권호 표지

전기학회논문지 (The Transactions of The Korean Institute of Electrical Engineers) (The Transactions of The Korean Institute of Electrical Engineers)

대한전기학회 (The Korean Institute of Electrical Engineers)

  • 월간
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  • 1975-8359(pISSN)
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  • 2287-4364(eISSN)

Aim & Scope

The first issue of The Transactions of the Korean Institute of Electrical Engineers(KIEE) was in October 1948. The Transactions of the KIEE is a monthly periodical published on the 1st day of each month. KIEE is an official publication of the Korean Institute of Electrical Engineers. The aim of the journal is to publish the highest quality manuscripts dedicated to the advancement of electrical engineering technologies. The Journal contains papers related to electrical power engineering, electrical machinery and energy conversion systems, electro-physics and application, information and controls, as well as electrical facilities. Currently, KIEE Transactions is divided into: “A” Sector (Power Engineering); “B” Sector (Electrical Machinery and Energy Conversion System); “C” Sector (Electro-physics and Application); “D” Sector (Information and Control); and “E” Sector (Electrical Facilities). With an aim to collect and publish outstanding scientific papers related to electrical engineering, the topics of papers published in KIEE Transactions are further divided into: power systems, transmission and distribution systems, electric power system economics, micro-grid, power system protection and automation, pumped-storage hydro power generation and electric energy storage systems in the “A” Sector; electrical equipment and appliances, power electronics, electrical traffic systems, new and renewable energy systems, eco-friendly electric power equipment, super-conductive equipment and E-mobility in the “B” Sector; electrical materials and semiconductors, smart large power and high voltage technology, optoelectronics and electromagnetic waves, Micro Electro Mechanical Systems (MEMS), and power asset risk management in the “C” Sector; instrumentation and control (I&C), robotics and automation, computer intelligence and intelligence systems, signal processing and embedded systems, autonomous moving object information processing, and biomedical engineering in the “D” Sector; and engineering and supervision, construction technology, power distribution system diagnosis, safety technology, electric railroad, technical standards, LVDC Facility, electric Facility fusion, etc. in the “E” Sector

http://www.trans.kiee.or.kr/ KSCI KCI SCOPUS

제67권7호

  1. 조규정;김지수;송진솔;신재윤;김동현;김철환 809
    https://doi.org/10.5370/KIEE.2018.67.7.809 PDF KSCI
    Distributed generations (DGs) using renewable energy resources in power systems have been widely integrated, and many of these DGs have intermittency. DGs can significantly affect the overall voltage profile of the system through the reactive power control for a voltage support. Therefore, in the planning stage of the optimal operation and dispatch of voltage regulation devices, DGs' hosting capacity with the reactive power control scheme should be considered. In this paper, we model the IEEE 34-bus test feeder, including all essential equipment. An optimization method is utilized to determine the optimal siting and operation of the voltage regulation devices in the presence of DGs with reactive power control scheme. Finally, we compare the optimal results of the each case to analyze the relationship among the hosting capacity of the DGs and voltage regulation devices operation.
  2. 신훈철;한수경;유준수;조수환 816
    https://doi.org/10.5370/KIEE.2018.67.7.816 PDF KSCI
    The Auto-synchronizer is essential equipment for synchronizing a generator to the power system. It is performing that measurement of the magnitude, frequency and phase of the voltage signal of the power system and generator. It is important to select the appropriate measurement algorithm for preventing various problem such as mechanical stress and Electrical problem. Teager Energy Operator(TEO) and Discrete separation algorithm(DESA) is measurable the instantaneous parameters of a sine wave using 5 samples and can be measured at a fast and with a simple operation. Therefore it has many advantages in measuring the parameters. In this paper, it confirmed measurement results using matlab simulations when there are synchronized in order of frequency, magnitude. Also it presented methods using digital filters and sample intervals to improve accuracy.
  3. 최홍열;최성식;강민관;노대석 824
    https://doi.org/10.5370/KIEE.2018.67.7.824 PDF KSCI
    According to the government's policy to demonstrate and expand the renewable energy sources, distributed generators such as PV and WP are installed and operated in distribution systems. However, there are many issues related to power quality problems including over voltage and under voltage of customers. In order to overcome these problems, the electric power company have installed a step voltage regulator (SVR) in primary feeders interconnected with distributed generators, and also have established the technical guidelines for the distributed generators to stabilize the customer voltages in distribution systems. However, it is difficult to maintain the customer voltages within allowable limit. Therefore, this paper reviews the problems of voltage control by SVR in a distribution systems interconnected with a large amount of PV systems, and proposes characteristics of operating range and voltage control limit of the small hydropower generators. Also, with the estimation of the influence to the power system voltages from the voltage control mode of generators, this paper proposes the optimal voltage control algorithm of the small hydropower generators. By programming the proposed algorithm into control simulator of exciter, it is confirmed that the proposed algorithm can contribute the voltage stabilization in distribution systems interconnected with large scaled PV systems.
  4. 공은경;손진만 833
    https://doi.org/10.5370/KIEE.2018.67.7.833 PDF KSCI
    This paper presents an analysis and the methodology of optimal operation strategy of the ESS(Energy Storage System) for reduce electricity charges. Electricity charges consist of a basic charge based on the contract capacity and energy charge according to the power usage. In order to use electrical energy at minimal charge, these two factors are required to be reduced at the same time. QP(Quadratic Programming) is appropriate for minimization of the basic charge and LP(Linear Programmin) is adequate to minimize the energy charge. However, the integer variable have to be introduced for modelling of different charge and discharge efficiency of ESS PCS(Power Conversion System), where MILP(Mixed Integer Linear Programming) can be used. In this case, the extent to which the peak load savings is accomplished should be assumed before the energy charge is minimized. So, to minimize the electricity charge exactly, optimization is sequentially performed in this paper, so-called the Two Stage Hybird optimization, where the extent to which the peak load savings is firstly accomplished through optimization of basic charge and then the optimization of energy charge is performed with different charge and discharge efficiency of ESS PCS. Finally, the proposed method is analyzed quantitatively with other optimization methods.
  5. 구정회;최장영 840
    https://doi.org/10.5370/KIEE.2018.67.7.840 PDF KSCI
    BLDC motor is widely used as a servo motor due to high efficiency, high power density, low inertia, and low maintenance. However, BLDC motor generally needs position and velocity sensors to control actuation system. Usually, analog tachometers and encoders have been used for velocity feedback sensors. However, using these types of sensors have problems such as the cost, space, and malfunction. So, This paper is to propose a new velocity measurement method using linear hall-effect and enhanced differentiator for BLDC motor. In order to verify the feasibility of the proposed method, several simulations and experiments are performed. It is shown that the proposed velocity measurement method can satisfy the requirements without using of velocity sensor.
  6. 노찬;김재창;곽상신 846
    https://doi.org/10.5370/KIEE.2018.67.7.846 PDF KSCI
    In this paper, an improved model predictive control (MPC) method is proposed, which reduces the amount of calculations caused by the increased number of candidate voltage vectors with the increased voltage level in multi-level inverters. When the conventional MPC method is used for multi-level inverters, all candidate voltage vectors are considered to predict the next-step current value. However, in the case that the sampling time is short, increased voltage level makes it difficult to consider the all candidate voltage vectors. In this paper, the improved MPC method which can get a fast transient response is proposed with a small amount of the computation by adding new candidate voltage vectors that are set to find the optimal vector. As a result, the proposed method shows faster transient response than the method that considers the adjacent vectors and reduces the computational burden compared to the method that considers the whole voltage vector. the performance of the proposed method is verified through simulations and experiments.
  7. 맹주철;조문택;윤중락 854
    https://doi.org/10.5370/KIEE.2018.67.7.854 PDF KSCI
    This paper describes the characteristics of a hybrid supercapacitor module for power quality stabilization. Hybrid supercapacitor is an promising energy storage device that positioned between conventional EDLC and Li-ion battery. A cylindrical 7500F hybrid supercapacitor ($60{\times}138mm$) was assembled by using the $Li_4Ti_5O_{12}$ electrode as an anode and activated carbon as a cathode. Considering the ESR and efficiency has been designed to module with 41.6F 480V design results in 180 series combination. In order to determine the characteristics of the hybrid supercapacitor module for power system, hybrid supercapacitor cells were connected in series with active balancing circuit. As a result of measuring the 50kw UPS, it was discharged at the current of 104A~143A during the discharge in the voltage range of 350V~480V, and the compensation time at discharge was measured to be about 30s. These results can be used to stabilization of power quality by applying hybrid supercapacitor module.
  8. 민우민;강종민;김형규;박준도;황보승 860
    https://doi.org/10.5370/KIEE.2018.67.7.860 PDF KSCI
    The signal of space charge distribution measured in polymer insulating materials by the PEA has some noises due to the system circuits and the ringing phenomena in the sensor of PVDF and so on forth. It's magnitude mainly depends on the thickness of the insulation material, and it is also affected by the attenuation and dispersion when traveling in a dielectric material. In order to make it reliable, the correcting process for the signal is essential. In this study, we proposed the new deconvolution process on the measured signal of space charge distribution in the flat XLPE insulator, and developed a new signal processing algorithm. Using this, we could improve the reliability of the measured signal much and analyze the effects of space charge clearly in materials.
  9. 이민기;서기성 865
    https://doi.org/10.5370/KIEE.2018.67.7.865 PDF KSCI
    A machine vision based industrial inspection includes defects detection and classification. Fast inspection is a fundamental problem for many applications of real-time vision systems. It requires little computation time and localizing defects robustly with high accuracy. Deep learning technique have been known not to be suitable for real-time applications. Recently a couple of fast region-based CNN algorithms for object detection are introduced, such as Faster R-CNN, and YOLOv2. We apply these methods for an industrial inspection problem. Three CNN based detection algorithms, VOV based CNN, Faster R-CNN, and YOLOv2, are experimented for defect detection on metal surface. The results for inspection time and various performance indices are compared and analysed.
  10. 조영완 871
    https://doi.org/10.5370/KIEE.2018.67.7.871 PDF KSCI
    In this paper, we propose a triple nested PID control scheme for stable hovering of a quadrotor and propose a complementary filter based sensor fusion technique to improve the performance of attitude, altitude and velocity measurement. The triple nested controller has a structure in which a double nested attitude controller that has the angular velocity PD controller in inner loop and the angular PI controller in outer loop, is nested in a velocity control loop to enable stable hovering even in the case of disturbance. We also propose a sensor fusion technique by applying a complementary filter in order to reduce the noise and drift error included in the acceleration and gyro sensor and to measure the velocity by fusing image, gyro, and acceleration sensor. In order to verity the performance, we applied the proposed control and measurement scheme to hovering control of quadrotor.
  11. 김덕규;김민정;정성윤 878
    https://doi.org/10.5370/KIEE.2018.67.7.878 PDF KSCI
    This paper proposes a method for transmitting instruction between vehicles in a moving situation using RC Car having camera. Information of preceding RC Car was transmitted by LED using Optical Camera Communication(OCC). Rear RC Car follows the preceding one by analyzing transmitted OCC data based on image processing. Through this procedure, the information reception ratio according to the distance change of two RC Cars is confirmed. Through experiments, we showed that our proposed scheme enables the possibility of vehicle platooning.
  12. 최훈 884
    https://doi.org/10.5370/KIEE.2018.67.7.884 PDF KSCI
    In this paper, we propose an automatic earthquake P-wave detection algorithm based on the variations of the impact momentum derived from the seismic acceleration signals. The amount of change in the impact momentum induced by the acceleration refers to the influence of buildings or facilities on the earthquake, The proposed algorithm can effectively detect the seismic P-wave by simultaneously considering the amplitude and the frequency change of the seismic wave when the earthquake occurs. Computer simulations using the observed seismic signals were performed to evaluate the validity of the induced impact momentum variation and the superiority of the proposed algorithm.
  13. 백현재;조재걸 892
    https://doi.org/10.5370/KIEE.2018.67.7.892 PDF KSCI
    Due to population aging, an increase in the number of patients with chronic illnesses, and an increase in the number of single-person households, monitoring of health status in everyday life without the need for a hospital has become very important. For this reason, researches on various health care devices have been attempted, among which wearable devices are attracting much attention. In this paper, we propose a new ring-type wearable device for next generation healthcare. On the inner side of the ring, a metal electrodes for GSR measurement and an optical sensor for measurement of pulse wave signals of two wavelengths of red and near-infrared light were mounted. In addition, it was equipped with an acceleration sensor, and information about the degree of motion could be obtained. In this paper, it is shown that a health monitoring device can be implemented in the form of a ring, and the measured signals can be used to calculate heart rate, oxygen saturation, sleep time and sleep efficiency. Through the advanced algorithm, it is expected that we can extract various health information, especially sleep related health information by using the ring device, and it is also expected that it can contribute to the implementation of wearable healthcare effectively.
  14. 최병훈 898
    https://doi.org/10.5370/KIEE.2018.67.7.898 PDF KSCI
    A novel heart beat interval estimation algorithm is presented based on parabola approximation method. This paper presented a two-step processing scheme; a first stage is finding R-peak in the Electrocardiogram (ECG) by Shannon energy envelope estimator and a secondary stage is computing the interpolated peak location by parabola approximation. Experimental results show that the proposed algorithm performs better than with the previous method using low sampled ECG signals.
  15. 진태석 903
    https://doi.org/10.5370/KIEE.2018.67.7.903 PDF KSCI
    We propose laser scanner sensor system based walking pattern and tracking method of multiple human. This system uses laser scanners sensors and is applicable to wide and crowded area such as hospital and medical care center. The primary objective of this research is to promote the development of robust, repeatable and transferable software for security system that can automatically detect, track and follow people in public area. We developed the method of human identification for this system. Our method is following: 1. Best-walking pattern data are obtained by the help of human position and direction data obtained by laser scanners. 2. Human identification is conducted by calculating the correlation between the step length of walking human. It becomes possible to conduct human identification even in crowded scenes by estimating the movements of waling human' feet are periodic. In the experiment in the station, some effectiveness of this method became clear.
  16. 강병권;최순;김재민;강현주;민세동 910
    https://doi.org/10.5370/KIEE.2018.67.7.910 PDF KSCI
    In this paper, we developed a shoulder rehabilitation exercise device and monitoring system to remotely provide rehabilitation system for the ones who need shoulder exercises including the patients with rotator cuff rupture. In order to evaluate the severity of shoulder muscle injury, a total of 4 shoulder rehabilitation exercises ((3) shoulder abduction, (2) shoulder flexion, (3) shoulder abduction with elbow flexion, (4) shoulder extension with elbow flexion) were selected and instructed to be performed with a 3 kg dumbbell for 5 times. For EMG (electromyogram) signal analysis, each subject's maximum voluntary contraction (MVC) was measured. EMG signals reflect the activation level of contracting muscles during dynamic exercises. Six participants' muscle activation levels in posterior deltoid, middle deltoid, upper trapezius, and infraspinatus were measured and compared. The mean power spectrum values in the time and frequency domains were compared between two age-matched groups (20s and 50s). The results showed lower muscle activation in the elderly subjects (n=3) compared to that of the ones in their twenties (n=3).
  17. 이성수;이강휘;김상민;이혁재;이병헌;김경섭;이정환 917
    https://doi.org/10.5370/KIEE.2018.67.7.917 PDF KSCI
    High blood pressure causes various cardiovascular diseases and is associated with mortality. Periodic self-monitoring and recording of blood pressure is very helpful in preventing the occurrence of secondary diseases caused by hypertension. However, existing cuff-type blood pressure monitors have many limitations. As an alternative of that, a method of estimating the blood pressure by measuring the velocity change of the blood flow using the photo plethysmography is widely known. However, photo plethysmography have a low correlation with blood flow. So, we will propose an algorithm for estimating blood pressure using the relationship between velocity change of blood flow measured by magnetic field instead of photo plethysmography and electrocardiogram. For this purpose, First, we analyzed the correlation between photo plethysmography and magneto plethysmography. the correlation between MPG and PPG was r = 0.9449. Second, we compared estimated blood pressure and measured blood pressure. In the four experiment each result was r = 0.5737, r = 0.7863, r = 0.5669, and r = 0.7445.
  18. 김동현;조현종 928
    https://doi.org/10.5370/KIEE.2018.67.7.928 PDF KSCI
    Nowadays, gastropathy is a common disease. As endoscopic equipment are developed and used widely, it is possible to provide a large number of endoscopy images. Computer-aided Diagnosis (CADx) systems aim at helping physicians to identify possibly malignant abnormalities more accurately. In this paper, we present a CADx system to detect and classify the abnormalities of gastric lesions which include bleeding, ulcer, neuroendocrine tumor and cancer. We used an Inception module based deep learning model. And we used data augmentation for learning. Our preliminary results demonstrated promising potential for automatically labeled region of interest for endoscopy doctors to focus on abnormal lesions for subsequent targeted biopsy, with Az values of Receiver Operating Characteristic(ROC) curve was 0.83. The proposed CADx system showed reliable performance.
  19. 장봉환;박인호;남현도;김경호 934
    https://doi.org/10.5370/KIEE.2018.67.7.934 PDF KSCI
    Recently, there have been a lot of sleepy driving accidents. In this study, we conducted a preliminary study for detecting drowsiness using posture and image processing technology. We used pressure sensors to study posture. We also investigated the possibility of drowsy recognition using histogram. As a result of the experiment, it was possible to distinguish positions through pressure sensors. Also, it was confirmed that the drowsiness phenomenon can be distinguished by using the histogram.
  20. 김경현;남현도;김경호 940
    https://doi.org/10.5370/KIEE.2018.67.7.940 PDF KSCI
    In this study, we make a study on a system to determine a person's sitting posture by measuring the distribution of pressure in the floor of a chair or in a cushion using pressure sensors. If the wrong sitting posture is detected, a warning message is given through the vibration motor in real time to correct the imbalance of the wrong habits and posture, and prevent Bulging disc or Herniated disc.
  21. 김상민;이강휘;이성수;이혁재;이병헌;김경섭;이정환 946
    https://doi.org/10.5370/KIEE.2018.67.7.946 PDF KSCI
    Photo-plethysmography (PPG), which measures changes in the peripheral blood flow of a human body using difference in absorption rate of light, is a measurement method that is studied and used in clinical and various applications due to its simple circuit configuration and measurement convenience. Magneto-plethysmography (MPG), which is newly developed by our team, is a method of measuring changes in the conductivity of biological tissues by using a eddy current induced by a time-varying magnetic field, and is not subject to optical interference. In this study, we investigated the detection characteristics of MPG according to the change of the conductivity of the object and fluid to be measured by simultaneously measuring PPG and MPG. In order to control the speed of fluid known in advance, a blood flow simulator was implemented and used. The fluid used in the experiment was general mineral water and physiological saline (0.9% NaCl) solution. Experimental results show that the amplitude change of the measured PPG was 0.3% in normal water and saline solution, and that of MPG was 77.3%. Therefore, it is considered that the magneto-plethysmography (MPG) has a strong correlation with the conductivity of the fluid.
  22. 박종진 954
    https://doi.org/10.5370/KIEE.2018.67.7.954 PDF KSCI
    In this paper, a chatbot for emotional stress recognition and management using rule-based method and NLP is designed and developed to tackle various emotional stresses of people through questionnaire. For this, Dialogflow as open chatbot development platform and Facebook messenger as chatting platform are used. We can build natural and resourceful conversational experiences through predefined questions by using powerful tools of Dialogflow, and can use developed chatbot on the Facebook page messenger. Developed chatbot perceives emotional stresses of user by user-input which is either text or choice of predefined answer. It also gives user questions according to the user's feeling, and assess the strength of the emotional stresses, and provide a solution to the user. Further research can improve the developed chatbot by using open Korean NLP library and database of emotions and stresses.
  23. 석현석;신항식 962
    https://doi.org/10.5370/KIEE.2018.67.7.962 PDF KSCI
    In this study, we developed novel indicators to assess postoperative pain based on PPG derivative waveform. As the candidate indicator of postoperative pain assessment, the time from the start of beating to the n-th peak($T_n$) and the n-th peak amplitude($A_n$) of the PPG derivative were selected. In order to verify derived indicators, each candidate indicator was derived from the PPG of 78 subjects before and after surgery, and it was confirmed whether significant changes were observed after surgery. Logistic classification was performed with each proposed indicator to calculate the pain classification accuracy, then the classification performance was compared with SPI(Surgical Pleth Index, GE Healthcare, Chicago, US). The results showed that there were significant differences(p < 0.01) in all indicators except for $T_3$ and $A_3$. The coefficient of variation(CV) of every time-related indicators were lower than the CV of SPI(30.43%), however, the CV in amplitude-related parameters were higher than that of SPI. Among the candidate indicators, amplitude of the first peak, $A_1$, showed that highest accuracy in post-operative pain classification, 68.72%, and it is 15.53% higher than SPI.
  24. 박현상;김현영;김화선 969
    https://doi.org/10.5370/KIEE.2018.67.7.969 PDF KSCI
    The purpose of this study is to develop a healthcare service based on standard protocol and information communication technology for mother's sustainable postpartum care. The developed service was consisted of a client area where mothers measure, manage and transmit their vital signs using their own smartphone and personal health devices, and a server area that manages and shares with the received mother's vital signs and the results of examination results and personal health records. The client area collects vital signs through the IEEE 11073 Personal Health Device (PHD) using the m-health application of the previous study and Continua Health alliance certified personal health devices and transfers to Health Level Seven (HL7) V2.4, Continuity of Care Record (CCR) and Continuity of Care Document (CCD). The server area consists of a mobile web that manages and shares the HL7 Fast Healthcare Interoperability Resources (FHIR)-compliant personal health records to ensure interoperability of examination results, and a mobile web where the postpartum caregiver enters and manages the results of the mother's examination results and provides it to the mother. In this way, the healthcare service of this study securing continued exchanges between the mother and postpartum caregiver improves the quality of life of the mother not only to satisfy the needs of the mother who was discharged but also through self-management and postpartum. In the future, we will conduct a study applying mothers and postpartum caregiver after approval of a clinical trail at a university hospital to evaluate developed healthcare services.
  25. 박영식;나경민;박영 976
    https://doi.org/10.5370/KIEE.2018.67.7.976 PDF KSCI
    The traction power system is configured to transmit electricity to the vehicles through mechanical contact between the OCL (Overhead Contact Line) and the pantograph. The system measures the current collection performance of the OCL, or the OCL installation condition is examined through maintenance for commercial operation. Maintenance continues to check the conditions through visual inspection by walking and inspection vehicles. The current collection performance is divided into the percentage of arcing(%), the contact force, and the uplift. The percentage of arcing is composed of a vision based system and used to verify the performance of a new OCL. However, it is not always possible to measure the current collection performance during commercial operation, and maintenance based on human resources can not be replaced. This paper presents the minimum performance condition of video devices in the current collection system of commercial vehicles. In addition, a continuous arcing was measured, and current collection performance was examined on the traction power system at the 250 km/h. It was analyzed with a minimum duration of arc of 1 ms. The frame rate is then shown by comparing the number of frames in the image at the time intervals of the number of the arcing. It is expected that the result of this study can be used for examining the minimum performance of video devices depending on their purpose.
  26. 박상용;최효상 981
    https://doi.org/10.5370/KIEE.2018.67.7.981 PDF KSCI
    AC(alternating current) CB(circuit breaker) at the fault occurred in the existing AC distribution system is limiting the fault current through zero cross-point. However, DC(direct current) CB does not have zero cross-point. Therefore, arc occurred by on-off operation of DC CB is very huge. Nowadays, many research team are studying the way to decrease breaking time, which is one of the essential conditions in DC CB. We suggested novel arc-induction type DC CB in this paper. The proposed arc-induction type DC CB is composed of the mechanical Arc ring and DC CB. We confirmed the operation of arc-induction type DC CB through the HFSS(High Frequency Structure Simulator) 3D simulation program and performed the experiment for operation characteristics. Results showed that arcing time of the arc-induction type DC CB by using induction ring was faster than existing mechanical DC CB. On the transient system, we confirmed stable operation characteristics of the arc-induction type DC CB through the simulation and experimental results. We expect that the proposed arc-induction type DC CB technology is will go to stay ahead of the existing DC CB technology.