint placed between the motor and the serial mechanism. Both the time-varying characteristics of the inertia of the serial mechanism and the flexibility characteristics of the independent joint are widely found in serial manipulator servo drive systems. These two characteristics not only increase the resonance magnitude of serial manipulators, but also affect the dynamic characteristics of the system. In order to obtain a stable output speed of serial manipulators, the variable parameters of a PI control strategy is applied to a serial manipulator servo drive system. Firstly, dynamic model of a serial manipulator servo drive system is established based on a two-inertia system. Then the transfer function from motor speed to motor electromagnetic torque is derived by the state-space equation. Furthermore, the parameters of the PI controller are designed and optimized utilizing three different pole assignment strategies with the identical radius, the identical damping coefficients, and the identical real parts. The results indicate that a serial manipulator servo drive system can obtain good dynamic characteristics by selecting parameters of the PI controller appropriately.

scholarly journals Measuring Instruments Used at the Research and Accuracy of Defining the Efficiency of Drive Systems

2019 ◽  
Vol 26 (2) ◽  
pp. 129-135
Author(s):  
Grzegorz Skorek
Keyword(s):  
Energy Efficiency ◽  
Test Stand ◽  
Energy Losses ◽  
Measuring Instruments ◽  
Motor Speed ◽  
Hydraulic Motor ◽  
Accuracy Of Measurements ◽  
Drive Systems ◽  
The Mathematical Model

Abstract The aim of the article is to look at the possibility of accurately determining the energy efficiency of drive systems thanks to the use of high quality sensors and measuring instruments. The types of measuring instruments used on the test stand are presented. The results of experimentally determined efficiencies and simulationally determined efficiencies of two hydrostatic systems with throttling control were compared, which are fed with a constant capacity pump. The choice of the analysed systems is not accidental. There is still a view in the literature about limited possibilities of energy systems with proportional control. The research stand was very carefully designed and made. The applied measuring instruments were characterized by high accuracy of measurements. The issues related to the determination of energy losses and energy efficiency of the engine or drive system, which should be determined as dependent on the physical quantities independent of these losses, were also discussed. For laboratory verification, measurement methods were developed, the test stand was adapted and automated. It consists of tested system and loaded system. The measurements during the tests were saved on the computer disk. In order to be able to compare the efficiency of the overall system with the efficiency obtained on the basis of the simulation, coefficients ki determining the energy losses of individual elements of the system were calculated. The research showed a large convergence of the mathematical description of energy losses in the elements of the system and the efficiency of the system with reality. The mathematical model enables accurate simulation determination of the energy efficiency of the system at each point of its field of operation, i.e. at each speed and load of the controlled hydraulic motor. The range of motor speed and load variation can also be accurately determined simulationally.

scholarly journals Analysis of Torque Ripples of an Induction Motor Taking into Account a Inter-Turn Short-Circuit in a Stator Winding

Energies ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3626 ◽  
Author(s):  
Wojciech Pietrowski ◽  
Konrad Górny
Keyword(s):  
Early Stage ◽  
Short Circuit ◽  
Torque Ripple ◽  
Drive System ◽  
Electrical Machines ◽  
Stator Winding ◽  
Permanent Magnet Synchronous Machines ◽  
Noninvasive Diagnostics ◽  
Drive Systems ◽  
Commercial Applications

Despite the increasing popularity of permanent magnet synchronous machines, induction motors (IM) are still the most frequently used electrical machines in commercial applications. Ensuring a failure-free operation of IM motivates research aimed at the development of effective methods of monitoring and diagnostic of electrical machines. The presented paper deals with diagnostics of an IM with failure of an inter-turn short-circuit in a stator winding. As this type of failure commonly does not lead immediately to exclusion of a drive system, an early stage diagnosis of inter-turn short-circuit enables preventive maintenance and reduce the costs of a whole drive system failure. In the proposed approach, the early diagnostics of IM with the inter-turn short-circuit is based on the analysis of an electromagnetic torque waveform. The research is based on an elaborated numerical field–circuit model of IM. In the presented model, the inter-turn short-circuit in the selected winding has been accounted for. As the short-circuit between the turns can occur in different locations in coils of winding, computations were carried out for various quantity of shorted turns in the winding. The performed analysis of impact of inter-turn short-circuit on torque waveforms allowed to find the correlation between the quantity of shorted turns and torque ripple level. This correlation can be used as input into the first layer of an artificial neural network in early and noninvasive diagnostics of drive systems.

Research on the power sharing capacity of a dual power open-end winding PMSM drive system for vehicular applications

2021 ◽  
pp. 095440702110078
Author(s):  
Yifan Jia ◽  
Zhonghua Huang ◽  
Liang Chu ◽  
Xiaoxiang Na ◽  
Nan Xu ◽  
...  
Keyword(s):  
Power Flow ◽  
Permanent Magnet Synchronous Motor ◽  
Drive System ◽  
Power Sharing ◽  
Power Sources ◽  
Voltage Vector ◽  
Vector Distribution ◽  
Maximum Torque Per Ampere ◽  
Open End Winding ◽  
Dual Power

An open-end winding permanent magnet synchronous motor (OW-PMSM) fed by dual inverter is a competitive option for the drive system of dual power electric vehicles. It allows manageable power flow between two isolated power sources through the motor without requiring a DC/DC converter. Based on the mathematical model of the OW-PMSM and the principles of power sharing, this paper first compares the power sharing capacity among some existing torque regulation algorithms, including unit power factor (UPF) control, maximum torque per ampere (MTPA) control, and constant back electromotive force (CBE) control. Then a control algorithm named minimum voltage vector amplitude (MVVA) is presented, which features covering the maximum motor operating range and the maximum power sharing range under the linear voltage vector distribution. Simulation results confirm the validity of the proposed MVVA control, and demonstrate its advantages in vehicular applications.

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