• Title/Summary/Keyword: Balanced Power

Search Result 552, Processing Time 0.028 seconds

Current Control Scheme of High Speed SRM Using Low Resolution Encoder

  • Khoi, Huynh Khac Minh;Ahn, Jin-Woo;Lee, Dong-Hee
    • Journal of Power Electronics
    • /
    • v.11 no.4
    • /
    • pp.520-526
    • /
    • 2011
  • This paper presents a balanced soft-chopping circuit and a modified PI controller for a high speed 4/2 Switched Reluctance Motor (SRM) with a 16 pulse per revolution encoder. The proposed balanced soft-chopping circuit can supply double the switching frequency in the fixed switching frequency of power devices to reduce current ripple. The modified PI controller uses maximum voltage, back-emf voltage and PI control modes to overcome the over-shoot current due to the time delay effect of current sensing. The maximum voltage mode can supply a fast excitation current with consideration of the hardware time delay. Then the back-emf voltage mode can suppress the current over-shoot with consideration of the feedback signal delay. Finally, the PI control mode can adjust the phase current to a desired value with a fast switching frequency due to the proposed balanced soft-chopping technology.

The Design on a Wideband Active Printed Dipole Antenna using a Balanced Amplifier

  • Lee, Sung-Ho;Kwon, Se-Woong;Lee, Byoung-Moo;Yoon, Young-Joong;Song, Woo-Young
    • Journal of electromagnetic engineering and science
    • /
    • v.2 no.2
    • /
    • pp.112-116
    • /
    • 2002
  • In this paper, the active integrated antenna(AIA) using a wideband printed dipole antenna and a balanced amplifier is designed and fabricated. The proposed active printed dipole antenna has characteristics of easy matching, wide bandwidth and higher output power To feed balanced signal to printed dipole, a Wilkinson power divider and delay lines are used. The measured result shows that, at 6 GHz center frequency, the impedance bandwidth is 22 % (VSWR < 2), 3 dB gain bandwidth is 28 %, the maximum gain is 14.77 dBi, and output power at P1 dB point is 23 dBm.

Parallel Operation of Three-Phase Four wire UPS using Droop Control (Droop Control을 이용한 3상 4선식 UPS의 병렬운전)

  • Kim, Hyunseob;Han, Jungho;Song, Joong-Ho
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.27 no.4
    • /
    • pp.88-95
    • /
    • 2013
  • A new droop control method which can be applied to 3-phase 4-wire uninterruptible power supply is proposed in this paper. The droop control method for parallel operation is very attractive one as UPS parallel operation can be carried out without any data communication devices provided among UPS systems connected, but it reportedly shows a PnP(plug-and-play) problem. A basic reason why a circulating current could flow among parallel-connected UPS systems is clearly investigated as well when droop-controlled-ups systems are operated in the manner of PnP. The proposed algorithm is deduced from the investigated result and is basically structured to keep a balanced frequency and balanced voltage profile against power variation. This paper shows that balanced parallel operation of droop control method can be obtained under unbalanced load as well as balanced load conditions when PnP operation is needed and load change occurs.

Stability and parameters influence study of fully balanced hoist vertical ship lift

  • Cheng, Xionghao;Shi, Duanwei;Li, Hongxiang;Xia, Re;Zhang, Yang;Zhou, Ji
    • Structural Engineering and Mechanics
    • /
    • v.66 no.5
    • /
    • pp.583-594
    • /
    • 2018
  • A theoretical formulation based on the linearized potential theory, the Descartes' rule and the extremum optimization method is presented to calculate the critical distance of lifting points of the fully balanced hoist vertical ship lift, and to study pitching stability of the ship lift. The overturning torque of the ship chamber is proposed based on the Housner theory. A seven-free-degree dynamic model of the ship lift based on the Lagrange equation of the second kind is then established, including the ship chamber, the wire rope, the gravity counterweights and the liquid in the ship chamber. Subsequently, an eigenvalue equation is obtained with the coefficient matrix of the dynamic equations, and a key coefficient is analyzed by innovative use of the minimum optimization method for a stability criterion. Also, an extensive influence of the structural parameters contains the gravity counterweight wire rope stiffness, synchronous shaft stiffness, lifting height and hoists radius on the critical distance of lifting points is numerically analyzed. With the Runge-Kutta method, the four primary dynamical responses of the ship lift are investigated to demonstrate the accuracy/reliability of the result from the theoretical formulation. It is revealed that the critical distance of lifting points decreases with increasing the synchronous shaft stiffness, while increases with rising the other three structural parameters. Moreover, the theoretical formulation is more applicable than the previous criterions to design the layout of the fully balanced hoist vertical ship lift for the ensuring of the stability.

Balanced Buck-Boost Switching Converter to Reduce Common-Mode Conducted Noise

  • Shoyama Masahito;Ohba Masashi;Ninomiya Tamotsu
    • Proceedings of the KIPE Conference
    • /
    • 2001.10a
    • /
    • pp.212-216
    • /
    • 2001
  • Because conventional switching converters have been usually using unbalanced circuit topologies, parasitic capacitance between the drain/collector of an active switch and the frame ground through its heat sink may generate the common-mode conducted noise. We have proposed a balanced switching converter circuit, which is an effective way to reduce the common-mode conducted noise. As an example, a boost converter version of the balanced switching converter was presented and the mechanism of the common-mode noise reduction was explained using equivalent circuits. This paper extends the concept of the balanced switching converter circuit and presents a buck-boost converter version of the balanced switching converter. The feature of common-mode noise reduction is confirmed by experimental results and the mechanism of the common-mode noise reduction is explained using equivalent circuits.

  • PDF

High Effciency Balanced Power Amplifier (고효율 평형 전력 증폭기)

  • 신헌철;김갑기;이창식;이종악
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.8 no.4
    • /
    • pp.323-331
    • /
    • 1997
  • In this paper, the high efficiency balanced amplifier is presented as high efficiency power amplifier. This amplifier is basically composed of two FETs, an input power divider, output power combiner, input matching circuits, output matching circuits, second harmonic interconnection circuit and lowpass filter. The second harmonic interconnection circuit is composed of second harmonic frequency bandpass filter and transmission line. This circuit is inserted between the output terminals of the two FEF's output matching circuit, there is a second harmonic standing wave generated between two FET outputs. The electric wall termination is equivalent to the short circuit termination. As a result, the FET output termination condition needed to attain high efficiency is realized. Experimental high efficiency balanced amplifier is constructed to determine its practically attainable efficiency. The input VSWR is 1.27, and the output VSWR is 1.18. Power added efficiency of 75% is attained at 1.75 GHz band about 3W to balanced amplifier.

  • PDF

Neutral Line Current Analysis of Three-phase Four-wire Power System (3상 4선식 전력 시스템의 중성선 전류 분석)

  • Min Joon-Ki;Kim Hyng-Chul;Kim Su-Chel;Choi Jae-Ho
    • Proceedings of the KIPE Conference
    • /
    • 2006.06a
    • /
    • pp.492-494
    • /
    • 2006
  • Neutral line current is analyzed by the neutral line CF in nonlinear load balanced and unbalanced conditions. The worst nonlinear load condition is nonlinear balanced load condition, and It is below CFNL=1.194 that a neutral line current could not excess the rated value

  • PDF

Study on the Size of Minimal Standardized Detectable Difference in Balanced Design of Experiments (실험계획법에서 최소 표준화 검출 가능 효과의 크기에 관한 연구)

  • 임용빈
    • Journal of Korean Society for Quality Management
    • /
    • v.26 no.4
    • /
    • pp.239-249
    • /
    • 1998
  • In balanced design of experiment sample size is determined to detect a certain standardized size of effect with power 1-$\beta$ at the level of significance $\alpha$. Tables (Marvin, et al (1970) and Lorenzen and Anderson(1993) and charts (Odeh and Fox(1991)) are available to determine the sample size in balanced design of experiments. To simplify those tables and charts simple MATLAB program is used to find the minimal standardized detectable difference $\delta$ when $\alpha , \beta$ and sample size are given.

  • PDF

Fabrication of Balanced CPM(Colliding Pulse Mode-locked) Ring Dye Laser (Balanced CPM(Colliding Pulse Mode-locked) 링 색소 레이저 제작)

  • 정영붕;김동호;이인원
    • Korean Journal of Optics and Photonics
    • /
    • v.1 no.2
    • /
    • pp.185-190
    • /
    • 1990
  • Balanced CPM ring dye laser was fabricated. Pulses as short as 62 fs were measured using noncollinear second harmonic generation autocorrelator. The optimum conditions were studied by changing the concentration of staturable absorber, pumping power of Ar+ laser and alignments of the intracavity four-prism sequence.

  • PDF

A Study on Balanced -type Oseillating Mole-Drainer(III)-Model Test for Draft Force, Torque, Power and Moment (평행식 진동탄환 암거 천공기의 연구(III)-견인력, 토크, 동력 및 모멘크에 관한 모형시험-)

  • 김용환
    • Journal of Biosystems Engineering
    • /
    • v.1 no.1
    • /
    • pp.1-6
    • /
    • 1976
  • This paper is the third one of the study on balanced type oscillating mole-drainer, the first one was presented in No 9. Gyeongsang College Report and the second one in Vol. 17, No.4 of the KSAE. In the first part of this study, the characteristics of traction forces between the nonoscillating earth working equipments and oscillating ones was compared. A model of the balanced type oscillating mole-drainer, which composed of a mechanism that may reduce the machine vibration, was designed following the dimensional analysis and similitude technique. The model test was carried out to clarify the balancing mechanism of the oscillating parts and other parts of the machine. In the light of the results from the model tests, a prototype machine was made for experimental purpose. Results from the field test by a reported in the near future. In the second report, the model tests were carried out under the same soil conditions, i.e, . oscillating frequency, running velocity, and oscillating amplitude, etc. It was clear that use of balanced type oscillating model could substantially reduce the vibration of the whole system of the machine, when compared with the nonoscillating type model. In this paper(the third report), results of investigation on the traction force, power requirement, and moment. etc, is presented. Analysis of variance technique was used for analyzing the effect of the frequency, amplitude, and running velocity on the draft force, torque, power requirements, and moments. The results obtained from the model tests are as follows, 1) By practicing a balanced-type oscillating mole-drainer, it was possible to reduce the traction resistance by 55.1-61. 2 percent of traction resistance, however, was 1.75 - 1.95 times greater than the value of resistance which was induced by use of a mole-drainer with single bullet. The resistance of rear shank against soil was considered as a main causing factor of the above results. 2) As the oscillation frequency was increased, the traction resistance was decreased. Considering on the effect of oscillation the greater the amplitude, and the slower the running velocity was, the greater the reduction ratio of traction resistance was. 3) The ratio of the traction resistance of oscillating mole-drainer to that of non-oscillating one could be represented as a function of dimensionless variable (V/$Af$). The results from the tests were well agreed with the reported results from the experim ents on oscillation plow or hoe. 4) By taking a lower value of (V/$Af$), reducing the traction resistance was possible. This fact meant, however, that the efficiency of mole drain practice would be lower. 5) It was experimentally confirmed under the same condition of soil that the variable (R/$rD1^3$) could be represented as a function of a variable($V^2/gD$) when a non\ulcornerocillating mole-drainer was used. 6) When a oscillating mole-drainer was used, the variable(R/$rD_1^{3}$) could be represented as a function of two variables ($v^2/gD_1$) and (V^2/gD_1$). 7) The torque was not affected by a change of frequency. However, a relation of proportionality existed between torque and amplitude, running velocity, and ratio of bullet diameter. When a balanced type oscillating mole-drainer with two bullets was used, torque was increased by 52.8-78. 4 percent and total power requirement was also increased. 8) Total power requirement was increased linearly in accordance with the increasing frequency, 41.96 percent of total power was used for oscillating action. The magnitude of total power requirement was 1. 8-9. 4 times greater than that of a non-oscillating mechanism. In the view point of power requirement, it was not advisable to increase the frequency, amplitude, running velocity, and ratio of bullet diameter at the same time. 9) Only the positive moment occured in the rear shank. Change of the diameter of a rear bullet, could not affect the balancing against the soil resistance. It was necessary for rear bullet to have a large resistance against soil only when the rear bullet was in backward motion. 10) Within an extent of the experimental base, optimum limits for several design factors were A=0.5cm, $f$=22.5Hz, V=O. 05m/sec, and $\lambda$=1.0 By adapting these values traction resistance was reduced by 40 percent and vibration acceleration wa s reduced by 60 percent. Even though the total , power requirements for operating a balanced type oscillation mechanism was greater ~than that of non-oscillating one, using a oscillating mechanism would be more effective. Because a balanced type oscillating mechanism is used, tractive resistance will be reduced and then the lighter . tractive equipment could be used.

  • PDF