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The energy conservation achieved by utilizing waste heat in the energy and industrial sectors has became more and more important after the energy crisis in the 1970s because it plays a vital role in the potential energy-efficiency improvement. In this regard, cogeneration (combined heat and power, CHP) systems are thus becoming attractive due to the energy, economic, and environmental policies for pursuing stable electricity supply, sustainable development and environmental pollution mitigation in Taiwan. The objective of this paper is to present an updated analysis of CHP systems in Taiwan during the period from 1990 to 2010. The description in the paper is thus based on an analysis of electricity supply/consumption and its sources from CHP systems during the past two decades, and centered on two important regulations in compliance with CHP systems (i.e., Energy Management Law and Environmental Impact Assessment Act). Based on the total net power generation from CHP systems (i.e., 35,626 GWh) in 2011, it was found that the carbon dioxide reduction benefits were estimated to be around 20,000 Gg. [ABSTRACT FROM AUTHOR]

With increasing demand for power and with shortages envisioned especially during the peak load times during the summer, there is a need to boost gas turbine power. In Taiwan, most gas turbines operate in combined cycle mode for base load. Only a small portion of gas turbines operates in simple cycle mode for peak load. To prevent the electric shortage due to derating of power plants during hot days, the power augmentation strategies for combined cycles need to be studied in advance. As a solution, our objective is to add an overspray inlet fogging system into an existing gas turbine-based combined cycle power plant (CCPP) to study the effects. Simulation runs were made for adding an overspray inlet fogging system to the CCPP under various ambient conditions. The overspray percentage effects on the CCPP thermodynamic performance are also included in this paper. Results demonstrated that the CCPP net power augmentation depends on the percentage of overspray under site average ambient conditions. This paper also included CCPP performance parametric studies to propose overspray inlet fogging guidelines for combined cycle power augmentation. [ABSTRACT FROM AUTHOR]

The geochemical characteristics and Pb isotope variations in Fe-Mn deposits collected from the South China Sea (SCS) were studied in this paper. The mineralogical and chemical composition data indicate that the deposits are almost all hydrogenetic in origin. Compared with the Fe-Mn deposits in other oceans, the SCS Fe-Mn deposits have a significantly higher Pb content because of higher material supply in addition to a lower growth rate of the deposits. Pb isotope ratios in the surface of the SCS Fe-Mn deposits are relatively uniform, with a characteristic of relatively lower 206Pb/204Pb ratio. The Pb isotopic compositions of the SCS Fe-Mn deposits are controlled by the Pacific Deep Water and local inputs, which include eolian dust from the Asian continent and weathering products from Taiwan, Luzon and SCS submarine volcanic rocks. The continuously increasing 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb ratios along the transect of nodule D581 over the past 3.5 Ma are affected by the stepwise closure of the Luzon Strait that reduced volcanic material supply and the deep current strengthen at the same time. [ABSTRACT FROM AUTHOR]

Among the ancillary services, a great number of cost allocation strategies have been broadly developed in the deregulated environment. Generally, the utilization of such services can be determined by directly evaluating the actual amount of the usage or by indirectly analyzing the fair/reasonable contribution/attribution to the market participants. In the case of the primary frequency regulation (PFR) service, which is operated by the participating generating units to maintain the real-time balance between the generation and load, the discussion of the PFR service attributed to the load side has still received relatively little attention. In this paper, a new strategy of the cost allocation of the PFR service from the customer side is proposed. Two main factors, the load fluctuation and the frequent demand change, are considered to figure out the PFR reaction relating to the different substations. The design of a scheme for determining the cost allocation index of the PFR service can be applied to the presently exiting power market. In addition, the actually load series recorded from the extra-high voltage (EHV) substations of the Taipower system located in northern, central, and southern Taiwan are meticulously analyzed and utilized to verify the feasibility and practicability of cost allocation. [ABSTRACT FROM AUTHOR]

This paper presents a 5-bit flash analog-to-digital converter design using the 0.18-µm Taiwan Semiconductor Manufacturing Company's CMOS technology library. The designed system consists of 2 main blocks, a comparator array, and a digital decoder. The digital decoder contains a latch, 1-of-N decoder, and fat-tree encoder units. The 1-of-N decoder is implemented using 2 x 1 multiplexers. As a result, the active die area and the power consumption are reduced, in addition to an increase in the sampling frequency. The power supply voltage range for the overall system is ± 0.9 V. For testing purposes, a ramp signal of between -0.45 V and 0.7 V is applied to the converter input. The sampling frequency is 5 Gs/s. The simulation results include a maximum power consumption of 28 mW, integral nonlinearity values of between -0.65 least significant bits (LSB) and +0.01 LSB, differential nonlinearity values of between -0.3 LSB and +0.13 LSB, and an active die area of 0.1 mm². [ABSTRACT FROM AUTHOR]

Abstract: Taiwan is a high energy-importing nation with approximately 98% of our energy supplied by imported fuels in 2004. The energy conservation and/or energy efficiency improvement is becoming vital energy issues in the country. In this regard, cogeneration system or combined heat and power system used for the utilization of waste heat from energy and industrial sectors is thus becoming attractive due to the energy, economic and environmental policies for pursuing stable electricity supply, sustainable development and environmental pollution mitigation in Taiwan. The objective of this paper is to present an analysis of cogeneration system utilized as sustainable energy in the industrial sector in Taiwan. The description in the paper is thus summarized on an analysis of electricity supply/consumption and its sources from cogeneration system during the past two decades (1984–2004) and then centered on new/revised promotion legislation/regulations especially concerning cogeneration system in the measures of environmental protection and economic/financial incentives. Finally, we preliminarily present the results of environmental benefit analysis in the greenhouse gases reduction. Based on the data in 2004, it was found that the reduction benefits of carbon dioxide and nitrous oxide were estimated to achieve 3.488×107 and 650 metric tones, respectively. [Copyright &y& Elsevier]

Abstract: The research explores the potential effects of alternative regulatory policies for electricity market liberalisation on the investment behaviour and environmental performance of the electricity industry in Taiwan. The results provide insights into how the electricity market might evolve under the proposed reform scheme and other possible scenarios. This paper begins by reviewing the characteristics of the industry and how it has developed so far, and follows by studying the planned liberalisation agenda and the main purposes of the regulatory policies. Whether the liberalised electricity market will develop in a desirable direction is investigated by analysing investors’ aspirations for the market and their possible reactions to regulatory policies. The paper focuses on the investment decisions of the generation sector and concludes with assessments of the implications for security of supply, fuel diversity, electricity price and the environment. [Copyright &y& Elsevier]

The "318 Blackout Incident" at the Maanshan Nuclear Power Station on March 18, 2001, is considered to be the most serious event over the 24-year history of nuclear power generation in Taiwan. This paper simulates a special overvoltage phenomenon that occurred 4 h before the blackout event, which could have caused the incident. The simulation results almost coincide closely with the actual conditions recorded. We found two major low-frequency and ferroresonant overvoltages caused by the motors which acted as generators when they lost power supply, interacting with power-line capacitance and power transformers. Since overvoltages were present for a short period, the breaker insulation did not break down immediately but the defects were accumulated. A blackout eventually occurred 4 h later, when the power supplied to the 4.16-kV essential bus A changed over from the 161-kV system to the 345-kV system, due to damage in the incoming breaker insulation. [ABSTRACT FROM AUTHOR]

In this paper, a piezoelectric wave-energy converter (PWEC), consisting of a buoy, a frequency up-conversion mechanism, and a piezoelectric power-generator component, is developed. The frequency up-conversion mechanism consists of a gear train and geared-linkage mechanism, which converted lower frequencies of wave motion into higher frequencies of mechanical motion. The slider had a six-period displacement compared to the wave motion and was used to excite the piezoelectric power-generation component. Therefore, the operating frequency of the piezoelectric power-generation component was six times the frequency of the wave motion. The developed, flexible piezoelectric composite films of the generator component were used to generate electrical voltage. The piezoelectric film was composed of a copper/nickel foil as the substrate, lead–zirconium–titanium (PZT) material as the piezoelectric layer, and silver material as an upper-electrode layer. The sol-gel process was used to fabricate the PZT layer. The developed PWEC was tested in the wave flume at the Tainan Hydraulics Laboratory, Taiwan (THL). The maximum height and the minimum period were set to 100 mm and 1 s, respectively. The maximum voltage of the measured value was 2.8 V. The root-mean-square (RMS) voltage was 824 mV, which was measured through connection to an external 495 kΩ resistive load. The average electric power was 1.37 μW. [ABSTRACT FROM AUTHOR]

Due to the advance of dynamic random access memory (DRAM) technologies with the steadfast increase of density with aggressively scaled storage capacitors, the supply voltage has been lowered to under 1 V to reduce power consumption. The above progress has been accompanied by the increasingly difficult task of sensing cell data reliably. One of the essential methods to preserve sustainable data retention characteristic is to curtail the sub-threshold leakage current by using a negative voltage bias for the bulk of access transistors. This negative back-bias is generated by a back-bias voltage generator. This paper proposes a novel high-speed back-bias voltage (VBB) generator with a cross-coupled hybrid pumping scheme. The conventional circuit uses one fixed voltage to control the gates of discharge of the p-channel metal oxide semiconductor (PMOS) and transfer n-channel metal oxide semiconductor (NMOS), respectively. However, the proposed circuit adds an auxiliary pump, thereby able to control more aptly with a lower negative voltage when discharging and a higher positive voltage when transferring. As a result, the proposed circuit achieves a faster pump-down speed and higher pumping current at a lower supply voltage compared to conventional circuits. The H-simulation program with integrated circuit emphasis (HSPICE) simulation results with the Taiwan semiconductor manufacturing company (TSMC) 0.18 um process technology indicates that the proposed circuit has about a 20% faster pump-down speed at a supply voltage of voltage common collector (VCC) = 1.2 V and about 3% higher pumping current at VBB from −0.6 V to −1 V with the ability to generate a near 3% higher ratio of |VBB|/VCC at VCC = 0.6 V compared to conventional circuits. Hence, the proposed circuit is extremely suitable and promising for future low-power and high-performance DRAM applications. [ABSTRACT FROM AUTHOR]

Abstract: Driven by technology advances and demand for enhanced productivity, migration of wafer fabrication for DRAM (Dynamic Random Access Memory) toward increased wafer size has become the fast-growing trend in semiconductor industry. Taiwan accounts for about 18% of the total DRAM wafer production in the world. The energy use required for operating wafer fabrication plants (fabs) is intensive and has become one of the major concerns to production power reliability in the island. This paper characterizes the energy use in four 300 mm DRAM wafer fabs in Taiwan through performing surveys and on-site measurements. Specifically, the objectives of this study are to characterize the electric energy consumption and production of 300 mm DRAM fabs by using various performance metrics, including PEI ((production efficiency index), annual electric power consumption normalized by annual produced wafer area) and EUI ((electrical utilization index), annual electric power consumption normalized by UOP (units of production), which is defined as the product of annual produced wafer area and the average number of mask layers of a wafer). The results show that the PEI and EUI values are 0.743 kWh/cm2 and 0.0272 kWh/UOP, respectively. Using EUI in assessing energy efficiency of the fab production provides more consistent comparisons than using PEI alone. [ABSTRACT FROM AUTHOR]

The coevolutionary algorithm (CEA) based on the Lagrangian method is proposed for hydrothermal generation scheduling. The main purpose of hydrothermal generation scheduling is to minimize the overall operation cost and the constraints satisfied by scheduling the power outputs of all hydro and thermal units under study periods, given electrical load and limited water re- source. In the proposed method, a genetic algorithm is successfully incorporated into the Lagrangian method. The genetic algorithm searches out the optimum using multiple-path techniques and possesses the ability to deal with continuous and discrete variables. Regardless of the objective function characteristic the genetic algorithm does not have to modify the design rules and possesses the ability to go over local solutions toward the global optimal solution. The genetic algorithm can improve the disadvantages of the traditional Lagrangian method, which updates Lagrange multipliers according to the degree of system constraint violation by the gradient algorithm, and further searches out the global optimal solution. The developed algorithm is illustrated and tested on a practical Taiwan power system. Numerical results show that the proposed CEA based on the Lagrangian method is a very effective method for searching out the global optimal solution. [ABSTRACT FROM AUTHOR]

This paper investigates strategies to reduce CO2 emissions from the power sector of Taiwan. A multi-objective mix integer model for power generation strategy in Taiwan is proposed. A power supply problem with integer constraints on lowest power generation to meet the practical operation of power unit is also presented. This model can be used to plan future power units’ expansion strategy, as well as to study the effect of CO2 emission constraints. Further, this model is used to investigate optimal strategies for stabilizing CO2 emissions to the desired level from the power sector in Taiwan; these accounted for about 40% of CO2 emissions in the country in 2000. Real operational data from the Taiwan Power Company are used for testing the model effectiveness. In addition, recommendations are made for implementation. [Copyright &y& Elsevier]

A reasonable amount of spinning reserve is essential to satisfy system security constraints when the power system encounters a contingency. For isolated power systems, the influence of the system characteristics on spinning reserve requirements (such as load models, load variational characteristics, frequency sensitivity of loads) is more important than the reliability of individual units. The paper proposes a method that takes into consideration load variational characteristics, system load, load-frequency sensitivity factor and frequency operating standards to schedule spinning reserve requirements, which arc called reasonable spinning reserve requirements. The one-minute recovery frequency following a contingency would be a more appropriate measure of system security and would represent an enhanced frequency regulating reserve policy. To examine the merits of the proposed method, simulation runs were performed on the Taiwan Power System (TPS) and compared with the Taiwan Power Company (TPC) manual dispatch. [ABSTRACT FROM AUTHOR]

• Statistical and machine learning methods for imputing missing electric power data are studied. • Multiple missing feature values of each electric power data are considered. • The performance of different methods over the summer and non-summer season data is compared. • The imputation performances during the peak, off-peak, and semi-peak times are examined. Demand for electricity is gradually increasing in many countries. Efforts in related studies have been made for the application of data mining techniques over related electric power data for the development of more effective energy management systems. However, one major challenge is how to compensate for parts of the collected dataset, such as power consumption, voltage, or electric current that may be missing for a specific period of time. In the literature, several methods have been employed for imputation of the missing data, especially single feature value imputation. However, the performance of the different types of imputation methods, i.e. statistical and machine learning methods, for multiple missing features of electric power data has not been fully explored. Moreover, variations in their imputation performance during the summer/non-summer seasons and in the peak/off-peak/semi-peak times have not been investigated. In this paper, the performance of five well-known imputation methods for processing electric power data, two statistical methods, autoregressive integrated moving average (ARIMA) and linear interpolation (LI) models, and three machine learning methods, k-nearest neighbor (K-NN), multilayer perceptron (MLP), and support vector regression (SVR) is compared. The experimental results, based on electric power data for a two-year period in Taiwan, show that the machine learning methods generally perform better than the statistical ones, with K-NN and SVR performing the best. In particular, all of the imputation methods produced higher error rates during the summer season than the non-summer seasons. Moreover, the machine learning methods (especially K-NN) are better choices for the imputation of missing data during peak times, whereas the statistical methods (especially LI) are better for off-peak and semi-peak times. [ABSTRACT FROM AUTHOR]

The economic cost of electricity shortages provides valuable information for planners in setting economic reliability standards, determining pricing policy, load management strategies and curtailment policies in electric power system planning. This paper applies the Leontief input--output framework to account for the average economic impact of short-term electricity shortages on all industrial sectors. A case study for the economy of Taiwan using the latest available input-output Tables is included. The interrelated influences among sectors and the global effects incurred by the deficiency of electricity supply are analysed using this approach. [ABSTRACT FROM AUTHOR]

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Examines the electric current of the Le Blanc transformer of the railway system in Taiwan. Influence of impedance circuit on power supply voltage; Source of electric traction; Structure of the transformer.

This letter presents a simple criterion for reviewing balanced three-phase fault and unbalanced ground-fault current using the ratio of zero sequence impedance to positive sequence impedance as seen from the fault location, which can be employed to enhance the power system design and protection. The method has been verified by real power systems in Taiwan with satisfactory results. [ABSTRACT FROM AUTHOR]