• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
• /
• 2007.05a
• /
• pp.83-125
• /
• 2007

Increasing energy costs have caused profitability problems for paper suppliers. Therefore unprofitable lines are being closed down. The actions aiming for improved profits are focused either on cost savings or on increasing the capacity of the remaining machines. The runnability of a paper machine and its total efficiency have a significant effect on energy consumption. Producing one ton of waste paper consumes at least as much energy as producing the same amount of sellable end product. New automation solutions enable significant cost-effective improvements to the total efficiency of a line without large investment projects. The measures focus on minimizing changes, interruptions, interruption recovery times and grade change times. Newest actuators, online quality measurements and wet end analysators create an improvement potential, which can be optimally implemented with the latest machine direction control solutions, based on model predictive control concepts. Equally, drying management is significant to the energy consumption. The newest control strategies optimize the use of various drying actuators for different situations; either by responding to changes as efficiently as possible or by using only the cheapest energy sources in stable situations. An even steam supply, which is vital for paper machines, is achieved with control for the power plant steam network. This makes possible to avoid the delays upon starting the paper machine and assure an even steam supply for the drying section and the actuators. This document describes means which have brought significant energy and raw material savings for paper machines. Metso Automation has provided efficiency improvement packages, which are usually based on optimized control of dry weight and drying in all running conditions. The solutions are based on performance analysis, on which the estimations for improvement potential and the necessary actions are based on. Typically benefits on an annual level have been from hundreds of thousands of euros to over one million euro. For example, variations in dry weight have been decreased more than 50%. The results are presented with a few examples. Additionally, the analysis models, adjustment solutions and the changes in running methods with which the results were achieved, are presented.

• Journal of Electrical Engineering and Technology
• /
• v.9 no.3
• /
• pp.812-819
• /
• 2014

The proposed technical work attempts to compare the two key technologies of power distribution, i.e. direct current (DC) and alternating current (AC) in a fiscal manner. The DC versus AC debate has been around since the earliest days of electric power. Here, at least four types of a low voltage DC (LVDC) distribution are examined as an alternative to the existing medium voltage AC (MVAC) distribution with an economic assessment technique for a project investment. Besides, the sensitivity analysis will be incorporated in the overall economic analysis model to cover uncertainties of the input data. A detailed feasibility study indicates that many of the common benefits claimed for an LVDC distribution will continue to grow more profoundly as it is foreseen to arise with the increased integration of renewable energy sources and the proliferation of energy storage associated with the enhanced utilization of uninterruptible power supply (UPS) systems.

• Proceedings of the KIEE Conference
• /
• 2007.07a
• /
• pp.842-843
• /
• 2007

In this paper, the proper rebate level can be decided in programs of energy savings by solving an optimization problem with an objective function, which satisfies a maximum value of total energy savings. And then, each prevalence amount is estimated by using virtual Bass model which is a function of rebate level, instead of the conventional Bass model. Finally, by cost/benefit analysis of the estimated prevalence amounts, the priority order is obtained for the investment of each program. The priority order obtained in this way may result the improvement of investment efficiency for DSM(Demand-Side Management) programs and the reasonable plan decision for supply and demand in power system.

• Journal of the Korean Solar Energy Society
• /
• v.32 no.2
• /
• pp.11-18
• /
• 2012

Diesel fuel is expensive because transportation to remote areas adds extra cost, and it causes air pollution by engine exhaust. Providing a feasible economical and environmental solution to diesel generators is important. A hybrid system of renewable plants and diesel generators can benefit islands or other isolated communities and increase fuel savings. Renewable energy is, however, a natural source that produces a fluctuating power output. In this paper, hybrid power system of the marado lighthouse is proposed to supply stable power in the stand-alone hybrid power system. The proposed hybrid power system consists of the diesel generator, wind turbine, photovoltaic, fuel cell, and battery bank. To decrease the carbon emissions and find the optimization, the cost analysis of hybrid system is simulated using HOMER program and the optimized hybrid power system is designed.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.64 no.3
• /
• pp.384-392
• /
• 2015

This paper presents an economic assessment of large-scale Li-ion battery energy storage systems applied to Korean power system. There are many applications of the battery energy storage systems (BESSs) and they can provide various benefits to power systems. We consider BESSs to the energy time-shift application to Korean power system and evaluate the benefits from the application of BESS in the social perspective. The mixed integer programming (MIP) algorithm is used to resolve the optimal operation schedule of the BESS. The social benefits can include the savings of the fuel cost from generating units, deferral effects of the generation capacity, delay of transmission and distribution infra construction, and incremental CO2 emission cost impacts, etc. The economic evaluation of the BESS is separately applied into Korean power systems of the Main-land and Jeju island to reflect the differences of the load and generation patterns.

• KIEE International Transactions on Power Engineering
• /
• v.11A no.4
• /
• pp.45-50
• /
• 2001

The impact evaluation of a DSM program is a very important issue since the results are used to determine the sustainability of a program. In general. to estimate the impacts of a DSM program it is required to measure the electricity usage changes before and after a program. Since the measurement-based approaches cost highly, most of the conventional evaluations are based on the average figures. However estimation of the average-based impacts can lead to both distorted results of over/under estimation of kW and kWh savings and non-optimal DSM planning. In this paper, we have developed a new multi-point measurement approach which can evaluate kW and kWh savings of a DSM program more exactly. To do this, the saving rate and operating rate are defined and set as the function of load factor of a customer, and these rates are incorporated with the conventional diffusion function of Bass to project the future impacts of a DSM program. The case study is performed on the inverter program of Korea by using the suggested approach.

• Journal of Electrical Engineering and Technology
• /
• v.2 no.1
• /
• pp.42-49
• /
• 2007

For electricity markets to function in a truly competitive and efficient manner, it is not enough to focus solely on improving the efficiencies of power supply. To recognize price-responsive load as a reliability resource, the customer must be provided with price signals and an instrument to respond to these signals, preferably automatically. This paper attempts to develop the Windows-based load management system in competitive electricity markets, allowing the user to monitor the current energy consumption or billing information, to analyze the historical data, and to implement the consumption strategy for cost savings with nine possible scenarios adopted. Finally, this modeling framework will serve as a template containing the basic concepts that any load management system should address.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.1 no.1
• /
• pp.19-31
• /
• 2007

RFID tag is detected by an RFID antenna and information is read from the tag detected, by an RFID reader. RFID tag detection by an RFID reader is very important at the deployment stage. Tag detection is influenced by factors such as tag direction on a target object, speed of a conveyer moving the object, and the contents of an object. The water content of the object absorbs radio waves at high frequencies, typically approximately 900 MHz, resulting in unstable tag signal power. Currently, finding the best conditions for factors influencing the tag detection requires very time consuming work at deployment. Thus, a quick and simple RFID tag detection scheme is needed to improve the current time consuming trial-and-error experimental method. This paper proposes a back-propagation learning-based RFID tag detection prediction scheme, which is intelligent and has the advantages of ease of use and time/cost savings. The results of simulation with the proposed scheme demonstrate a high prediction accuracy for tag detection on a water content, which is comparable with the current method in terms of time/cost savings.

• Proceedings of the KIEE Conference
• /
• 1996.07b
• /
• pp.692-694
• /
• 1996

Recently, rapid increase in electricity demand, tremendous financial need for new power plant construction, and environmental problem have led to search for more efficient energy production and energy conservation technologies. Due to the potential energy and cost savings to electric utilities, DSM plays an important role in the electric resource planning. However, implementation of cost-effective DSM program requires appropriate analysis methodologies and procedures. In this study, we present the cost-effectiveness analysis model for DSM program evaluation. We also present a case study to analyze DSM program.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.18 no.2
• /
• pp.117-122
• /
• 2013

The distributed power conversion LED driver circuit using parasitic inductance is proposed in this paper. while the conventional LED driver circuit is composed of the large size devices and heatsinks, the proposed circuit can be realized with the small sized no heatsink based. since the processing power can be effectively distributed. Also by using the wire parasitic inductance of the LED string, the proposed circuit can be implemented without external magnetic device. As a result, the proposed circuit which features the small size and volume con be realized even without LED driver module(LDM) board. since, all the device can be attached to the existing LED array Module(LAM) board. Therefore, it features that cost savings and volume reduction of circuit. To confirm the validity of the proposed circuit, theoretical analysis and experimental results from a distributed power conversion LED driver circuit prototype are presented.