• Title, Summary, Keyword: Voltage phase

Search Result 4,141, Processing Time 0.048 seconds

Sensorless Control of Three Phase Converter using estimated Input Phase-Voltage and DC-link Voltage (전원전압과 DC-link 전압 추정을 통한 3상 컨버터 센서리스 제어)

  • Chu, Hung-Seok;Park, Sung-Jun;Kim, Kwong-Tae;Kim, Cheul-U
    • Proceedings of the KIEE Conference
    • /
    • /
    • pp.1233-1235
    • /
    • 2000
  • A new control method of three phase converter without measuring input phase-voltage and DC-link voltage is proposed. Input phase-voltage of these required voltages is estimated using EKF(Extended Kalman Filter) and DC-link voltage is estimated from the measured line currents and the estimated input phase-voltage. This control method is achieved without PLL(Phase Locked Loop) which senses the angle of input phase-voltage and DC-link voltage sensor. In addition, the proposed method controls high power factor and DC-link voltage utilizing the estimated phase angle. This paper describes the effectiveness of the proposed estimated algorithm through simulations.

  • PDF

Sensorless Control of Three Phase Converter using estimated Input Phase-Voltage and DC-link Voltage (전원전압과 DC-link 전압 추정에 의한 3상 컨버터 센서리스 제어)

  • Chu Hung-Seok;Cheon Chang-Gun;Ahn Jin-Woo;Kim Cheul-U
    • Proceedings of the KIPE Conference
    • /
    • /
    • pp.227-230
    • /
    • 2001
  • A new control method of three phase converter without measuring input Phase-voltage and DC-link voltage is Proposed. Input Phase-voltage of these required voltages is estimated using EKF(Extended Kalman Filter) and DC-link voltage is estimated from the measured line currents and the estimated input phase-voltage. This control method is achieved without PLL(Phase Locked Loop) which senses the angle of input phase-voltage and DC-link voltage sensor. In additon, the proposed method controls high power factor and DC-link voltage utilizing the estimated phase angle. This paper describes the effectiveness of the proposed estimated algorithm through simulations.

  • PDF

Single-Phase Z-Source AC/AC Converter with Wide Range Output Voltage Operation

  • Nguyen, Minh-Khai;Jung, Young-Gook;Lim, Young-Cheol
    • Journal of Power Electronics
    • /
    • v.9 no.5
    • /
    • pp.736-747
    • /
    • 2009
  • A new type of single-phase Z-source AC/AC converter based on a single-phase matrix converter is proposed in this paper. The proposed single-phase Z-source AC/AC converter has unique features; namely that the output voltage can be bucked and in-phase/out-of-phase with the input voltage; that the output voltage can be boosted and in-phase/out-of-phase with the input voltage. The converter employs a safe-commutation strategy to conduct along a continuous current path, which results in the elimination of voltage spikes on switches without the need for a snubber circuit. The operating principles of the proposed single-phase Z-source AC/AC converter are described, and a circuit analysis is provided. To verify the performance of the proposed converter, a laboratory prototype based on a TMS320F2812 DSP was constructed. The simulation and the experimental results verified that the output voltage can be bucked-boosted and in-phase with the input voltage, and that the output voltage can be bucked-boosted and out-of-phase with the input voltage.

A Study on the Reliability of DVR in a 3-Phase Phase-Controlled Rectifier

  • Kim, Woo-Hyun;Park, Chul-Woo
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.26 no.11
    • /
    • pp.54-61
    • /
    • 2012
  • This study investigated the relationship between the response time of DVR (Dynamic Voltage Restorer) and the possible compensation range for voltage dips by the DVR system which protects the 3-phase phase-controlled rectifier from said dips. As a result, the permissible range of voltage dip is presented in a 3-phase phase-controlled rectifier. When the DVR compensates for voltage dip, the range of voltage dip can be compensated according to the DVR's response time. Using the proposed method, DVR response time can be determined from the parameters of the 3-phase phase-controlled rectifier and the possible compensatory range of voltage dip, while at the same time it is possible to use a control system having an appropriate speed. Therefore, the use of excessively fast equipment can be avoided, improving the stability of the overall system. The reliability of the DVR concerning the 3-phase phase-controlled rectifier can be verified by simulation.

Comparative Analysis of Voltage Unbalance Factor on the use of Linear and Non-linear loads in Three-phase Four-wire Low Voltage Distribution Line (3상 4선식 저압 배전선로에서 선형 및 비선형 부하의 사용시 전압 불평형률 비교 분석)

  • Kim, Jong-Gyeum;Kim, Ji-Myeong
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.66 no.3
    • /
    • pp.587-592
    • /
    • 2017
  • In the three-phase four-wire low-voltage power distribution equipment, single-phase and three-phase load have been used mainly mixed. Also linear and nonlinear loads have been used together in the same conditions. In a three-phase four-wire distribution line, the current distribution of three-phase linear load is almost constant in each phase during driving or stopping, but the single-phase load is different from each other for each phase in accordance with the operation and stop. So that the voltage unbalance is caused by the current difference of each phase. In the three-phase four-wire distribution system, non-linear load is used with linear load. The presence of single-phase nonlinear loads can produce an increase in harmonic currents in three-phase and neutral line. It can also cause voltage unbalance. In the present study, we analyzed for the voltage unbalance fluctuations by the operation pattern of the single and three-phase linear and non-linear load in three-phase four-wire low voltage distribution system.

Comparison of Voltage Unbalance Factor for Line and Phase Voltage (선간전압과 상전압에 대한 전압불평형율의 비교)

  • Kim Jong-Gyeum;Park Young-Jeen;Lee Eun-Woong
    • The Transactions of the Korean Institute of Electrical Engineers B
    • /
    • v.54 no.9
    • /
    • pp.403-407
    • /
    • 2005
  • Most of the loads in industrial power distribution systems are balanced and connected to three power systems. However, voltage unbalance is generated at the user's 3-phase 4-wire distribution systems with single & three phase. Voltage unbalance is mainly affected by load system rather than power system. Unbalanced voltage will draws a highly unbalanced current and results in the temperature rise and the low output characteristics at the machine. It is necessary to analyse correct voltage unbalance factor for reduction of side effects in the industrial sites. Voltage unbalance is usually defined by the maximum percent deviation of voltages from their average value, by the method of symmetric components or by the expression in a more user-friendly form which requires only the three line voltage readings. If the neutral point is moved by the unbalanced load at the 3-phase 4-wire system. Line and phase voltage unbalance leads to different results due to zero-sequence component. So that it is difficult to analyse voltage unbalance factor by the conventional analytical method, This paper presents a new analytical method for phase and line voltage unbalance factor in 4-wire systems. Two methods indicate exact results.

A study on the permissible range of voltage dips and the response time of DVR in 3-phase phase-controlled rectifier (3상 위상제어 정류기에서 DVR의 응답시간과 허용 가능한 순시저전압의 범위에 대한 연구)

  • 한무호;권우현;박철우
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.10 no.4
    • /
    • pp.325-333
    • /
    • 2004
  • It is investigated that the relation between the response time of DVR(Dynamic Voltage Restorer) and the possible compensation range of voltage dip by the DVR system which protects the 3-phase phase-controlled rectifier from voltage dip. As a result, the permissible range of voltage dip is presented in the 3-phase phase-controlled rectifier, and it is presented that the range of voltage dip which can be compensated according to the DVR s response time. when the DVR compensates voltage dip, Using the proposed method, the DVR s response time can be determined from the parameters of 3-phase phase-controlled rectifier and the possible compensation range of voltage dip, and it is possible to use the control system which have an appropriate speed. Therefore, the use of excessively fast device can be avoided, and the stability of the overall system is improved. Also the reliance of DVR about the 3-phase phase-controlled rectifier can be verified.

Connected Characteristics for Small Generation Source of Low Voltage Model Grids (저압 모의선로에 소형발전원 연계시 특성)

  • Lee, Sang-Woo;Kang, Jin-Kyu;Lee, Dong-Ha;Park, Tae-Joon
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.27 no.2
    • /
    • pp.45-53
    • /
    • 2013
  • In this paper, we analyze the typical phase voltage and line current waveform characteristics of the distribution system with 3 phase small synchronous generation source in case with load and non-load group, in order to investigate the power quality for end load connected of generation source. As demonstrated by our experimental results, the distortion and power quality of phase voltage and line current waveform were relatively good for low voltage 3 phase model grids connected of 3 phase small synchronous generation source in case with non-load group. However, distortion and power quality of voltage and current waveform was poor for low voltage 3 phase model grids connected to 3 phase small synchronous generation source in the load group with some phase voltage and frequency difference. From the above results, we conclude that the phase voltage and frequency of 3 phase generation source must be identical to that of distribution system source to maximize the power quality. Also, special attention is required in case of having load group or non-load group to 3 phase generation source.

Fast Detection Algorithm for Voltage Sags and Swells Based on Delta Square Operation for a Single-Phase Inverter System

  • Lee, Woo-Cheol;Sung, Kook-Nam;Lee, Taeck-Kie
    • Journal of Electrical Engineering and Technology
    • /
    • v.11 no.1
    • /
    • pp.157-166
    • /
    • 2016
  • In this paper, a new sag and peak voltage detector is proposed for a single-phase inverter using delta square operation. The conventional sag detector is from a single-phase digital phase-locked loop (DPLL) that is based on d-q transformations using an all-pass filter (APF). The d-q transformation is typically used in the three-phase coordinate system. The APF generates a virtual q-axis voltage component with a 90° phase delay, but this virtual phase cannot reflect a sudden change in the grid voltage at the instant the voltage sag occurs. As a result, the peak value is drastically distorted, and it settles down slowly. A modified APF generates the virtual q-axis voltage component from the difference between the current and the previous values of the d-axis voltage component in the stationary reference frame. However, the modified APF cannot detect the voltage sag and peak value when the sag occurs around the zero crossing points such as 0° and 180°, because the difference voltage is not sufficient to detect the voltage sag. The proposed algorithm detects the sag voltage through all regions including the zero crossing voltage. Moreover, the exact voltage drop can be acquired by calculating the q-axis component that is proportional to the d-axis component. To verify the feasibility of the proposed system, the conventional and proposed methods are compared using simulations and experimental results.

Phase Shift Control for Series Active Voltage Quality Regulators

  • Xiao, Guochun;Teng, Guofei;Chen, Beihai;Zhang, Jixu
    • Journal of Power Electronics
    • /
    • v.12 no.4
    • /
    • pp.664-676
    • /
    • 2012
  • A phase shift algorithm based on the closed-loop control of dc-link voltage implemented on a series active voltage quality regulator (AVQR) is proposed in this paper. To avoid pumping-up the dc-link voltage, a general phase shift compensation strategy is applied. The relationships among the operation variables are discussed in detail, which is very important for guiding the design of both the main circuit and the control system. Then on the basis of an investigation of the dc-link voltage pumping-up from viewpoint of the active power flow, a novel phase shift control method based on the closed-loop of the dc-link voltage is proposed. This method can adjust the phase of the output voltage gradually and automatically according to the dc-link voltage variation without introducing a phase jump. The effectiveness of the proposed strategy is verified through simulations of a single-phase 5kVA prototype and laboratory experiments on both a single-phase 5kVA and a three-phase 15kVA prototype.