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The governor system used by many pulp and paper facilities with steam power generation creates many challenges. Challenges such as inadequate response times; poor speed regulation; analog control drifting; high maintenance and support costs; expensive or unavailable parts; and extended lead times. Machine availability is affected and extended generator downtime may result. Governor replacement provides...
Multivariable predictive control, MPC, has been used in the continuous process industry for more than a decade. This strategy relies on a model created with test data from the process. The modeling produces a matrix of relationships between the "manipulated variables" and the "control variables" and "constraint variables". The MPC supervisory control software supplies...
The paper presents a case study to show how Weyerhaeuser, Dryden Operations improved its power distribution system reliability. This paper focused mainly on the changes that were made on the 115 kV and 13.2 kV power distribution systems. The protection and synchronizing schemes were discussed, and the author shows how the addition of circuit switchers provided flexibility to perform maintenance on...
This panel discusses energy incentives, strategies and programs available to the pulp and paper industry from motors to corporate management. At the process level, US Department of Energy surveys indicate that within process industries, electric usage by motors and drives accounts for as much as two-thirds of all electric usage. By adopting best practices, electric usage for motor driven equipment...
New techniques in software architecture and development have empowered users by giving them access to real-time plant data in a fluid and versatile environment. These solutions allow you to custom configure a control screen right from your Web browser with analog gauges, digital gauges, charts, spider charts and more. Data is sent in real-time from your PLCs directly to a central repository on the...
The subject of electrical hazards analysis has been recognized by a small segment of the electrical industry for many years. The petrochemical industry and many government institutions have performed research on this subject for over twenty years. For the most part however, the electrical industry, at least at the user level, has largely ignored the subject, essentially reacting to catastrophic accidents,...
The instantaneous trip can be used to reduce arc flash energy levels at 600 volt and 5 kV MCCs by minimizing the time to clear faults. The instantaneous is often not used since coordination with large motor starters can be lost. Which is more important? A digital multifunction relay may be able to use the Fourier transform algorithms for the instantaneous trip function to improve coordination with...
Energy evaluation and planning are important in industry for overall energy savings. Traditionally these functions are realized in wired systems formed by communication cables and various types of sensors. However, the installation and maintenance of these cables and sensors is usually much more expensive than the cost of the sensors themselves. Recent advances in wireless communications, micro-electro-mechanical...
Pulp contamination affects motors in the tank area of pulp & paper machines, coating the inter-fin channels, partially blocking the air intake area, and producing motor overheating even for operation below rated condition. This paper reports testing performed that evaluates the benefits of using protective covers to prevent pulp fibers from reaching the inter-fin channels and air intake area....
The scope of a typical arc flash hazard analysis often extends well beyond the conventional limits of a short circuit evaluation. When evaluating equipment such as motor control centers (MCCs) and bus ducts, each individual feeder circuit should be evaluated to determine the incident energy for the downstream protected locations. Depending on the impedance between the overcurrent protection and the...
Var/power factor control for generators has often been the preferred operating control mode for pulp and paper power plants over voltage regulation to reduce the need for constant reactive power monitoring by plant operators. Today, for those machines located in the Western United States, the North American Reliability Council (NEPC) and Western Electric Co-coordinating Council (WECC) are ruling that...
Low-voltage resistance-grounded systems may provide significant advantages to the facility in terms of system reliability and safety. However, maintenance of these systems is more complex than for solidly grounded wye systems and improper first-fault isolation and lack of timely repair may present a risk to the facility. Identifying the location of ground faults within the distribution system is the...
With the increasing of non-linear loads in electric power system, power quality distortion has become a serious issue in recent years. In paper and pulp industries, due to presence of concentrated high power non-linear loads such as electric drives, this problem is a greater concern. In this paper, the impacts of power quality distortions such as voltage sag and swell on the operation of electric...
This paper provides documentation of experiences of three PPIC members with various lineshaft driven pulp and/or paper machines. While these experiences can be explained, they may seem to defy nature. Slowdowns, erratic behavior and the like do happen. The paper provides three specific cases that are of interest and do show that while all may seem right with the world, strange things do happen
IEEE Std 519-1992 is a useful document for understanding harmonics and applying harmonic limits in power systems. Despite many years of good use there is still some confusion about how to apply certain aspects of the standard. This paper discusses some of those, as well as related issues that are helpful in working with harmonic limits. There is considerable debate as to precisely how some elements...
This paper presents estimated equipment operating costs and energy consumption to compare a steam turbine drive and a VFD electric motor drive for two different drive systems. The author presented data and conclusions from an actual project that was engineered and installed several years ago. The author also presents data and make statements on several similar applications that are now being, or were...
This paper explores the applicable standards currently in place in industry and assesses their impact on IR sightglass and port design, implementation and corresponding safety in use
Improved medium voltage control equipment designs, including enhanced structural protection systems, have continued to evolve in support of improved personnel protection. Recent changes to some standards, such as the NFPA-70E, have emphasized the need to look for improved safety compliance to mitigating the risks associated with the operation and maintenance of electrical equipment. The requirements...
Continuously corrugated armored type cables are being specified and used to supply electrical power from pulse-width modulated (PWM) style inverters to motors, pumps, fans, etc. The proper installation of these cables is important to the operation of the inverter-motor system. This paper reviewed the proper methods to be used when installing continuously corrugated armored cable including termination...
The paper is based upon modifications implemented in the protection and grounding systems of a large paper mill and describes selective ground fault protection for a 13.8 kV system, with multiple bus-connected generators, synchronous bus ties and utility interconnections. The ground fault current in the system is reduced from existing 3400 A to 500 A and a hybrid-grounding system is implemented for...
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