scholarly journals Power management of variable capacitors in electrical grid systems according to the criterion of mini-mum energy loss

2022 ◽  
Vol 25 (6) ◽  
pp. 741-752
Author(s):  
S. S. Girshin ◽  
E. G. Andreeva ◽  
K. V. Khatsevskiy ◽  
V. M. Trotsenko ◽  
N. A. Melnikov ◽  
...  
Keyword(s):  
Energy Loss ◽  
Reactive Power ◽  
Minimum Energy ◽  
Operating Time ◽  
Energy Losses ◽  
Integral Calculus ◽  
Grid Systems ◽  
Electrical Grid ◽  
Variable Capacitor ◽  
Inflection Points

The aim is to manage the transmitted reactive power in electrical grids using variable capacitor batteries according to the criterion of minimum energy loss under different annual reactive load schedules and different numbers of variable capacitor sections. The main theoretical relations were obtained by the methods of mathematical modelling and integral calculus using the theory of optimal control. The influence of the power and number of sections in a capacitor battery on energy losses in the grid was estimated using computational experiments. Dependencies for energy losses in a capacitor battery, as well as for reducing energy losses in the grid, were obtained. These expressions are valid for linearized load schedules. It is shown that the dependences of energy losses in a capacitor battery and the reduction of losses in the grid on the section power have inflection points and pass through a maximum. The presence of inflection points is associated with a change in the number of capacitor sections operating throughout the year. The presence of a maximum is explained by the fact that, with an increase in the power of the capacitor battery, its operating time decreases under the complete number of variable sections. It is established that the batteries of static capacitors with two variable sections can reduce energy losses when transmitting reactive power by over 90%. For three- and four-section static capacitors, the loss reduction is close to 100%. The reduction in energy losses increases when approaching maximal levels of annual reactive load. Energy losses in electrical grid systems can be reduced by capacitor batteries with no more than three or four variable sections. In most cases, this can be achieved by two-section capacitor batteries.

scholarly journals Optimized Economic Loading of Distribution Transformers Using Minimum Energy Loss Computing

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Ayman Agha ◽  
Hani Attar ◽  
Ashish Kr. Luhach
Keyword(s):  
Energy Loss ◽  
Reactive Power ◽  
Minimum Energy ◽  
Total Power ◽  
Design Stage ◽  
Energy Losses ◽  
Load Factor ◽  
Load Profile ◽  
Distribution Transformers ◽  
Two Phases

This paper presents an approach to achieve the Economic Loading of Distribution Transformer (ELDT) based on minimizing the active energy loss. The effects of the transformer on-load and no-load losses, load factor (LF), and load loss factor (LSF) on the total energy losses are considered. The adopted technique in this paper consists of two phases, where ELDT is determined analytically in the first phase, and the load profile adequated (LSF) is statistically obtained in the second one. The results declare that the proposed technique is suitable for the shifts system mode of operation such as in industrial plants. Moreover, this paper investigates the effect of the total active and reactive power and energy losses on ELDT. Finally, numerical examples with software analyses are performed as a valuable tool, which supports the decision-makers to decide trustfully the size of the transformer and its capacity (kVA) during the design stage, as well as to determine the economic loading during the operation based on the effective factors, that is, total power, energy losses, and the load profile.

Minimum Energy Control of Multibody Systems Utilizing Storage Elements

2009 ◽  
Author(s):  
Werner Schiehlen ◽  
Makoto Iwamura
Keyword(s):  
Multibody Systems ◽  
Optimal Trajectory ◽  
Design Method ◽  
Equations Of Motion ◽  
Minimum Energy ◽  
Operating Time ◽  
Minimum Energy Control ◽  
Robot Systems ◽  
Optimal Design Method ◽  
The Relationship

In this paper, we consider the problem to minimize the energy consumption for controlled multibody systems utilizing passive elastic elements for energy storage useful for robot systems in manufacturing. Firstly, based on the linearized equations of motion, we analyze the relationship between the consumed energy and the operating time, and the optimal trajectory using optimal control theory. Then, we verify the analytical solution by comparing with the numerical one computed considering the full nonlinear dynamics. After that we derive a condition for the operating time to be optimal, and propose the optimal design method for springs. Finally, we show the effectiveness of the design method by applying it to a 2DOF manipulator.

A Study on Modified Model Predictive DPC of Rectifiers

2013 ◽  
Vol 441 ◽  
pp. 328-331
Author(s):  
Hui Zhao ◽  
Biao Wang ◽  
Hong Jun Wang ◽  
You Jun Yue
Keyword(s):  
Power Control ◽  
Reactive Power ◽  
Operating Time ◽  
Sampling Period ◽  
Switching Frequency ◽  
Direct Power ◽  
Direct Power Control ◽  
Voltage Vector ◽  
Control Scheme ◽  
Result Show

In this paper, we study a modified predictive direct power control scheme (P-DPC).This scheme which based on model predictive control (MPC) uses a discrete rectifier model to infer the predictive direct power control theme again, and selects the operating time of voltage vector and voltage vector to realize fixed switching frequency through setting the minimum power errors of each sampling period. This control scheme has a lower switching frequency compared to MP-DPC; and it is still simple and clear implemented in the stationary reference frame directly, meanwhile, it does not need PI controllers or voltage-oriented controllers compared to other developed control schemes. We make simulations using MATLAB. The result show the excellence of this novel predictive direct power control scheme through improving the switching frequency, current THD and active power and reactive power quality compared to MP-DPC and LUT-DPC.

scholarly journals A Method of Predicting the Energy Losses in Vaneless Diffusers of Centrifugal Compressors

1989 ◽  
Author(s):  
Huashu Dou
Keyword(s):  
Experimental Data ◽  
Energy Loss ◽  
Total Energy ◽  
Wall Friction ◽  
Energy Losses ◽  
Flow Conditions ◽  
Centrifugal Compressors ◽  
Flow Losses ◽  
Vaneless Diffusers ◽  
Good Agreement

The flow losses in the veneless diffusers of centrifugal compressors is investigated. It is found that the total energy loss in vaneless diffusers is a function of Bsin2 α0 when inlet flow conditions and radius ratio between inlet and outlet are given. A wall friction coefficient equation is derived and a method of predicting the total energy loss excepting mixing loss is presented. A comparison is made between results obtained from this method and experimental data generated by the author as well as data from the literature. Good agreement is obtained.

Optimization-Based Design of a Leg Mechanism via Combined Kinematic and Structural Analysis

1994 ◽  
Author(s):  
W. B. Shieh ◽  
S. Azarm ◽  
L. W. Tsai ◽  
A. L. Tits
Keyword(s):  
Energy Loss ◽  
Degrees Of Freedom ◽  
Controller Design ◽  
Minimum Energy ◽  
Problem Formulation ◽  
Minimal Energy ◽  
Interactive Optimization ◽  
Joint Forces ◽  
Four Bar Linkage ◽  
Optimization Based Design

Abstract We study a recently proposed compound two degrees of freedom planar leg mechanism consisting of a four-bar linkage and a pantograph. In this mechanism, one degree of freedom is used for normal walking to provide an ovoid path which emulates that of humans while the other is used only when necessary to walk over obstacles. Potential advantages of such a compound mechanism are fast locomotion, minimal energy loss, simplicity in controller design, and slenderness of the leg. To exploit these to the fullest, a multiobjective optimization-based design problem formulation is proposed with the following four design objectives: (i) minimum leg height, (ii) minimum of the maximum joint forces, (iii) minimum leg mass, and (iv) minimum energy loss for a walking cycle. In addition, this problem formulation takes into account a combination of mechanism requirements and structural requirements. Several tradeoff solutions are obtained using the Consol-Optcad interactive optimization-based design package.

THE ENERGY LOSS, THE DETERIORATION DEPTH, AND THE LIGHT OUTPUT FOR HEAVY IONS IN ZnO:Zn

1967 ◽  
Vol 45 (12) ◽  
pp. 4039-4051 ◽  
Author(s):  
L. Hastings ◽  
A. van Wijngaarden
Keyword(s):  
Energy Loss ◽  
Heavy Ions ◽  
Light Output ◽  
Average Energy ◽  
Ion Beams ◽  
Low Energy ◽  
Energy Losses ◽  
Sufficient Energy ◽  
Low Energy Ions ◽  
Total Average

Local regions on the surface of ZnO:Zn phosphor samples were deteriorated by a large number of low-energy ions. In this manner thin films which did not luminesce under ion bombardment were prepared. The phosphor samples were then scanned across energetic ion beams with sufficient energy to traverse the thin phosphor films. By comparing the luminescent response to this ion excitation in the damaged and undamaged portions of the phosphor surface, the total average energy losses of 1H, 4He, 14N, 40Ar, and 84Kr in passing through the films were determined. It was found that the energy losses for the heavier projectiles, when compared with the energy loss of hydrogen, are appreciably smaller than the energy losses predicted by the Lindhard and Scharff theory.The deterioration depth of the phosphor under prolonged bombardment is proportional to the speed of the damaging projectiles.

Energy losses of ions implanted in matter

1996 ◽  
Vol 11 (11) ◽  
pp. 2876-2883 ◽  
Author(s):  
J. H. Liang ◽  
K. Y. Liao
Keyword(s):  
Energy Loss ◽  
Nuclear Energy ◽  
Critical Energy ◽  
Carbon Films ◽  
Electronic Energy ◽  
Energy Losses ◽  
Nuclear Energy Loss ◽  
Light Ions ◽  
First Moment ◽  
First Four Moments

A set of simple and accurate formulae for the first four moments of nuclear and electronic energy losses is proposed. A new variable is introduced to include the finite maximum-impact-parameter effect in the nuclear stopping process, which is assumed to be infinite in most studies. A critical energy at which the electronic energy loss is equal to the nuclear energy loss is also defined. It determines whether the nuclear or the electronic stopping process is the dominant mechanism in terms of incident-ion energy. The critical energy increases for heavy ions implanted in heavy target materials during the first moment of energy loss. The second moment of electronic energy loss is important only for light ions implanted at high ion energies. The third and fourth moments of nuclear energy loss are much larger than those of the electronic energy loss for all ion-target combinations. Theoretical predications of the projected ranges and range stragglings for gold ions implanted in carbon films are close to the experimental data when these proposed four moments of nuclear and electronic energy losses are considered.

Energy Efficient Cam-Follower Systems

1983 ◽  
Vol 105 (4) ◽  
pp. 681-685 ◽  
Author(s):  
F. Freudenstein ◽  
M. Mayourian ◽  
E. R. Maki
Keyword(s):  
Energy Efficiency ◽  
Energy Loss ◽  
Energy Efficient ◽  
Energy Savings ◽  
Functional Dependence ◽  
Minimum Energy ◽  
Optimization Strategy ◽  
Cam Follower ◽  
Return Spring ◽  
Rating Factor

The energy loss in cam-follower systems due to friction between moving parts can be a significant contributor to the power loss in machinery. Considering the total number of cam-operated machines in manufacturing and other operations, the energy savings obtainable by improving the efficiency of the average cam-follower system by even a small percentage would be significant. In this investigation a new rating factor—an energy-loss coefficient proportional to the energy loss at the cam-follower interface—has been defined and evaluated. The rating factor relates to energy efficiency in a manner analogous to the way in which the well-known rating factors for velocity, acceleration, and shock relate to the kinematic characteristics of the cam-follower system. Two cam-follower configurations have been considered: 1) a follower motion governed by both cam and return spring, and 2) a follower positively driven by the cam. In both cases it was found that cam curves with identical rise and rise times can differ substantially in energy efficiency thereby demonstrating the significance of an energy-optimization strategy in the design of cam-follower systems. The nature of the functional dependence of the energy loss on system parameters has been identified and a minimum energy-loss limit established.

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