http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Kwon, Yong-Cheol,Lee, Joohyun,Sul, Seung-Ki [Institute of Electrical and Electronic Engineers] 2019 IEEE transactions on industry applications Vol.55 No.2
<P>This paper analyzes the convergence of signal-injection sensorless control (SISC) especially for heavily saturated interior permanent-magnet synchronous motors (IPMSMs). In the analysis, it is revealed that the harmonic inductance and the operating current variation are critical factors in determining the operational limit of SISC. The clear boundary of SISC for an IPMSM can be obtained through the proposed convergence analysis. Based on this analysis, a control algorithm is proposed to extend the operational limit of SISC. With the proposed method, the torque capability under SISC can be maximized. Simulations and experiments are performed to verify the proposed method.</P>
Soo-Bin Kang,Min-Geun Choi,Dae-Yong Jeong,Young-Min Kong,Jungho Ryu Institute of Electrical and Electronic Engineers 2015 IEEE transactions on dielectrics and electrical in Vol. No.
<P>Antiferroelectric films of Sn doped Lead Lanthanum Zirconate-Titanate [(Pb, La)(Sn, Zr, Ti)O<SUB>3</SUB>, Sn-PLZT] with nano-grains were fabricated by aerosol-deposition (AD). The AD process produced highly dense films without visible pores. The polarization-electric field hysteresis loop and the phase transition behavior of PLZT with Sn doping into the B-sites were characterized. The grain sizes of the AD Sn-PLZT films, which were on the nano-scale, were controlled by the annealing temperature. Regardless of the compositions, the films with the nano-grains by the AD process showed less hysteretic behavior and larger stored energy. The Pb<SUB>0.97</SUB>La<SUB>0.02</SUB>(Zr<SUB>0.85</SUB>Sn<SUB>0.13</SUB>Ti<SUB>0.02</SUB>)O<SUB>3</SUB> (PL-0.13) film deposited by AD and annealed at 750 °C for 1 h showed an energy storage capacity and efficiency of 13.0 J/cm<SUP>3</SUP> and 78.9 %, respectively.</P>
Jae-Kyu Seong,Won Choi,Khan, Umer A.,Bang-Wook Lee,Gi-Jin Nam,Jeong-Tae Kim Institute of Electrical and Electronic Engineers 2015 IEEE transactions on dielectrics and electrical in Vol. No.
<P>In the design of DC superconducting cables, the electrical insulation design is a critical factor in the cable's performance and reliability. To evaluate the insulation design of DC superconducting cables, DC electric field analysis and experimental verifications should be performed. Wrapped polypropylene laminated paper (PPLP) tape has generally been used to insulate superconducting cable. During the wrapping process, butt gaps are inevitably introduced, and these are filled with liquid nitrogen (LN<SUB>2</SUB>) during normal operating conditions. Therefore, the insulation characteristics of the resulting combination of PPLP and liquid insulation should be carefully verified. The objective of this work was to determine the DC electric field transitions when a butt gap is present in a LN<SUB>2</SUB>/PPLP composite insulation system. DC electric field distribution and transition were simulated by using COMSOL Multiphysics<SUP>®</SUP> software. Also, to verify the characteristics of DC electric field transitions, two kinds of breakdown tests were performed: a ramp voltage breakdown test and a step voltage breakdown test. In both the experimental and analytical works, it was observed that the electric field distributions were totally different while the DC field transition. And, due to the different distributions of electric field, the breakdown characteristics of LN<SUB>2</SUB>/PPLP composite insulation systems could be altered.</P>
High Voltage Pulsed Power Supply Using IGBT Stacks
Jong-Hyun Kim,Byung-Duk Min,Shenderey, S.V.,Geun-Hie Rim Institute of Electrical and Electronic Engineers 2007 IEEE transactions on dielectrics and electrical in Vol.14 No.4
<P>High voltage pulsed power supply using IGBT (insulated gate bipolar transistor) stacks and pulse transformer for plasma source ion implantation is proposed. To increase voltage rating, twelve IGBTs are used in series at each IGBT stack and a step-up pulse transformer is utilized. To increase the current rating, the proposed system makes use of synchronized three pulse generator modules composed of diodes, capacitors and IGBT stacks. The proposed pulsed power supply uses semiconductor switches as main switches. Hence, the system is compact, and has semi-infinite lifetime. In addition, it has high flexibility in parameters such as voltage magnitude (10-60 kV), pulse repetition rate (PRR) (10-2000 pps), and pulse width (2-5 muS).</P>
Speed-Sensorless DTC-SVM for Matrix Converter Drives With Simple Nonlinearity Compensation
Lee, Kyo-Beum,Blaabjerg, Frede,Yoon, Tae-Woong [Institute of Electrical and Electronic Engineers] 2007 IEEE transactions on industry applications Vol.43 No.6
<P> This paper presents a new method to improve the sensorless performance of matrix converter drives using a parameter estimation scheme. To improve low-speed sensorless performance, the nonlinearities of a matrix converter drive such as commutation delays, turn-on and turn-off times of switching devices, and <SMALL>ON</SMALL>-state switching device voltage drop is modeled using <B><I>p</I></B>–<B><I>q</I></B>– <B><I>r</I></B> transformation and compensated using a reference current control scheme. To eliminate the input current distortion due to the input voltage unbalance, a simple method using <B><I>p</I></B>–<B><I>q</I></B>– <B><I>r</I></B> transformation is also presented. The proposed compensation method is applied for high performance induction motor drives using a 3-kW matrix converter system without a speed sensor. Experimental results are shown to illustrate the feasibility of the proposed strategy. </P>
Electrical and mechanical diagnosis of aging 600 V rated STP cables in a nuclear power plant
Kim, Kwangho,Shin, Jaeyoung,Kim, Byung-Sung,Nah, Wansoo,Lim, Chanwoo,Chai, Jangbom Institute of Electrical and Electronic Engineers 2017 IEEE transactions on dielectrics and electrical in Vol.24 No.3
<P>This paper proposes electrical and mechanical diagnostic methods to estimate the aging effects of 14 American wire gage (AWG) 600 V rated shielded twisted pair (STP) cables used in nuclear power plant. The cables were accelerated to be degraded in a dry oven using Arrhenius's equation, and the properties of healthy and degraded cables were estimated electrically and mechanically as well. S-parameters were measured using a vector network analyzer (VNA) and were used to assess the aging effects of the degraded cable. An effective modulus was also used as an aging indicator of the mechanical properties. An indenter was designed and fabricated to measure the effective modulus of aged cables. Both methods' results were compared and found to be effective for diagnosing the deterioration of the aging cables. Therefore, the proposed methods could be very useful for maintaining power cables in nuclear power plants.</P>
Compact design of high voltage switch for pulsed power applications
Appiah, G. N.,Jang, S. R.,Bae, J. S.,Cho, C. G.,Song, S. H.,Ryoo, H.J. Institute of Electrical and Electronic Engineers 2017 IEEE transactions on dielectrics and electrical in Vol.24 No.4
<P>Generally, for pulsed power applications with low jitter and high repetition rates, the use of semiconductor switches have replaced the traditional gap switches and thyratron circuits due to the limited lifetime of the thyratron and gap switches under such operating conditions. However, the limited ratings of these semiconductor switches require series and/or parallel stacking in order to handle high voltages and current levels associated with the discharge energy. Described in this paper is the design of a high voltage switch that uses a simple and reliable gate driver circuit for pulsed power application. In this design, the switch module is made up of insulated-gate bipolar transistor (IGBTs) and their gate driver circuits compactly fitted onto a single module. The ease by which the switch modules can be configured (series stacking and/or parallel stacking) to meet future load variations allows for flexible operation of this design. In addition, the detailed implementation of the gate driver circuit for reliable and easier synchronization of the switches, the simultaneous transfer of both signal and power for current boost are also described in this paper. A 120 nF capacitor bank energy was discharged using a configuration of the developed high voltage switch and a developed 15 kV, 1.5 kJ/s peak power capacitor charger, and by experimental results, the operation of the proposed circuit was verified to be effectively used as a switch for pulse discharging.</P>
Comparative study of pulse trigger and DC trigger circuit for xenon flash lamp drivers
Song, Seung-Ho,Cho, Chan-Gi,Park, Su-Mi,Park, Hyun-Il,Ryoo, Hong-Je Institute of Electrical and Electronic Engineers 2019 IEEE transactions on dielectrics and electrical in Vol.26 No.2
<P>This paper presents an investigation of trigger circuits for xenon flash lamp drivers from the viewpoint of breakdown voltage, high-voltage isolation, and reliability. A comparative study of pulse trigger and DC trigger circuits is provided, focusing particularly on the circuit structure of each driver for high voltage isolation. Two kinds of trigger circuits for xenon flash lamp drivers are developed with a 2.5 kW (500 V/5 A) simmer circuit for maintaining the xenon lamp ionization. The structure of each trigger circuit is the series trigger type to obtain the advantages of the isolation structure. The outputs of the pulse and DC trigger circuits are measured as 21 kV 1.8 μs half-sine wave pulse and above 10 kV DC, respectively. The tests of xenon lamp ignition and the results of the comparison are discussed. The results prove that the both developed trigger circuits can be effectively used as xenon flash lamp drivers.</P>
In-Service Monitoring of Stator-Slot Magnetic Wedge Condition for Induction Motors
Han, Sangwoo,Jung, Junyeong,Lee, Kun Wang,Lee, Sang Bin,Nandi, Subhasis,Kim, Byunghwan,Kang, Byunghee [Institute of Electrical and Electronic Engineers] 2016 IEEE transactions on industry applications Vol.52 No.4
<P>Stator-slot magnetic wedges are used instead of conventional epoxy glass wedges in large, high-output induction motors since the motor efficiency and power factor can be improved. However, cases of loose or missing magnetic wedges due to their weak mechanical strength have recently been increasingly reported. Although missing wedges can deteriorate motor performance and reliability, there is currently no test method accepted in the field for wedge quality assessment other than offline, disassembled visual inspection. In this paper, a new in-service method for monitoring the magnetic wedge condition in induction motors based on the negative-sequence information is proposed. The new method is developed based on the analysis of the dynamic model of the induction motor with missing magnetic slot wedges, derived in this paper. The proposed method is verified on a finite-element (FE) model of a 6.6-kV, 1850-kW induction motor. It is also verified experimentally on a 6.6-kV, 220-kW induction motor operating in the field with missing wedges (before and after rewedging), and on a 380-V, 5.5-kW induction motor with custom-built, removable magnetic wedges. It is shown that the proposed method can provide online detection of missing magnetic wedges, which can help reduce maintenance costs and risk of degradation in motor performance.</P>
Identification of Induction Motor Parameters at Standstill Based on Integral Calculation
Lee, Sang-Hoon,Yoo, Anno,Lee, Hak-Jun,Yoon, Young-Doo,Han, Byung-Moon [Institute of Electrical and Electronic Engineers] 2017 IEEE transactions on industry applications Vol.53 No.3
<P>This paper proposes an identification method for induction motor parameters at standstill using integral calculations. The rotor time constant and magnetizing inductance are identified. During the identification process, the induction motor to be tested is consistently excited according to a predetermined current reference. Using the predetermined current, the induction motor emulates the rated rotor flux and the rated slip condition, even at standstill. This method is based on an integral calculation so that the results are robust to measurement noise. Based on these features, the identification result of the proposed method is quite accurate, and the method shows excellent repeatability. Due to the simplicity of the proposed technique, this method can be easily applied to commercial inverter products. Simulation and experimental results confirm the effectiveness of the proposed method.</P>