Search

The International Technology Roadmap for Wide-Bandgap Power Semiconductors (ITRW) has four distinct technical working groups, each providing its own perspective on the technology and industrial drivers for the adoption of wide-bandgap (WBG) power semiconductors in power electronics. This article summarizes the progress toward an initial roadmap for the packaging and integration working group of the ITRW.

Silver nanowires (AgNWs) have inspired many research interests due to their better properties in optical, electric, and flexible applications. One such exploitable use is as the electrical conductive fillers for print electronics. In this paper, AgNWs with mean a diameter of 80 nm and mean length of 13.49 &mu, m were synthesized using the polyol solvothermal method. A sonication-induced scission process was used to obtain AgNWs with a length range of 7.64&ndash, 11.21 &mu, m. Further AgNWs inks were prepared with the as-synthesized AgNWs as conductive fillers in anhydrous ethanol. The conductive inks were coated on resin coated photographic paper substrate using the knife coating process and dried at room temperature. The effects of the number of layers of AgNWs coating, the concentration of AgNWs, and the length of AgNWs on the microstructure and electrical properties of samples were investigated by scanning electron microscopy and using the four-point probe method. The results show that the conductivity of the AgNWs coating increases with the increase in the number of layers in the AgNWs coating, concentration and length of the AgNWs.

To paraphrase the son of lady macduff in william Shakespeare's Macbeth, "DC is not dead, for all your saying!" When the paper industry was first electrified, the only type of machine capable of variable-speed operation was powered by dc. There were numerous manufacturers and users who knew how the machines worked and how to maintain them. Over time, the control of these machines has changed from relatively simple analog to complex digital systems. Those whose task it was to keep the machines healthy have since moved on to other things. The modern pulp, paper, and forest industries still have applications powered by dc equipment; however, the most recent installation trend is toward ac machines.

Разработан способ производства упаковочной бумаги повышенной непрозрачности, белизны и прочности. Он заключается в изготовлении бумаги из волокон сульфатной беленой целлюлозы из хвойной и лиственной древесины с добавлением тонкоизмельченных волокон целлюлозы, диоксида титана и поливинилового спирта. Это позволяет повысить разрывную длину бумаги, белизну, непрозрачность, цветовосприятие и устойчивость печати, снизить линейную деформацию бумаги, The study presents results of the design of a paper wrapping material, which simultaneously possesses high functional (strength and opacity), aesthetic (whiteness), and technological properties (color acceptance and print sharpness). The latter is a particularly important element in the marketing strategy of food manufacturers because it enables creation of the packaging that is attractive to consumer and thus may increase sales.According to results of the conducted study, it was found that the set of proposed activities could increase discontinuous paper length to over than 5000 m and opacity to 92 %, while the linear deformation is reduced by 2–2.5 times in comparison with the analogue. The introduction of titanium dioxide as a filler to the paper pulp provides a whiteness level of 88 %. The use of polyvinyl alcohol fiber enhances color acceptance and print stability. This is due to the creation of resistance to the plucking of fibers and particles of the filler by paint during printing and friction. The results are confirmed by the uniform mass indicators per 1 m2 and humidity in 8 points.It is advisable to use results of the study performed in the production of wrapping paper, as well as when selecting packing material for one or another food product, which is especially important at present – in the context of European integration and production of goods that meet international standards, Розроблено спосіб виробництва пакувального паперу підвищеної непрозорості, білості та міцності. Він полягає у виготовленні паперу з волокон сульфатної біленої целюлози з хвойної і листяної деревини з додаванням тонкоподрібнених волокон целюлози, діоксиду титану і полівінілового спирту. Це дозволяє підвищити розривну довжину паперу, білість, непрозорість, фарбосприйняття та стійкість друку, знизити лінійну деформацію пеперу

Like some of us, the paper industry has been around a long time. Unfortunately, so has a lot of the installed equipment. There have been some upgrades and improvements to machine design over the years, particularly in the areas of insulation and condition monitoring. However, the installed base has not necessarily kept the pace, due in part to the reliability built into older machinery. Today's facilities are under deeper scrutiny as system efficiency, machine reliability, and equipment condition-monitoring improvements are becoming the norm as the industry tries to position itself for the next century.

This paper studies automated tuning of cross-directional model predictive control for industrial paper-making processes under user-specified model parameter uncertainties. Automated parameter tuning algorithms are developed to reduce the variability of the actuator and measurement profiles in the spatial domain and to achieve satisfactory performance in terms of worst case settling times and worst case control signal overshoots in the temporal domain for given parametric uncertainties. Due to decoupling properties of the spatial and temporal frequency components, the controller design and parameter tuning can be realized separately. For the spatial design and parameter tuning in the presence of parametric uncertainties, the undesirable high-frequency components in the actuator profile are suppressed via an appropriate design of the weighting matrix $S_{b}$ using the real-valued Fourier matrix approach. For the temporal design, a temporal filter is adopted to smooth the reference trajectory, where the parameter in the temporal filter is carefully tuned to achieve a tradeoff between the worst case settling time and the worst case control signal overshoot. Finally, the effectiveness of the proposed tuning algorithms is verified using a system model extracted from the pulp and paper industry.

Many papers have been written about the phenomenon of arc flash, the causes of arc flash, how to mitigate specific arc flash problems, and how to design arc flash issues out from the beginning. This paper will discuss the overall process of completing an engineering incident energy analysis and remediation project in a pulp and paper mill. Most mills are not fortunate enough to receive sufficient funding to do the whole study and a remediation process all at once. This paper explores how a Midwestern pulp and paper mill worked over several years to get through the process of the study, remediation efforts, and the establishment of an overall electrical safety program.

A simple method for microfluidic paper-based sample concentration using ion concentration polarization (ICP) with smartphone detection is developed. The concise and low-cost microfluidic paper-based ICP analytical device, which consists of a black backing layer, a nitrocellulose membrane, and two absorbent pads, is fabricated with the simple lamination method which is widely used for lateral flow strips. Sample concentration on the nitrocellulose membrane is monitored in real time by a smartphone whose camera is used to collect the fluorescence images from the ICP device. A custom image processing algorithm running on the smartphone is used to track the concentrated sample and obtain its fluorescence signal intensity for quantitative analysis. Two different methods for Nafion coating are evaluated and their performances are compared. The characteristics of the ICP analytical device especially with intentionally adjusted physical properties are fully evaluated to optimize its performance as well as to extend its potential applications. Experimental results show that significant concentration enhancement with fluorescence dye sample is obtained with the developed ICP device when a fast depletion of fluorescent dye is observed. The platform based on the simply laminated ICP device with smartphone detection is desired for point-of-care testing in settings with poor resources.

Paper machine dryer sect ions create challenges in tuning due to gear backlash. This problem is amplified when older paper machines are upgraded with newer, higher-performance drive systems. The newer drive systems can achieve a much higher degree of control, which can fatigue the mechanical drivetrain. Most often, backlash is experienced during the speed regulator tune-up [1]. The speed regulator response is modified in an effort to improve stability while in backlash. However, there are other tune-up considerations that must be considered. A dryer section can be pulled from a downstream section, which can cause its applied torque to be near zero, resulting in speed instability. This article investigates the cause of this instability and presents a novel solution for preventing it.

The Micro-Nano Science and Technology Division of the JSME (Japan Society of Mechanical Engineers) promotes academic activities to pioneer novel research topics on microscopic mechanics [...]

The minimum variance controller has been extensively used as a benchmark in the performance assessment of both univariate and multivariate control loops when time delay is the fundamental performance limitation. In this paper, the spatial and temporal performance limitations in the cross-directional (CD) control of paper machines are analyzed. The idea of minimum variance benchmarking is extended to the CD process based on these performance limitations. Based on an industrial CD controller, a user-specified benchmark, which is more practical and less aggressive, is also proposed. In addition, several related performance indices are proposed for the CD process based on both the minimum variance benchmark and the user-specified benchmark. Illustrative examples from a paper machine simulator and industrial data sets are provided to show the effectiveness of the proposed performance indices.

Radio frequency identification (RFID) systems for the paper industry is an emerging research topic due to the need for an automated identification system for the paper industry which would carry on the identification codes of paper and board reels throughout their life cycle. This paper discusses the application of passive ultra-high frequency (UHF) RFID systems to the paper industry. Challenges, benefits, and the application environment of using passive UHF RFID systems in the paper industry are presented and discussed. The major challenges are development of globally operable tag antenna designs and integration of reader units and reader antennas to paper handling machinery. To confront and solve these challenges, this paper presents novel tag antenna designs for paper and board reel identification and proposes solutions for reader and reader antenna integration to paper handling machinery. In addition, the identification locations within the paper reel supply chain and the effects of RFID systems to supply chain visibility are presented and discussed. In addition, test results of using passive UHF RFID systems in the paper industry environment are presented.

This paper solves the controller tuning problem of machine-directional predictive control for multiple-input–multiple-output (MIMO) paper-making processes represented as superposition of first-order-plus-dead-time (FOPDT) components with uncertain model parameters. A user-friendly multi-variable tuning problem is formulated based on user-specified time domain specifications and then simplified based on the structure of the closed-loop system. Based on the simplified tuning problem and a proposed performance evaluation technique, a fast multi-variable tuning technique is developed by ignoring the constraints of the MPC. In addition, a technique to predict the computation time of the tuning algorithm is proposed. The efficiency of the proposed method is verified through Honeywell real time simulator platform with a MIMO paper-making process obtained from real data from an industrial site.

The pulp and paper industry offers a wide spectrum of research challenges to the control systems community. Implementations of control technology, production planning, scheduling, and operations can lead to tangible improvements in terms of increased capital returns and reduced environmental impact. This paper presents an overview of operations in an integrated pulp and paper mill and reviews the control challenges for important process units. It also summarizes current and future research areas in the pulp and paper industry

This paper presents a new strategy for steam pressure control during web breaks in the paper machine. The aim was to restart paper production with the same drying properties of the cylinder as before the break. A detailed physical dynamic model of the drying cylinder has been developed. The accuracy of the model has been verified through experiments made at the M-real paper mill in Husum, Sweden. Verifications are made both during normal operation and during web breaks. The dynamic model has been reduced in order to derive simple transfer functions which were used to find the optimal steam pressure trajectory during web breaks. The resulting strategy has been tested on a paper machine with good results and it has been well received at the mill.

Electrical equipment supplying and distributing energy is used in every pulp and paper industrial process. Many components made of various metallic and dielectric materials are vulnerable to corrosive atmospheres often present in the pulp and paper industrial facilities. Corrosion of electrical conductors may result in fast and irreversible deterioration, causing production loss and safety hazards. The paper reviews the most severe corrosion problems effecting conductivity of electrical contacts that result in overheating of electrical equipment used in this industry. A number of various protecting means are suggested to slow down corrosion of silver and copper and other metals most often used in electrical equipment. The paper discusses implementations and the value of various condition-monitoring techniques to provide timely maintenance of electrical equipment exposed to corrosive environments in the pulp and paper facilities.

Critical sections of a paper machine such as the wet end presses, size press, on-machine coater, and reel may be required to undergo large and fast load changes in normal operation. These changes must result in minimum disturbance to the ingoing sheet tension or nip roll speed in order to avoid sheet breaks or wrinkling. This paper evaluates two disturbance-rejection control techniques, one using disturbance feedforward (or disturbance input decoupling) based on a nip-pressure disturbance observer and the other using a two-degrees-of-freedom controller. Evaluations were done in both a press section and a size press section of a lightweight paper machine, and the results showed that both methods are very effective in reducing the maximum speed deviation to about 10% of the values without compensation and can operate combined with torsional oscillation compensation without interference between them

In pulp and paper plants, power transformers play a critical role in process continuity. These transformers are subject to internal short circuits, external short circuits, and abnormal operating conditions. The following protection challenges to power transformers will be explored, and methods to improve the protection are provided. First, remanence in a current transformer (CT) may cause misoperation of phase differential protection due to compromised CT performance. Heavy through-faults, sympathetic inrush, and recovery inrush all cause high current. This, combined with high remanent flux, can create a security issue. IEEE CT performance calculations will be used to support the use of dual slope differential characteristics to promote secure differential protection operation when challenged with unequal CT performance. Second, on transformer energizing, the second harmonic current has been traditionally used as a means to prevent phase differential misoperation. Certain transformers may not exhibit high enough the second harmonic, causing a dependability issue if the restraint is set too low. The use of the second and fourth harmonics for inrush detection will be shown to enhance the reliability during energizing inrush situations. Third, overexcitation can occur from abnormal operation of the utility system or the plant's excitation control. Causes of overexcitation will be outlined and the use of volts per hertz protection is explored. With overexcitation occurring from system voltage rise, the phase differential protection has been traditionally blocked using the fifth harmonic restraint. This may cause an undesired nonoperation of the phase differential protection if an internal fault occurs while the transformer is overexcited, causing a delay in tripping and severe damage to the transformer. A technique using adaptive phase differential pickup value will be illustrated to overcome this challenge. Finally, on resistance-grounded power transformers, phase differential protection sensitivity for ground faults near the neutral is decreased. The use of ground differential protection will be explored and the increased sensitivity gained will be demonstrated.

Ground faults in generator stator and field/rotor circuits are serious events that can lead to damage, costly repair, extended outage and loss of revenue. This paper explores advances in field/rotor circuit ground fault and stator ground fault protection. [1] These advanced protection strategies employ AC injection, ground differential protection and the use of hybrid grounding to reduce both internal generator ground fault levels and facility ground levels in utility-paralleled operating modes.

A rule-based expert system for the integrated control and supervision of the dry-end sections of a paper machine is proposed. This system is capable of recognizing all the normal and abnormal changes in process operating conditions, including acceleration of sections, threading of paper sheet, nip pressure activation, activation and deactivation of tension control loops, change of parent roll, and sheet break. A core part of the system is the supervision of the sensorless tension control of the dry-end sections, assuring its long-term stability.

This paper reviews the motor temperature operating consideration for totally enclosed fan cooled (TEFC), open dripproof (ODP) and weather protected II (WP-II) type of motor through 500 HP, both low voltage (LV) and medium voltage (MV). The IEEE Standard 841 has been revised as IEEE-Std 841-2001 and is expected to be in use for at least five years. The TEFC motors covered in this standard have found wide acceptance in the pulp and paper industry. Much of the material also applies to large motors sizes. The thermal impact on the stator winding, rotor core, bearings and lubrications as specified in standards and applied in mills are considered.

In the present work, the problem of controlling recipe transitions in a paper-making process is addressed, in order to avoid paper breakage and reduce paper waste. A decoupling control scheme is proposed, based on the control of speed differences between contiguous motors. This guarantees smooth and fast transitions of all the motor speeds along the production line. A front-tracking scheme is also employed, in order to adapt the recipe change to the actual plant conditions. A simulation model has been constructed and validated for a real industrial paper-making plant, and the effectiveness of the proposed control algorithm has been tested by means of simulation.

Generators are very efficient and are typically quite reliable. This article describes, key preventive maintenance actions, along with recommended cycle times of the generator. Initially, the basic preventive maintenance tasks such as visual inspection of generator components, particularly the stator windings, rotors and wedge system is discussed. An extensive generator health assessment should be done to determine what problems are most severe and need priority attention.

On Saturday night, 22 October 2016, I witnessed the Chicago Cubs clinch a place in baseball's 2016 World Series after capturing the pennant during the National League Central Division playoffs with the Los Angeles Dodgers. Not since 1945 had this baseball club been able to accomplish this extraordinary feat. It was on 28 May 1957, at a National League baseball owners midseason meeting in Chicago, that the decision was made to move the Brooklyn Dodgers franchise to Los Angeles. Chicago, of course, has always been known as a baseball town, and the young Cubs players, in their early 20s, magically captured the hearts of their devoted fans in winning their place in history once again.

A piece of paper has many useful characteristics; it is affordable, lightweight, thin, strong, and highly absorbent. These features allow inexpensive and flexible devices to be fabricated easily and rapidly. We have proposed a new field, “paper mechatronics,” which merges printed robotics and paper electronics, and to realize electronic and mechanical systems by printing. Herein, we develop a method to print an actuator and a structure on a sheet of paper. A trilayer electrothermal actuator is printed to activate a printed robot. The paper self-folds along the printed pattern to form the three-dimensional (3-D) structure of the robot body. We also investigate important factors necessary to develop a printed robot. Experiments, including finite element analysis (FEA), confirm our bimetal modeling assumption for the printed actuator and improve the locomotive ability. The key factors in self-folding are paper thickness and humidity. Our findings can improve the reliability of printed robot designs. A self-folding A7-sized paper robot demonstrates locomotion at 10 mm per step.

Emergency situations associated with falls are a serious concern for an aging society. Yet following the recent development within ICT, a significant number of solutions have been proposed to track body movement and detect falls using various sensor technologies, thereby facilitating fall detection and in some cases prevention. A number of recent reviews on fall detection methods using ICT technologies have emerged in the literature and an increasingly popular approach considers combining information from several sensor sources to assess falls. The aim of this paper is to review in detail the subfield of fall detection techniques that explicitly considers the use of multisensor fusion based methods to assess and determine falls. The paper highlights key differences between the single sensor-based approach and a multifusion one. The paper also describes and categorizes the various systems used, provides information on the challenges of a multifusion approach, and finally discusses trends for future work.

The Micro–Nano Science and Technology Division of JSME (Japan Society of Mechanical Engineers) promotes academic activities to pioneer novel research topics on microscopic mechanics. [...]

Electronic line-shafting control has demonstrated very promising features when applied to paper machine drives. To apply this new control methodology, it is necessary to develop a starting procedure for each individual section and a method for setting the parameters of the virtual line-shaft drive and in-shafts. This paper proposes and evaluates startup and commissioning procedures for electronically line-shafted paper machine drives. The procedure for acceleration of the individual sections is implemented using virtual variable-ratio gearboxes that emulate the physical clutches and conical pulleys used in the era of line-shafts. System stiffness is implemented using virtual in-shafts with active damping. Evaluation shows that the proposed virtual clutch/conical pulley assembly and active damping allow smooth acceleration of each section and maintain well-behaved response during load disturbances for all operating conditions, even with different numbers of sections effectively connected.

The model of a paper machine is very complex and difficult to describe completely by a mathematical model. There are a lot of parameters in both the wet and dry end of the machine and there is a very large time delay in the system which effects the quality of the paper being produced. Although the PID controller is widely used for these types of applications, it is often not tuned very well. In this work, a newly developed algorithm (Munro, The systematic design of PID controllers, IEE Colloquium in Robust Control: Theory, Software and Applications, Austin Court, Birmingham, 1999) is used for tuning the PID controller. Along with this controller, a Smith-predictive controller is applied to the plant and the transient and steady-state behaviours of these controllers are compared. Hardware and software implementations of the closed-loop control are also presented in the paper.

In order to enhance consumer properties of the tissue paper, effective chemicals, namely the epichlorohydrin-modified polyamide resin of different manufacturers, are selected for paper strength improvement in dry and wet conditions. The environmentally friendly Kymene 25X-Cel resin made in the USA is characterized by the highest efficiency. Also, the given resin appeared the most economic in production. Expenditure amounted to 2 kg per ton of paper. Fiber composition for paper production based on bleached sulphate softwood pulp – 40 %, bisulphate softwood pulp – 20 %, bleached sulphate hardwood pulp – 40 %, ground to 27–32°SR is developed. Such ratio of fiber semi-products provides the highest consumer properties of paper. It is found that the Kymene 25X-Cel resin should be added to the paper pulp after grinding of cellulose fibers and diluted with water prior to introduction. Under these conditions, the highest efficiency of the resin is achieved. Paper samples with different contents of the epichlorohydrin-modified polyamide Kymene 25X-Cel resin (0.2–0.8 % of absolutely dry fiber), which were compared with the paper sample made without the resin are made. It is determined that 0.6–0.8 % of absolutely dry fiber is an effective resin content in the paper composition. It allows achieving the necessary paper strength of 9.3–9.6 % for the developed fiber composition, which provides basic operational properties of finished products.

There are a number of functional protection areas on paper mill generators 20 years or older that have significant shortcomings when compared to current IEEE recommended generator-protection practices. This article identifies these protection areas and the risks of not addressing the shortcomings. It also points out the advantages of using multifunction digital relaying to upgrade generator protection as a technology that offers many advantages over older electromechanical relays. The completed upgrade project at MeadWestvaco's Luke Mill in Maryland provided a number of examples of these benefits in uncovering mill problems that, if they had gone undetected, could have resulted in costly mill shutdowns or damage to mill generators.

Previously, plant-wide disturbance analysis has looked into the propagation of faults through an industrial production process by investigating process measurements. However, the extent of the analysis has mostly been limited to a section of a plant. In this work, we propose a top-down approach which investigates measurements of the complete plant and identifies a section where the disturbance originates. Root cause analysis is carried out thereafter to pinpoint the faulty asset. The proposed approach has three novel elements: Using key performance indicators (KPI) as reference and starting point of the analysis, restricting measurements to a measurement type (e.g. flow) thus focusing on a section and applying the novel method of contribution plots of spectral PCA T 2 statistic to find the contribution of each measurement towards the disturbance observed in the KPI. The approach is described and carried out on a paper machine where a quality KPI showed an established oscillation.

Model-based controllers based on incorrect estimates of the true plant behaviour can be expected to perform poorly. This work studies the effect of model plant mismatch on the closed loop behaviour and system performance for a certain class of MIMO systems. Performance is measured using a minimum variance index and a closely related user-specified criterion. We study the effect of model plant mismatch on the output variance and performance indices. Under mild assumptions, the performance of each output in a MIMO system can be analysed independently. Moreover, we propose an approach to distinguish the effect of model–plant mismatch from the effect of changes in disturbance characteristics on closed-loop performance. We define a sensitivity measure that relates system performance to model–plant mismatch, and use it to explore this sensitivity for three realistic types of parametric modelling errors. Next, we suggest a quantitative method that compares a system's actual output to its desired response in a transient setting. The performance of the transient response is demonstrably more sensitive to the model–plant mismatch than the steady state performance. The results are illustrated on industrial paper machine data.

This paper presents two approaches for monitoring the performance of the paper making process. The first uses a neural network vibration-based condition monitoring system for providing advance warning of press felt problems. The characteristics of this system include spectral analysis through acceleration enveloping, a peak detection algorithm as a feature extractor and a neural network classifier. The second approach makes use of multivariate statistical techniques. This involves the generation of a multivariate statistical representation of nominal process behaviour. Process malfunctions are then identified by deviations from the developed model. Both approaches are successfully applied to an industrial paper machine.

This paper presents an application of Generalised Predictive Control (GPC) to the paper machine benchmark. The plant features a relatively large dead-time and severe retention level variation at the wire section. From simulations, results show that the controller has good performance when the the retention levels are at their nominal values, and that there is large output variation if the retention varies as specified.

This paper is concerned with the task of sensing in web-forming process control loops. Conventional and newly proposed measurement techniques are discussed and a new type of measurement is suggested. The new measurement method adresses the problem of paper machine "wet-end" sensing and is based on a CCD camera system which can detect the dry-line. Both the theoretical and practical aspects of the invention are investigated and the sensing system is developed into a portable measurement system which is applied to a paper machine. The paper machine measurements are analyzed and presented using nonparametric techniques based on analysis of variance. Compared to traditional scanning gauge systems the dry-line detector allows for a large reduction in the transport delay, higher data density and sampling rate, and better machine directional (MD), and cross-directional (CD) signal decomposition.

Electronic Engineering and Design Innovations are both academic and practical engineering fields that involve systematic technological materialization through scientific principles and engineering designs [...]

Historically, Class A Ground-fault circuit interrupters (GFCIs) have been responsible for a substantial reduction in residential electrocutions. Yet they have not had much success in industrial applications because of the limitation on system voltage (maximum 240 V) and the 6-mA maximum allowed leakage current. As a result, industrial personnel protection has been lagging behind its residential counterpart. UL realized this gap and defined new GFCI classes to specifically address personnel protection in industrial applications. UL 943C defines the requirements of special-purpose GFCIs that can be used on systems up to 600 V and allows for a leakage current of 20 mA. This article describes the UL 943C requirements and the newly defined GFCI classes. The difference between equipment ground-fault protective devices (EGFPDs) and GFCIs is also addressed. Finally, the application of a Class C GFCI in a pulp and paper plant is described.

Good cross-directional control of sheet variables in a paper machine depends on a number of factors. One such factor is the correct alignment of actuators with their corresponding responses. The alignment changes with time either locally or across the whole paper sheet due to a variety of reasons. In this paper, we provide an online mapping technique based on estimating the cross-correlation between actuator movement and the measurements. This procedure involves two steps–in the first step (called alignment monitoring) we determine if the current mapping is wrong at any CD position, and in the second step (called re-mapping), the alignment of actuators is corrected. The main advantage of this method is in its ability to re-align under closed loop conditions with minimal operational disruption.

In this paper, a robust controller for the paper machine benchmark problem is designed using H ∞ loop-shaping techniques. The weighting functions are tuned to minimize the effect of a sinusoidal disturbance in the filler retention level.

This paper summarises the simulation results for the different controllers applied to the benchmark paper machine simulation model. Five different cases are simulated, each for both nominal filler retention level and sinusoidally varying retention level. The results are presented in plots and tables, and also compared to what can be considered a traditionally tuned Dahlin controller with decoupling.

The IEEE Industry Applications Society (IAS) reviews paper on following topics: industrial power systems; commercial power systems; power system engineering; power system protection; electric machines; rural electric power; industrial drives; industrial power converter; power electronics devices; power electronics components; sustainable energy conversion systems; transportation systems; industrial lighting; industrial display; electrical safety; pulp industry and paper industry.

This paper considers a power system where about half the demand comprises industrial loads and some include large rotating machines. Therefore, the behaviour of these loads during system disturbances has to be considered for system stability studies. This paper describes a practical approach to the development of a Laplace transfer function (TF) model of a (paper) mill load connected to this power system. A PSCAD/EMTDCTM simulation model of the mill (the detailed model) was built from available information on the types of load within the mill. This detailed model was verified in a piece-wise manner, e.g. against individual motor starts. Instead of using the available generic load models, system identification theory is applied to evaluate the transfer function load model from simulated small signal disturbance responses. The model is developed for both voltage and frequency changes, and considers the actual frequency range of inter-area oscillations within the power system. In this paper the focus of the work is to accurately represent the mill load behaviour for small signal disturbances. It is recognised that the large signal requirements of a load model for transient stability studies are also important but the inevitable non-linearity of such a model would tend to saturate the loads’ behaviour during lesser disturbances. The performance of the developed small signal load model is tested using some practical disturbance profiles from this power system. This modelling approach allows development work to commence before real-life disturbance measurements are available since such data is currently scant. However, modern high bandwidth monitoring has recently come on-line for the mill and the TF load model will be fully verified over time as disturbance data builds up.

Torsional oscillations bound the speed loop bandwidth (BW) of industrial drives and servo systems, deteriorating the transient response to commands and to disturbances. This is especially harmful in multi-drive systems, like paper machines, that need to run synchronized. This paper presents two methods to dynamically compensate the torsional oscillations produced by the compliant components between the motor and the load: either a notch filter or acceleration feedback based on the rigid-body Luenberger observer. The evaluation includes the effect of the reducer backlash, whereby both time and frequency domain responses are used to compare the benefits of each technique in a typical paper machine section. Results show that both methods, if properly tuned, are effective techniques to reduce torsional oscillations, and are robust to parameter variations

Proper operation of the dry end of a paper machine requires some type of sheet tension control. Present systems use either indirect-speed-control-based schemes, or sensor-based direct tension control utilizing load cells or swing rolls. The indirect schemes are inadequate for most newer machines, and both types of the commonly used sensor-based schemes are invasive, expensive, require either special, or extra rolls, and add complexity to the sheet runs. This paper proposes and evaluates sheet tension estimation using only conventional motor and control signals, present in all newer drive controllers, integrated into a process model observer. This observer-based approach eliminates the need for the invasive tension transducers, and may also be used to replace the inaccurate indirect speed control schemes.

An improved estimation algorithm for use in processing data generated online by a scanning sensor is described. The algorithm is to be used as part of a paper machine control system to maintain the moisture content of the sheet at a target value. The algorithm makes use of a previously published model to rapidly estimate, in the presence of noise, cross-direction and machine-direction (CD and MD) moisture profiles. The basic algorithm consists of a modified least-squares (LS) parameter identifier for estimating CD profile deviations and a Kalman filter for estimating MD disturbances. Simulation results showing the effectiveness of the algorithm in estimating known profiles are given. Results of the offline application of the algorithm to industrial data are also given. Online tests have been performed to demonstrate the improvements in accuracy and speed of detection of process upsets. The algorithm can be extended to other measurement models. >

Thanks to their capabilities of converting various energy into motions, micro/nanomachines are believed to bring about revolutionary changes in many fields[...].

In this paper two predictive methods have been developed in order to cope with the monitoring of the corrosion phenomena in a Pulp & Paper plant. The data of the process has been collected in Wisaforest pulp mill, located in Pietarsari (Finland), in three periods characterised by three different operating conditions. Two different strategies have been adopted, firstly using a classical multi-layer perceptron and then using the neuro-fuzzy expert systems. Moreover, both nonlinear moving average models and NARMAX ones have been designed. The results obtained allow to predict the corrosion potential accurately.

A method for the control of basis weight by supervisory optimization is worked out. The objective is to determine the optimum supervisory machine speed and basis weight set point adjustments to maximize the profitability of production subject to the constraints of plant operation. The cost function consists of production cost and the loss due to rejects. An optimization scheme is worked out to calculate an optimization policy. Furthermore, the machine speed versus profit relations are developed to arrive at a supervisory machine speed that provides the globally minimized cost (maximized profit). The sampled measurements are processed to determine the variance and expected values of process variables. The expected values are used by the optimization system to determine the set point adjustments (corrections) by using the production and reject cost data. The supervisory machine speed is determined based on the optimum cost values of operation at various speeds to reach a globally minimum cost value. The implementation by distributed control systems is described, including the benefits of such a system.