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The aim of this paper is to describe a model for dynamic simulation of a TMP refiner. The temperature profile along the radius of the refiner, outlet consistency and motor load are considered as outputs of the simulation, whereas the chip screw speed and dilution water flow setpoints are the inputs. The dynamic model of the refiner, as such, has been derived from first principles. The motor load and input dynamics, however, are based on black-box identifications. The model has been implemented in MATLABISIMULINK. Simulations are compared to corresponding data from experiments with the refiner.

This paper proposes a comparison between the PWM control and Digital control strategy between cascaded multilevel inverter where the conventional method produces 2n+1 output level for n independent DC sources and the digital control strategy produces 2n+1−1 output level for the same n independent DC sources also with the same number switches. This paper also brings out the advantage of using Digital control over the conventional PWM control by producing a low total harmonic distortion level (THD) level for R-load. Also the paper compares the performance of both the method in a Real time load. This simulation is done with the help of MATLAB/SIMULINK

In the chemi-thermo-mechanical pulping (CTMP) process, refiners used to convert wood chips to pulp are keyelements in determining the final physical and papermaking properties of pulp. This paper presents the design of a constrained niultivariable adaptive controller for a wood chip refiner. The control objective is to maintain two output variables, refiner motor load and blow-line consistency at their set points by adjusting three manipulated variables, transfer screw speed, refiner hydraulic pressure and dilution flow rate. The control algorithm is based on Generalized Predictive Control (GPC) with consideration for the constraints on process input variables. Computer simulations are presented to demonstrate the advantages of the proposed control algorithm.

This paper introduces a comprehensive shift schedule for a two-speed automatic transmission of pure electric vehicle. Considering about driving ability and efficiency performance of electric vehicles, the power-based shift schedule is proposed with three principles. This comprehensive shift schedule regards the vehicle current speed and motor load power as input parameters to satisfy the vehicle driving power demand with lowest energy consumption. A simulation model has been established to verify the dynamic and economic performance of comprehensive shift schedule. Compared with traditional dynamic and economic shift schedules, simulation results indicate that the power-based shift schedule is superior to traditional shift schedules.

We present the realization of quick turning motion of a humanoid robot on its toes via slipping between its feet and the floor. A rotation model is described on the basis of our hypothesis that turning via slip occurs as a result of minimizing the power caused by floor friction. Using the model, the trajectory of the center of the foot can be generated to realize the desired rotational angle. Toe joints are used to realize quicker turningmotion, while avoiding excessive motor load due to frictional torque. Quick slip-turn motion with toe support is successfully demonstrated using a humanoid robot HRP-4C.

This paper analyzes the dynamic characteristics of motor load on partial motor stalled conditions and illustrates the describing drawbacks of the traditional “3-order induction motor + ZIP (constant impedance, constant current or constant power)” load model in these situations. Based on the characteristics of motor load slip trace, the paper proposes a slip trace equivalent load model. The slip coherency approach is utilized for load modeling and the Levenberg-Marquardt-Fletcher (LMF) method is exploited for load parameter identification. The proposed model can display the dynamic performance of motor load in all kinds of disturbances including the partial motor stalled conditions. The new model also provides an observation tool for partial motor stalled situations. Simulation results are presented in this paper to validate the proposed load model as well.

Positive feedback anti-islanding controls are designed within the inverter controllers to facilitate the islanding detection for the inverter-based distributed generation (DG). These anti-islanding controls, however, can have influence on the dynamics of DG systems. This paper investigates the impact of the positive feedback anti-islanding controls on the small-signal stability of the grid-connected inverter-based DG system with motor load. The small-signal model of the investigated DG system is developed and the sensitivity analysis is conducted based on the small-signal model. The analysis results show that the strong positive feedback gain of the anti-islanding controls will reduce the capacity of the DG motor load. (5 pages)

This paper proposes the use of independent component analysis and fuzzy neural network for online fault detection of induction motors. The most dominating components of the stator currents measured from laboratory motors are directly identified by an improved method of independent component analysis, which are then used to obtain signatures of the stator current with different faults. The signatures are used to train a fuzzy neural network for detecting induction-motor problems such as broken rotor bars and bearing fault. Using signals collected from laboratory motors, the robustness of the proposed method for online fault detection is demonstrated for various motor load conditions. (6 pages)

In the previous paper, it was described that the same motion as the cam displacement curves can be obtained by applying the feedforward control method; in other words, the inverse to a DC motor driving system. In this paper, it is clarified that the velocity feedback for the motor driving system reduces the effect of the real motor parameter deviation from the setting values of the inverse, even if including the displacement feedback. Furthermore, the residual vibration characteristics of one degree of freedom vibration load connected to the motor axis compensated by the above-mentioned means are studied. The numerical and experimental results in the case of the basic motion curves as the parabolic and harmonic motion cam curves are similar to the mechanical cam behavior. In addition the availability of the inverse system method for the motor output is assured dynamically, and the possibility of the open control positioning by the motor is obtained.

In order to obtain some insight into the performance of an air-magnetic circuit breaker in a steam environment, a 134.8 kV circuit breaker was required to interrupt a 9.3 MVA motor load while subjected to 110 degrees C steam. The authors describe the technical concerns leading to the testing, how the testing was performed, and the observations recorded. Two tests were performed, at 88 s after steam release and some 7 min later, when steam condensation and breaker temperature were at their maximum (for the given steam profile). The breaker successfully interrupted the load twice and there was no flashover. The closing controls failed on the second reclosure attempt. >

The method of mathematical modeling of power supply systems with motor load in the transient modes is proposed in the article. This method provides the possibility of submitting the electric network of any configuration. The model is based on equations in the phase coordinates and allows simulating as electromagnetic and electromechanical components of transient modes. For the formation of equations of transient processes it is used nodal method, for the numerical integration of the equations of transient processes it is applied implicit methods, the formation of the system model is implemented on the basis of discrete models of electric machines. The mathematical model provides a complete picture of the electrical network, allows simulating all kinds of managing and disturbing external influences to meet the challenges of emergency management, reducing the number of accepted assumptions. In addition, a possibility of multi-variant calculations for research and study of factors affecting the quantitative characteristics of the transient processes is opened in the case of the presence of computer model.

A missing phase circuit breaker containing the type of electronic module for protecting motor load during electric power source failure or current overloads has been designed for this paper. This breaker is small, easy to install into main circuit breaker and more inexpensive than existing breakers.

The islanding phenomena of PV inverter are obviously influenced by the regenerative loads such as motor load and resonance circuit. In Japanese situation, the motor loads of 1 KW or less are used in the certification test and evaluated in order to test the islanding detection device in a severer case from the viewpoint of safety. However, the motor load is not very clear in the specification of a standard motor to use for the examination so that there are diverse and unspecified kinds. Accordingly, it is certainly not easy to standardize the motor load for certification test around the world. On the other hand, in IEEE929-2000 and IEC62109CD2 standard, resonance circuit is used instead of motor load for the examination with consideration of regenerative load characteristic. Therefore, it is necessary to confirm whether the resonance circuit can simulate the motor load properly under the islanding condition

The method of fault positions has been used to study the post-fault voltage sags in the supply to a large chemical industry plant. The main concern is faults in the on-site distribution systems. The during-fault and post-fault voltages have been simulated by using the PSCAD/EMTDC package. A comparison with a measured sag has been made, showing good agreement. The simulation results taught us that post-fault voltage sags mainly occur during faults in the MV networks. Strengthening the supply, or reducing the (post-fault) motor load are needed to solve this.

This article proposes a method for the modeling and control of a two stage thermo-mechanical pulping process (TMP). Experimental data was collected from operational refiners without affecting the pulp production and with no modifications to the facility. The experimental data is used to identify the model parameters. The model predicts refiner motor load and the pulp properties of Canadian standard freeness (CSF), shive content and long fibre content as a function of the production rate, the infeed dilution water flow rate and the refiner plate gaps. The model of the plant is used as a guide, whereby the plant operators can predict the future output pulp properties.

A pattern recognition technique based on Bayes minimum error classifier is developed to detect broken rotor bar faults and static eccentricity in induction motors at the steady state. The proposed algorithm uses stator currents as input without any other sensors. First, rotor speed is estimated from stator currents, then appropriate features are extracted. The produced feature vector is normalized and fed to the trained Bayes minimum error classifier to determine if motor is healthy or has incipient faults (broken bar fault, static eccentricity or both). Only number of poles and rotor slots are needed as pre-knowledge information. Theoretical approach together with experimental results derived from a 3 hp AC induction motor show the strength of this method. In order to cover many different motor load conditions data are derived from 10% to 130% of the rated load for both a healthy induction motor and an induction motor with a rotor having 4 broken bars and/or static eccentricity.

Three eider ducks were handled every 4 min for 16 min to measure their cloacal temperature. This simple handling triggered a rise in their core temperatures from 41.5+/-0.6 degrees C at minute 0 to 43.5+/-0.5 degrees C at minute 16. This increase in body temperature occurred with no obvious motor load from the eiders, but was facilitated by peripheral vasoconstriction and, moreover, was blocked significantly by salicylate, suggesting that the increase in temperature was due to fever. After 10 days of similar handling, the mean fever-like responses displayed by the ducks was significantly lower than their responses of day one, showing a habituation to the emotional stimulation. The eider's heart rate was measured continuously before, during and for a 10-min session following a 1-min handling period. Results showed that the eiders displayed a tachycardia during handling and for 2-3 min posthandling. Such tachycardia is another sign of emotion in animals [Am J Psychol 39 (1927) 106]. Our study showed therefore that eider ducks are prone to emotions and, when emotionally stressed, will display a fever-like response and a tachycardia. Our results on ducks are similar to responses obtained from studies on more terrestrial birds in similar conditions (e.g., chicken [Physiol Behav 69 (2000) 541]), but are in opposition to the bradycardia and the observed decreases in temperature [Hvalradets Skr 22 (1940) 1; Acta Physiol Scand 46 (1959) 231] of birds forcibly submerged.

The growth of cattle majorly affected by the type of fodder and its digestion system. To gain the healthy growth, cattle fed green grass and additional concentrate in form of mixed agricultural wastes such as rice straw, corn straw, etc and tofu residues in cattle fodder. Since cattle have no upper incisor, (insisivus), it use combination of its molar and its tongue to cut the grass or rice straw or corn straw, as the result more fodder like fresh grass, rice straws or corn scraws are wasted. If the wasted re-use by giving it back to cattle, it will not eat it, so it will cause inefficiency in feeding livestock. In order to solve that problem a chopping and mixing tool is needed, by using fuzzy method to control a dc motor constant speed to chopping grass, rice straws and corn straws, and then mixing with additional concentrate such as tofu wasted. Rice straws, corn straws and fresh grass are chopped in chopping section and mixed with tofu residues in the mixing section. When all the food material mixed and stired, the weight will be measures using a current sensor ACS712-20A. This sensor is used to measure the motor load. Furtheremore, if the more food materials place into this device, so, the faster the dc motor will rotate. When this device loaded 3000gr, the current measure is 4.53 ampere. The load position is not smooth will result the reading of the sensor always fluctuated. As the result, the fuzzy method applied will be optimal when the current is 4.22 ampere and the PWM fuzzy is higher than 252-mark is legible

The pulp beating process has been developed over a long period of time and new evaluation methods are required to improve the understanding of the fibre beating mechanisms. This work is representing an initial attempt to provide a model for evaluation of the low-consistency pulp beating process. The simplified modelling produced a diagram for the relationship between motor load and pulp production, which reminds of a corresponding diagram used in wood grinding. The load-production relationship is expressed by P/n versus m2/c, where P = net motor load, n = rotational speed, m = dry pulp production and c = pulp consistency. Beating at constant specific energy resulted in load-production combinations forming a specific linear correlation irrespective of specific edge load SEL, but provided that the rotational speed was constant. On the other hand, when the rotational speed increased under conditions of constant SEL of 2.5 J/m, the load level remained unchanged, as the pulp production increased.

A simple refiner control strategy aimed at minimizing variations in freeness of a Ultra High Yield Sulphite (UHYS) pulp has been implemented in a newsprint mill. The feeder screw speed is being manipulated to compensate for variations in the bulk density of the chip feed and to maintain a constant motor load at the primary refiners. This ensures a more constant mass flow rate through the primary refiners which translates into a more constant primary specific energy. This has resulted in a reduction in motor load fluctuations of about 60% and a reduction in freeness variations of 40%. The final pulp freeness is regulated by manipulating the plate gap of the secondary refiners using on-line freeness measurements made at the outlet of the latency chest. Control of the secondary plate gap has led to an additional 35% reduction of the variation in freeness. This two-stage refining control strategy has reduced the 2-sigma confidence interval for variation in pulp freeness from 48ml to less than 14ml, a reduction of more than 70%. The complete strategy has reduced the refiner energy consumption by 5% and has had a beneficial impact on production. In addition, the strategy has compensated for changes in cooking conditions and their effect on the refining properties of the chips.

This paper summarises the outcome of a great deal of work done collaboratively within the UK Electricity Industry to develop improved methods for the calculation of short circuit currents in transmission and distribution networks. This was done against a background of a number of limitations associated with IEC 909, the only internationally published standard method. ER G74 sets out a procedure which requires a more detailed assessment of short circuit currents with a fuller representation of system pre-fault conditions and taking account of dynamic load fault circuit contribution. It is hoped that as experience is gained, particularly with the measurement of LV motor load fault contribution, improvements can be made to the procedure. It is also hoped that the work done so far will go a long way towards influencing a revision of IEC 909 to make it more appropriate to interconnected transmission and distribution networks and to computer simulation techniques.

The principles of steady operation of single-screw extruders have been developed in Chapters 6 and 8 and their implications for operation discussed in Chapters 9 and 11. The principles and operation of twin-screw extruders have been covered in Chapter 10, where it is shown that the wide variety of designs entails operation largely guided by manufacturer’s instructions. This is even more the case of dismantling and cleaning of twin-screw machines, which will therefore not be discussed in this chapter. However, an attempt is made to cover more practical aspects of operation to complement the theory of singles-crew machines, including methods of achieving and maintaining safe and steady operation, starting-up and changing running conditions, shut-down and cleaning, and scrap recovery.

At present, due to the complexity of the wood chip refining processes, there are no suitable physical or parametric models available which can be used when studying different control strategies. It is shown that the process, which consists of two serially linked refiners, can be modelled as two multiple input, single output systems. To each refiner the dynamics from the chip flow to the motor load and from dilution water to the motor load are examined. It is shown that the pressure cannot be ignored in the model and that the motor load of the first refiner can be used as an input when modelling the second refiner. This indicates the possibility to use the load for feed forward control. The time stability of the models found was examined. The survey showed a small change in the model characteristics, but the ability to simulate the motor toads was not significantly reduced.

A formula for calculating the power requirements of an armored face conveyor (e.g. for coal mining applications) is presented. Techniques to determine the conveyor speed-torque curve and to estimate the acceleration time for a loaded conveyor are also given. Using this information, an algorithm to estimate the maximum length for a face conveyor is developed. An application of the algorithm to power system analysis is presented. By using the developed algorithm, the performance as well as the maximum length of a longwall face conveyor can be readily evaluated. >

Three possible control approaches for a two quadrant chopper, capable of providing positive current and voltage in either direction from a fixed d.c. input, are compared in this paper. The comparative study has been carried out for two types of loads -(a) Highly inductive load (ripple free current) and (b) Motor load The performance at the input as well as the load terminals is analysed and the results are presented in terms of normalised values. The boundaries between continuous and discontinuous conduction are also drawn to facilitate an estimation of filter inductance.

A method of sizing motors is proposed which is intended to provide the least energy consumption and more starting torque. The technique compares steady-load motor efficiency with the efficiency when operated on various cyclic load configurations. The performance of unconventional and conventional pumping units is compared for calculated and measured torques. Field data are used to verify the model. For cyclic loads, motors are more efficient when operated near half-load. The reason for improved efficiency when using unconventional units is shown. It is shown that the best efficiency will be achieved with a motor operating at 40-50% of its rating. A ten-point improvement in efficiency is obtained when the motor load changes by a factor of 2 and the final load is near 50%. A motor provides adequate starting torque for a conventional unit only when the motor rating is two times the average load. >

The application of microprocessors for the control of a voltage-source cycloconverter is described. One of the processors is specifically designed to handle the real-time estimation of the true current zero of a dynamic motor load, thereby determining the optimum instant for current transfer between the equivalent positive and negative converter groups. An algorithm to obtain a fast initial estimate in each half cycle of the output and another algorithm to perform recursive estimation of the cross-over location have been developed.

A motor load analyzer instrumented to a high intensity mixer was examined for its ability to monitor the granulation process with varying formulation and processing parameters. A lactose/microcrystalline cellulose blend with povidone as the binder was used as the test system.The motor load analyzer was able to note chopper operation and liquid addition methods. However, it could not differentiate between povidone addition as an aqueous solution or as part of the lactose microcrystalline cellulose blend, followed by massing with water. The compression characteristics of the granulations depended upon chopper usage, and povidone and liquid amounts, and their methods of addition.

The authors treat the control of a chip refiner to produce wood pulp, where the incremental gain between the motor load and the plate gap is subject to sudden changes due to pad collapse. Passive adaptive control with fault detection, active suboptimal dual control, and dual-control solutions are discussed. For dual control, the choice of the control criterion is crucial, as it must reflect the peculiarities of the process. Two nonquadratic performance indices are proposed, and the myopic solutions are computed. Simulations show the superior performance offered by these indices. >

This paper describes an application of carrier-current relaying combined with rapid reclosure of circuit breakers by means of which the continuity of service to a large industrial load supplied by a long single-circuit line was improved. A 110-kv line 120 miles long, forming part of an interconnected loop, has been equipped in this way to clear faults and restore service in approximately one second. The effect of the connected motor load on circuit interruption is also discussed.

The rating given to a motor is the manufacturer's guarantee of the motor performance under the conditions given on the name plate. Assuming that this rating is entirely safe, then the successful functioning of the motor depends entirely upon the application engineer's analysis of the particular duty that the motor will be required to perform. Where the required motor output is practically constant the application is simple; however, in many cases the motor load is apt to be anything but constant, consisting of loads of all degrees of magnitude, and in such cases the economically correct application is especially difficult. The past improvements made in the motor design, mechanically and electrically, have resulted in greater importance of the motor-operating temperatures, in fact in the great majority of cases the motor rating is limited only by the motor temperature. It is obvious then that correct motor applications depend to a very great extent upon correct operating temperatures. Ratings such as the continuous, short-time, normal, and dutycycle ratings give the performance of the motors under some particular conditions; however, the duty required of a great number of industrial and railway motors will not agree with any of the above ratings. Thus the application of motors to cranes, hoists, steel mills, and railways must be made with the knowledge of the motor's performance under one or more arbitrary conditions. In general the two ratings which should be known for motor application to such irregular duty are the continuous and a short-time rating.

Previous research has reported mixed findings regarding executive function (EF) abilities in developmental coordination disorder (DCD), which is diagnosed on the basis of significant impairments in motor skills. The current study aimed to assess whether these differences in study outcomes could result from the relative motor loads of the tasks used to assess EF in DCD. Children with DCD had significant difficulties on measures of inhibition and planning compared to a control group, although there were no significant correlations between motor skills and EF task performance in either group. The complexity of the response, as well as the component skills required in EF tasks, should be considered in future research to ensure easier comparison across studies and a better understanding of EF in DCD over development.

During the summer months of 1954, the spare 190-C process pump unit was required to be placed in service for extended periods of time due to the motor winding temperatures exceeding the manufacturers recommended maximum operating limits. With nine unit operation each pump was required to supply approximately 9800 gpm to maintain the established power level of the 105-C Reactor. An operating condition requiring all process pump units to be in service simultaneously is-not desirable. Such a condition not only subjects the Reactor Unit to a possible unscheduled outage should trouble develop in any component of a pump assembly but in all probability would delay a startup of the Reactor Unit until arrangements could be completed to operate at reduced pressure in order to eliminate sustained over-heating of the pump drive motors. The purpose of this report is to summarize the activities undertaken during this investigation in order to arrive at satisfactory conclusions and recommendations for eliminate the over-heating of the related motor windings under present and proposed operating conditions.

Grooved feed extruders have been around since about the 1960s. These extruders offer considerable advantages over conventional extruders, such as higher throughput, better stability, and the ability to process very high molecular weight polymers. There are some important disadvantages as well, for instance, higher motor load, wear is more likely, high pressures in the grooved region, and the screw design has to be adapted. The disadvantages of the grooved feed extruder disappear when the grooved feed extruder is made with a mechanism that allows adjustment of the groove depth. This paper will report on the development of grooved feed extruders that incorporate an adjustment mechanism that allows the depth of the grooves to be changed, during actual operation, from zero to full depth. Operational data from actual extrusion experiments are presented.

A comparative study of the state of the cardiovascular systems of adolescents not engaged in sports and young athletes of the same age has been performed. According to the indices recorded in the resting state, a relative lag of the functional development of the systems of autonomic control of the cardiovascular system was shown for adolescent nonathletes at an age of 13–14 years as compared with young athletes. This lag is compensated by the age of 15–16 years, but the adequate level of autonomic activity is reached through the activation of central regulatory mechanisms (sympathetic and humoral), with a relatively low contribution of the peripheral vagal and baroreflex mechanisms. This conclusion is confirmed by the results of assessment of the reactivity of the cardiovascular system of adolescents with different levels of motor activity in a functional test with limited pulmonary ventilation.

THE H420A switch is a newly developed high-performance hermetically sealed 120-volt d-c aircraft limit switch. This switch was specifically designed to carry 3 1/2 kw and to interrupta 1.8-kw motor load, 15 times a second, for duty cycles of 15 seconds each.