• 전력전자학회논문지
• /
• 제25권1호
• /
• pp.54-60
• /
• 2020

A digital current control scheme using virtual d-q transformation for a boost single-phase power factor correction (PFC) converter is proposed. The use of virtual d-q transformation in single-phase power converters is known to improve current control performance. However, the conventional virtual d-q transformation-based digital current control scheme cannot be directly applied to the boost single-phase PFC converter because the current and average voltage waveforms of the inductor used in the converter are not sinusoidal. To cope with this problem, this study proposes a virtual sinusoidal signal generation method that converts the current and average voltage waveform of the inductor into a sinusoidal waveform synchronized with the grid. Simulation and experimental results are provided to show that the virtual d-q transformation-based digital current control is successfully applied to the boost single-phase PFC converter with the aid of the proposed virtual sinusoidal signal generation method.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 A
• /
• pp.87-90
• /
• 2003

There are generally two temperature control methods using ac voltage regulators - the phase control method and the on-off control method. The phase control method uses thyristor's angles of extinction for the output power regulation and the on-off control method uses the control of on and off times for the output power regulation. Both of methods have the problems that are the unbalance of the three phase and surge current caused system's destruction. The main object of this study proposes a solution of problems of surge currents and unbalance of three phase when thyristor voltage regulator is switching. To solve the problem, It is proposes that the solution of surge currents is using a tap transformer and an additional switch with adjustable resistance and applies zero crossing of switching voltage of two input line to power load. This method is discuss and verified by computer simulations and experiments.

• Journal of Power Electronics
• /
• 제11권6호
• /
• pp.824-836
• /
• 2011

A new fault-tolerant control topology for open-loop motor-drive systems with Delta-connected stator windings is introduced in this paper. This new control topology enables the operation of a three-phase induction machine as a two-phase machine fed by a three-phase inverter upon a failure in one of the motor phases. This topology utilizes the "open-Delta" configuration to independently control the current in each of the two remaining healthy phases. This new control technique leads to the alleviation of any torque pulsations resulting from the consequences of the asymmetrical conditions associated with this class of faults.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2000년도 하계학술대회 논문집 B
• /
• pp.644-646
• /
• 2000

An induction motor can be controlled like a separately excited do motor by field oriented control(or vector control). In vector control, Because the transformation of the stator's 3-phase current into two orthogonal current is required. the control scheme is complicated. But, Yamamura proposed a field acceleration method(FAM) without the phase transformation. FAM simplify an implementation control scheme for induction motors. In this paper, the analysis of transient phenomena of a squirrel-cage induction motor was achieved by the spiral vector method and the phase segregation method. It simplified control schemes more than those of vector control.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
• /
• 제55권1호
• /
• pp.27-32
• /
• 2006

In this paper, a new scheme of current programmed control for three phase PWM AC-AC converter is presented. Compared to duty-ratio voltage control, current programmed control has several advantages such as reduction of system order, inherent current protection and robust output. By considering only the magnitude components, a similar scheme in the DC-DC converter can be extended to the three phase PWM AC-AC converter. The proposed current programmed control will be well adopted into various converter topologies though three phase PWM AC-AC boost converter is treated as an example. The converter analysis is carried out by applying the vector DQ transformation to obtain physical insight into the converter operation and to establish some important characteristic equations for control purpose. The experiment results show the validity of the proposed scheme.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2002년도 추계학술대회 논문집
• /
• pp.199-202
• /
• 2002

This paper suggests the control algorithm of a 3-phase 3-wire series active power filters which have harmonic voltage source and harmonic current source This suggested control algorithm can compensate harmonics which are generated by nonlinear load such as diode or thyristor converter and reactive power in 3-phase 3-wire power distribution system This control algorithm extracts a compensation voltage reference from performance function without phase transformation Therefore this control algorithm is simpler than any other conventional control algorithm. 3-phase 3-wire series active power filter and hybrid active power filter is manufactured and experiments are carried out for harmonic voltage source and harmonic current source to verify the effectiveness of presented control algorithm Experimental results are presented in this Paper, as well.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1987년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 16-17 Oct. 1987
• /
• pp.312-316
• /
• 1987

A simple hybrid circuit to control the two-phase AC motor of the nut-runners which employ the tightening torque control system is described in this paper. The circuit has emphasis on the low-cost implementation. The circuit constitutes of the V/F converter using a timer IC, the pulse width modulator using the fastening torque signal and the two-phase logic sequencer.

• 한국전자통신학회논문지
• /
• 제16권1호
• /
• pp.45-52
• /
• 2021

3상 PWM 정류기에 대한 공간벡터제어 기반 전압제어방식은 스위칭 구간에 대한 스위칭 패턴을 설계해야하기 때문에 최적한 스위칭 패턴을 설계하는데 많은 노력이 요구된다. 본 연구에서는 3상 6펄스 전압형 PWM 정류기를 위한 D-Q 제어에 기반 한 SPWM 출력전압 제어 알고리즘을 연구하였다. 출력전압제어 알고리즘에서 3상 기준신호들은 공간벡터 표시법에 기반 한 D-Q 변환으로부터 얻어지며 스위칭 패턴 대신에 SPWM 방식을 이용하여 정류기 스위칭 제어 신호들을 생성하도록 하였다. 다음으로, EMTP-RV를 이용하여 D-Q 제어기반 SPWM 방식을 가지는 3상 6펄스 전압형 PWM 정류기를 모델링하였다. 끝으로, EMTP-RV 시뮬레이션을 통해 얻어지는 출력전압파형을 기준 값과 비교, 출력전압이 기준전압을 정확하게 추종함을 확인함으로서 D-Q 제어기반 SPWM 전압제어 알고리즘의 유효성을 확인할 수 있었다.

• 제어로봇시스템학회논문지
• /
• 제10권4호
• /
• 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.

• Journal of Power Electronics
• /
• 제13권3호
• /
• pp.487-496
• /
• 2013

The three-phase synchronous reference frame phase-locked loop (SRF-PLL) is widely used for synchronization applications in power systems. In this paper, a new control strategy for three-phase grid-connected LCL inverters without a PLL is presented. According to the new strategy, a current reference can be generated by using the instantaneous power control scheme and the proposed positive-sequence voltage detector. Through theoretical analysis, it is indicated that a high-quality grid current can be produced by introducing the new control strategy. In addition, a kind of independent control for reactive power can be achieved under unbalanced and distorted grid conditions. Finally, the excellent performance of the proposed control strategy is validated by means of simulation and experimental results.