Maximum Power Estimation Research Articles

The Investigation of a 6.5-kV, 1-kA SiC Diode Module for Medium Voltage Converters

This paper introduces a 6.5-kV 1-kA SiC PiN diode module for megawatt-range medium voltage converters. The analysis comprises a short description of the die and module technology and a device characterization. The effects of di/dt and temperature variation, as well as parasitic oscillations are discussed. A comparison of the results with a commercial Si diode (6.5 kV and 1.2 kA) is included. In the last section, an estimation of maximum converter output power, maximum switching frequency, losses and efficiency in a 3L-NPC converter operating with SiC and Si diodes is presented. The analyzed diode module exhibits a very good performance regarding switching loss reduction, which allows an increase of at least 16% in the output power of a 6-MVA converter. Alternatively, the switching frequency can be increased by 46%.

Non-uniform integrated Cu(In,Ga)Se2 solar cell efficiency SPICE simulation

Maximum power estimation of a single CIGS solar cell is very difficult in a large-scale non-uniform CIGS module. A distributed network SPICE model for CIGS modules is presented that predicts the impact of non-uniformity on the module performance. Maximum power is affected less by a local bad area but is seriously affected by an entire bad single cell. Results indicate that very locally formed good or bad area did not affect maximum power for a large-scale CIGS module. The proposed network SPICE model is able to not only predict module performance but also to help the improvement of the CIGS device parameter during the thin-film CIGS process.

Implementation of neural network-based maximum power tracking control for wind turbine generators

In this study, the maximum power point tracking (MPPT) of a permanent magnet synchronous generator used in a wind generator system is realized by a prototype installed in a laboratory environment. The installed prototype is modeled in a MATLAB/Simulink environment. The MPPT is realized by an artificial neural network (ANN). The obtained simulation and experimental results are compared. The maximum power estimation at various windmill speeds (rpm) of the trained ANN in determined reference speeds is analyzed. The zero crossing points of the phases are determined by a digital signal peripheral interface controller and the system is operated according to the triggering angles obtained from the ANN-based control algorithm at the maximum power points.

Estimation of maximum power generated from CIGS photovoltaic modules under non-uniform conditions

Estimation of maximum power generated from CIGS photovoltaic modules under non-uniform conditions

Muscle architecture and out-force potential of the thoracic limb in the eastern mole (Scalopus aquaticus)

Moles have modified thoracic limbs with hypertrophied pectoral girdle muscles that allow them to apply remarkably high lateral out-forces during the power stroke when burrowing. To further understand the high force capabilities of mole forelimbs, architectural properties of the thoracic limb muscles were quantified in the Eastern mole (Scalopus aquaticus). Architectural properties measured included muscle mass, moment arm, belly length, fascicle length, and pennation angle, and these were used to provide estimates of maximum isometric force, joint torque, and power. Measurements of muscle moment arms and limb lever lengths were additionally used to analyze the out-force contributions of the major pectoral girdle muscles. Most muscles have relatively long fascicles and little-to-no pennation. The humeral abductor/rotators as a functional group are massive and are capable of relatively high force, power, and joint torque. Of this group, the bipennate m. teres major is the most massive and has the capacity to produce the highest force and joint torque to abduct and axially rotate the humerus. In general, the distal limb muscles are relatively small, but have the capacity for high force and mechanical work by fascicle shortening. The muscle architectural properties of the elbow extensors (e.g., m. triceps brachii) and carpal flexors (e.g., m. palmaris longus) are consistent with the function of these muscles to augment lateral out-force application. The humeral abductor/rotators m. latissimus dorsi, m. teres major, m. pectoralis, and m. subscapularis are calculated to contribute 13.9 N to out-force during the power stroke, and this force is applied in a 'frontal' plane causing abduction of the humerus about the sternoclavicular joint. Moles have several specializations of their digging apparatus that greatly enhance the application of out-force, and these morphological features suggest convergence on limb form and burrowing function between New and Old World moles.

Power Analysis of Light Electric Vehicles Using Fundamental Calculations

This paper presents a study of the power needed by batteries to drive an electric vehicle for specific purpose using basic theory and fundamental formulas. In order to develop an electric vehicle, the energy and power requirements of the vehicle in various driving environments need to be estimated. The energy efficiency of a vehicle depends primarily upon the specific vehicle design and the environment in which the vehicle is operated. Basic parameters are set off in the beginning such as car weight and much more comprehensive parameter will developed later such as vehicle cruising velocity. Generally, four forces affect vehicle motion; aerodynamic resistance, rolling resistance, climbing resistance and acceleration power. The total of these four forces will result in an estimation of maximum power needed for the electric vehicle.

Optimum Control Strategies in Energy Conversion of PMSG Wind Turbine System Without Mechanical Sensors

The amount of energy obtained from a wind energy conversion system (WECS) depends not only on the characteristics of the wind regime at the site, but it also depends on the control strategy used for the WECS. In order to determine the gain in energy derived from one concept as compared against another, models of several autonomous WECS have been developed using Matlab Simulink software. These allow easy performance evaluations and comparisons on different control strategies used, and determine the amount of energy injected to the grid in the case of the grid-connected systems. This paper also proposes a prototype version of the control strategy of a 20-kW permanent-magnet synchronous generator (PMSG) for maximum power tracking and compares with the results produced by previous strategies. Advantages of this mechanical sensorless control strategy for maximum power estimation are demonstrated by digital simulation of the system.

Faster power estimation of CMOS designs using vector compaction-a fractal approach

Low power digital complementary metal oxide semiconductor (CMOS) circuit design requires accurate power estimation. In this paper, we present a compaction algorithm for generating compact vector sets to estimate power efficiently. Power can be estimated using dynamic (simulation) or static (statistical/probabilistic) techniques. Dynamic power estimation techniques simulate the design using a large input vector set for accurate estimation. However, the simulation time is prohibitively long for bigger designs with larger vector sets. The statistical methods, on the other hand, use analytical tools that make them faster but less accurate. To achieve the accuracy of dynamic power estimation and the speed of statistical methods, one approach is to generate a compact, representative vector set that has the same switching transition behavior as the original larger vector set. The compaction algorithm presented in this paper uses fractal concepts to generate such a compact vector set. The fractal technique quantifies correlation by a fractal parameter which can be determined faster than calculating correlation explicitly. Experimental results on circuits from the ISCAS85 and ISCAS89 benchmark suites, with correlated input vector sets, resulted in a maximum compaction ratio of 65.57X (average 38.14X) and maximum power estimation error of 2.4% (average 2.06%). Since the size of the compact vector set used for simulation is smaller, the simulation time will be shorter and will significantly speed up the design cycle.

A Monte Carlo approach for maximum power estimation based on extreme value theory

A Monte Carlo approach for maximum power estimation in CMOS very large scale integration (VLSI) circuits is proposed. The approach is based on the largely unexploited area of statistics known as extreme value theory. Within this framework, it attempts to appropriately model the extreme behavior of the probability distribution of the peak instantaneous power drawn from the power supply bus, in order to yield a close estimate of its maximum possible value. The approach features a relatively small number of necessary input patterns that does not depend on the circuit size, user-specified accuracy, and confidence levels for the final estimate, simplicity in the algorithmic implementation, noniterative single-loop execution, highly accurate simulation-based operation, and easy integration within the design flow of CMOS VLSI circuits. Experimental results establish the above claims and demonstrate the overall efficiency of the proposed approach to address the problem of maximum power estimation.

A New Statistical Method for Maximum Power Estimation in CMOS VLSI Circuits

A method for maximum power estimation in CMOS VLSI circuits is proposed. The method is based on extreme value theory and allows for the calculation of the upper end point of the probability distribution which is followed by the instantaneous power drawn from the supply bus. The main features of the method are the relatively small and circuitin-dependent subset of input patterns required for accurate prediction of maximum power and its simulative nature which ensures that no over-simplifying assumptions are made. Application of the proposed method to eight distributions, which come close to the behavior of power consumption in VLSI circuits, proved its superior capabilities with respect to existing methods.

Mapping quantitative trait loci using multiple families of line crosses.

To avoid a loss in statistical power as a result of homozygous individuals being selected as parents of a mapping population, one can use multiple families of line crosses for quantitative trait genetic linkage analysis. Two strategies of combining data are investigated: the fixed-model and the random-model strategies. The fixed-model approach estimates and tests the average effect of gene substitution for each parent, while the random-model approach treats each effect of gene substitution as a random variable and directly estimates and tests the variance of gene substitution. Extensive Monte Carlo simulations verify that the two strategies perform equally well, although the random model is preferable in combining data from a large number of families. Simulations also show that there may be an optimal sampling strategy (number of families vs. number of individuals per family) in which QTL mapping reaches its maximum power and minimum estimation error. Deviation from the optimal strategy reduces the efficiency of the method.

The Oxygen-Transporting System in Relation to Age

1. An extensive study of the functional and dimensional components of the oxygen-transporting system in relation to age and the indirect estimation of maximum aerobic power (V̇o2max.) has been conducted on eighty healthy male subjects aged 20–50 years. Measurements were made of ventilation, cardiac frequency and blood lactic acid expressed in terms of oxygen intake of 1·51/min (V̇e, 1·5; fh, 1·5 and LA, 1·5 respectively) maximum blood lactic acid, ventilation and oxygen intake, thigh (TM) and calf (CM) and total body muscle estimated from soft tissue radiographs, whole body potassium (40K), blood volume (BV), heart volume (HV), and tests of lung function. 2. In the younger subjects it was shown that the functional and dimensional capacities of the O2-transporting system were closely integrated and the performance of organs in relation to size was essentially similar. In older subjects there was a gradual decline in the overall capacity to transport oxygen which was closely associated with a decrease in the functional rather than the dimensional aspects of the cardiovascular system. In terms of a given body weight the dimensional capacities of the older subjects, BV, THb (total body haemoglobin), 40K, TM CM, were shown to be independent of age. 3. The best single guide to V̇o2max. was given by BV in subjects under 35 years of age and by HV in older subjects. By using a multiple regression on either V̇e, 1·5, fh, 1·5 and leg muscle or FVC, HV, TM and age, V̇o2max. could be estimated with coefficient of variation of ∼9%. This is ∼2% improvement on conventional methods of determining V̇o2max. from measurements of fh and V̇o2 taken at four levels of work and in addition when using the latter equation there is no need for the subject to exercise. The use of these equations and their clinical application to the testing of V̇o2max. in large community studies of physical working capacity are discussed.

ELECTRON ENERGY DISTRIBUTION FUNCTIONS AND VIBRATIONAL EXCITATION RATES IN CO2 LASER MIXTURES

The electron energy distribution function has been calculated for the plasma of a CO2–N2–He mixture using available electron—molecule cross-section data. Rates at which electrons transfer energy to the inelastic levels of CO2 and N2 were then determined. With this information, the relationship of the various electron—molecule energy exchange processes to laser performance was studied. For conditions typical of CO2 lasers, approximately 17% of the power transferred to the CO2 and N2 was found to be available for conversion to optical power. Estimates of maximum available optical power were made and found to be consistent with experimental values.