Forecasting Day-ahead Electricity Price Using a Hybrid Improved Approach

Hu, Jian-Ming,Wang, Jian-Zhou The Korean Institute of Electrical Engineers 2017 Journal of Electrical Engineering & Technology Vol.12 No.6

Electricity price prediction plays a crucial part in making the schedule and managing the risk to the competitive electricity market participants. However, it is a difficult and challenging task owing to the characteristics of the nonlinearity, non-stationarity and uncertainty of the price series. This study proposes a hybrid improved strategy which incorporates data preprocessor components and a forecasting engine component to enhance the forecasting accuracy of the electricity price. In the developed forecasting procedure, the Seasonal Adjustment (SA) method and the Ensemble Empirical Mode Decomposition (EEMD) technique are synthesized as the data preprocessing component; the Coupled Simulated Annealing (CSA) optimization method and the Least Square Support Vector Regression (LSSVR) algorithm construct the prediction engine. The proposed hybrid approach is verified with electricity price data sampled from the power market of New South Wales in Australia. The simulation outcome manifests that the proposed hybrid approach obtains the observable improvement in the forecasting accuracy compared with other approaches, which suggests that the proposed combinational approach occupies preferable predication ability and enough precision.

Multi-Objective Optimization Model of Electricity Behavior Considering the Combination of Household Appliance Correlation and Comfort

Qu, Zhaoyang,Qu, Nan,Liu, Yaowei,Yin, Xiangai,Qu, Chong,Wang, Wanxin,Han, Jing The Korean Institute of Electrical Engineers 2018 Journal of Electrical Engineering & Technology Vol.13 No.5

With the wide application of intelligent household appliances, the optimization of electricity behavior has become an important component of home-based intelligent electricity. In this study, a multi-objective optimization model in an intelligent electricity environment is proposed based on economy and comfort. Firstly, the domestic consumer's load characteristics are analyzed, and the operating constraints of interruptible and transferable electrical appliances are defined. Then, constraints such as household electrical load, electricity habits, the correlation minimization electricity expenditure model of household appliances, and the comfort model of electricity use are integrated into multi-objective optimization. Finally, a continuous search multi-objective particle swarm algorithm is proposed to solve the optimization problem. The analysis of the corresponding example shows that the multi-objective optimization model can effectively reduce electricity costs and improve electricity use comfort.

A Study on New Power Business Model Using Power Information Technology

Bae, Sung-Hwan,Kim, Ja-Hee,Lim, Han-Seung The Korean Institute of Electrical Engineers 2010 Journal of Electrical Engineering & Technology Vol.5 No.3

The Korea Electric Power Corporation (KEPCO) recorded 2.9 trillion won deficit in the aftermath of the world financial crisis. KEPCO is trying to escape from the business crisis in every way; however, it is impossible to make huge profit by selling electricity alone. Overseas electrical utilities make profits by selling gas and heat along with electricity. However, it is difficult for KEPCO to enter the gas and the heat selling market because other public companies are already dealing with them. In this situation, improving the business is possible when KEPCO develops a new business model and creates added value using Korean advanced Power IT combined with electricity. This study shows a new business model using Power IT, based on a survey targeting managers in KEPCO branch office and electrical engineers in the field. We hope the new business model suggested in this study is adapted to the real field to create high value in the future.

Multistress Life Models of Epoxy Encapsulated Magnet wire under High Frequency Pulsating Voltage

Grzybowski, S.,Feilat, E.A.,Knight, P. The Korean Institute of Electrical Engineers 2003 KIEE International Transactions on Electrophysics Vol.3C No.1

This paper presents an attempt to develop probabilistic multistress life models to evaluate the lifetime characteristics of epoxy-encapsulated magnet wire with heavy build polyurethane enamel. A set of accelerated life tests were conducted over a wide range of pulsating voltages, temperatures, and frequencies. Samples of fine gauge twisted pairs of the encapsulated magnet wire were tested us-ing a pulse endurance dielectric test system. An electrical-thermal lifetime function was combined with the Weibull distribution of lifetimes. The parameters of the combined Weibull-electrical-thermal model were estimated using maximum likelihood estimation. Likewise, a generalized electrical-thermal-frequency life model was also developed. The parameters of this new model were estimated using multiple linear regression technique. It was found in this paper that lifetime estimates of the two proposed probabilistic multistress life models are good enough. This suggests the suitability of using the general electrical-thermal-frequency model to estimate the lifetime of the encapsulated magnet wire over a wide range of voltages, temperatures and pulsating frequencies.

An Innovative Solution for the Power Quality Problems in Induction Motor by Using Silica and Alumina Nano Fillers Mixed Enamel for the Coatings of the Windings

Mohanadasse, K.,Sharmeela, C.,Selvaraj, D. Edison The Korean Institute of Electrical Engineers 2015 Journal of Electrical Engineering & Technology Vol.10 No.4

Power quality has always been a concern of power engineers. Certainly an argument can be successfully made that most parts of power engineering have the ultimate objective to improve power quality. AC motors were widely used in industrial and domestic applications. Generally, AC motors were of two types: Induction and Synchronous motors. In motor many parameters like different load cycling, switching, working in hot weather and unbalances creates harmonics which creates major reasons for temperature rise of the motors. Due to high peak value of voltage, harmonics can weaken insulation in cables, windings and capacitors and different electronic components. Higher value of harmonics increase the motor current and decrease the power factor which will reduce the life time of the motor and increase the overall rating of all electrical equipments. Harmonics reduction of all the motors in India will save more power. Coating of windings of the motor with nano fillers will reduce the amount of harmonics in the motor. Based on the previous project works, actions were taken to use the enamel filled with various nano fillers for the coating of the windings of the different AC motors. Ball mill method was used to convert the micro particles of Al₂O₃, SiO₂, TiO₂, ZrO₂ and ZnO into nano particles. SEM, TEM and XRD were used to augment the particle size of the powder. The synthesized nano powders were mixed with the enamel by using ultrasonic vibrator. Then the enamel mixed with the nano fillers was coated to the windings of the several AC motors. Harmonics were measured in terms of various indices like THD, VHD, CHD and DIN by using Harmonic analyzer. There are many other measures and indices to describe power quality, but none is applicable in all cases and in many instances, these indices may hide more than they show. Sometimes power quality indices were used as a basis of comparison and standardization. The efficiency of the motors was increased by 5 – 10 %. The thermal withstanding capacity of the motor was increased by 5º to 15º C. The harmonics of the motors were reduced by 10 – 50%.

A Diesel Generator Model with Fluctuating Engine Torque Including Magnetic Saturation for Transient Analysis using XTAP

Sakamoto, Orie The Korean Institute of Electrical Engineers 2015 Journal of Electrical Engineering & Technology Vol.10 No.3

Diesel engine generators are widely used in the world, especially in remote site power systems as distributed generators. A weak distribution feeder with a small diesel engine may suffer from voltage and power fluctuations due to misfiring of the engine cylinder. In this study, new generator model with example engine torque was developed for the electromagnetic transient analysis program for power systems named XTAP. The configuration and verification results of the developed model are presented in the paper. The model is considered to be useful for analyses of small power systems with those diesel engines.

Measurement of III-V Compound Semiconductor Characteristics using the Contactless Electroreflectance Method

Yu, Jae-In,Choi, Soon-Don,Chang, Ho-Gyeong The Korean Institute of Electrical Engineers 2011 Journal of Electrical Engineering & Technology Vol.6 No.4

The electromodulation methods of photoreflectanceand the related technique of contactless electroreflectance(CER) are valuable tools in the evaluation of important device parameters for structures such as heterojunction bipolar transistors, pseudomorphic high electron mobility transistors, and quantum dots(QDs). CER is a very general principle of experimental physics. Instead of measuring the optical reflectance of the material, the derivative with respect to a modulating electric field is evaluated. This procedure generates sharp, differential-like spectra in the region of interband (intersubband) transitions. We conduct electric-optical studies of both GaAs layers and InAs selfassembled QDs grown by molecular beam epitaxy. Strong GaAsbandgap energy is measured in both structures. In the case of lnAs monolayers in GaAs matrices, the strong GaAsbandgap energy is caused by the lateral quantum confinement.

Practical Methodology of the Integrated Design and Power Control Unit for SHEV with Multiple Power Sources

Lee, Seongjun,Kim, Jonghoon The Korean Institute of Electrical Engineers 2016 Journal of Electrical Engineering & Technology Vol.11 No.2

Series hybrid electric vehicles (SHEVs) having multiple power sources such as an engine- generator (EnGen), a battery, and an ultra-capacitor require a power control unit with high power density and reliable control operation. However, manufacturing using separate individual power converters has the disadvantage of low power density and requires a large number of power and signal cable wires. It is also difficult to implement the optimal power distribution and fault management algorithm because of the communication delay between the units. In order to address these concerns, this approach presents a design methodology and a power control algorithm of an integrated power converter for the SHEVs powered by multiple power sources. In this work, the design methodology of the integrated power control unit (IPCU) is firstly elaborately described, and then efficient and reliable power distribution algorithms are proposed. The design works are verified with product-level and vehicle-level performance experiments on a 10-ton SHEV.

E-H Mode Transition Properties of Cylindrical ICP Hg:Kr

Yang Jong-Kyung,Pack Kwang-Hyun,Lee Jong-Chan,Park Dae-Hee The Korean Institute of Electrical Engineers 2005 KIEE International Transactions on Electrophysics Vol.5C No.3

In this paper, we designed a cylindrical type light source having an electromagnetic principle of inductively coupled plasma, and measured its electrical-optical properties. Using the transformer principle, an electrically equivalent circuit cylindrical type light source was analyzed. According to the parameters of electromagnetic induction, which were diameter of coil with cpO.3$\~$ 1.2mm, number of turns with 4$\~$ 12 turns, distance with 40$\~$ l20mm and RF power with 10$\~$ 150W, the electrical .md optical properties were measured. When the diameter of the coil was cp0.3mm, number of turns was 8 and distance was 40mm, and the maximum brightness of 29,730 cd/m$^{2}$ was shown with RF power l50W. The relationship between electromagnetic induction and plasma discharges was demonstrated using the mode transition from E-mode to H-mode

Rotor Speed-based Droop of a Wind Generator in a Wind Power Plant for the Virtual Inertial Control

Lee, Jinsik,Kim, Jinho,Kim, Yeon-Hee,Chun, Yeong-Han,Lee, Sang Ho,Seok, Jul-Ki,Kang, Yong Cheol The Korean Institute of Electrical Engineers 2013 Journal of Electrical Engineering & Technology Vol.8 No.5

The frequency of a power system should be kept within limits to produce high-quality electricity. For a power system with a high penetration of wind generators (WGs), difficulties might arise in maintaining the frequency, because modern variable speed WGs operate based on the maximum power point tracking control scheme. On the other hand, the wind speed that arrives at a downstream WG is decreased after having passed one WG due to the wake effect. The rotor speed of each WG may be different from others. This paper proposes an algorithm for assigning the droop of each WG in a wind power plant (WPP) based on the rotor speed for the virtual inertial control considering the wake effect. It assumes that each WG in the WPP has two auxiliary loops for the virtual inertial control, i.e. the frequency deviation loop and the rate of change of frequency (ROCOF) loop. To release more kinetic energy, the proposed algorithm assigns the droop of each WG, which is the gain of the frequency deviation loop, depending on the rotor speed of each WG, while the gains for the ROCOF loop of all WGs are set to be equal. The performance of the algorithm is investigated for a model system with five synchronous generators and a WPP, which consists of 15 doubly-fed induction generators, by varying the wind direction as well as the wind speed. The results clearly indicate that the algorithm successfully reduces the frequency nadir as a WG with high wind speed releases more kinetic energy for the virtual inertial control. The algorithm might help maximize the contribution of the WPP to the frequency support.