• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.14 no.4
• /
• pp.39-47
• /
• 2000

This paper presents the sinusoidal tracking controller in error to eliminate the steady state control error and to improve the transient characteristics for input current in voltage source PWM converter with input current estimation. The estimation method of input current values and configuration of controller are described. DC output voltage is controlled by PI controller, and sinusoidal tracking current controller which tracks directly AC input current is used as input current controller. The sinusoidal tracking current controller can be used without any coordinate transformation algorithms.It is proved that the steady state deviation of input current reduces to zero and the proposed control system is not affected by input voltage from transfer functions of input current control system. The validity of proposed scheme is verified by simulations and experimental results for load resister and input voltage variation.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2011.02a
• /
• pp.236-236
• /
• 2011

본 연구 축전 결합형 고주파 플라즈마(CCP) 식각장비에 펄스 직류(Pulse DC) 전원을 인가하여 오실로스코프(oscilloscope)를 분석하여 전기적 특성을 평가하는 것이다. 펄스 직류전원 플라즈마 시스템에서는 다양한 변수를 이해하여야 한다. 본 실험에서 사용한 공정 변수는 Pulsed DC Voltage 300~500 V, Pulsed DC reverse time $0.5{\sim}2.0{\mu}s$, Pulsed DC Frequency 100~250 kHz 이었다. 실험 결과를 정리하면 1) Pulsed DC Voltage 가 증가할수록 Input voltage의 최대값은 336~520 V, 최소값은 -544~-920 V로 변하여 피크 투 피크 (peak to peak)값은 880~1460 V로 증가였다. Input current 또한 최대값은 1.88~2.88 A, 최소값은 -0.84~-1.28 A로 변하여 피크 투피크 값은 2.88~4.24 A로 증가하였다. 이는 척에 인가되는 전류와 파워의 증가를 의미한다. 2) Pulsed DC reverse time이 증가하면 Input voltage와 Input current값이 증가했다 (Input voltage의 피크 투 피크 값은 1200~1440 V, Input current의 피크 투 피크 값은 3.56~4.56 A). 3) Pulsed DC frequency가 증가하면 주기가 짧아져 Input voltage와 Input current값이 증가 한다 (Input voltage의 피크 투 피크 값은 900~1320 V, Input current의 피크 투 피크 값은 2.36~3.64 A). 결론적으로 펄스 직류 플라즈마의 다양한 전기적 변수들은 반응기 내부에 인가되는 Input voltage와 Input current의 값에 큰 영향을 준다는 것을 알 수 있었다.

• Proceedings of the KIPE Conference
• /
• 2017.07a
• /
• pp.178-179
• /
• 2017

Input filter is an essential component in a practical matrix converter (MC) system to generate the sinusoidal input currents. However, the input filter causes a displacement angle between the input current of MC and the source current. In this paper, we investigate the input filter design for MCs by considering the displacement angles of the input current and the input voltage to guarantee high input power factor (IPF) operation as well as low input current harmonic contents. Simulation results are provided to validate the input filter design with near unity input power factor and low total harmonic distortion (THD) of the input current.

• Proceedings of the KIEE Conference
• /
• 1996.07a
• /
• pp.376-378
• /
• 1996

This paper presents a new PFC control method which replaces a fast line current measurement with a filtered load current measurement. Using the power balance relation between the input and the output of the boost converter. the input current can be described as the function of load current. Thus the PWM signal which effects the switching control of the boost converter is generated using the PFC input voltage, the PFC output voltage and the load current as input variables. By using a filter between the bridge rectifier and a dc-to-dc converter, the input voltage of the dc-to-dc converter is forced to always maintain above zero volt. Then the input current traces a sinewave in phase. The proposed scheme accomplishes a very high power factor and a low harmonic distortion of the line current. The validity of this scheme is demonstrated through simulation.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.19 no.3
• /
• pp.220-226
• /
• 2014

Input current ripple and harmonic components of the power device are main causes of electromagnetic interference (EMI). Although the discontinuous conduction mode (DCM) operation can reduce harmonic components of the power device by reducing reverse recovery current of diode and turn-off voltage spikes of the switch, input current ripple increases due to high peak to peak inductor current. Therefore, in this paper, frequency control algorithm is proposed to reduce the input current ripple of DCM operated interleaved boost converter. In the proposed algorithm, duty ratio is fixed either 0.33 or 0.67 to minimize the input current ripple and the switching frequency is controlled according to operating conditions. 600 W 3-phase interleaved boost converter prototype system is built to verify proposed algorithm.

• Journal of the Korean Institute of Telematics and Electronics C
• /
• v.34C no.10
• /
• pp.19-26
• /
• 1997

Novel class AB CMOS second-generation current conveyors (CCII) using 0.6.mu.m n-well CMOS process for high-frequency current-mode signal processing were developed. The CCII for low power operation consists of a class AB push-pull stage for the current input, a complementary source follower for the voltage input, and a cascode current mirror for the current output. In this architecture, the two input stages are coupled by current mirrors to reduce the current input impedance. Measurements of the fabricated CCII show that the current input impedance is 875.ohm. and the bandwidth of flat gain when used as a voltage amplifier extends beyond 4MHz. The power dissipation is 1.25mW and the active chip area is 0.2*0.15[mm$\^$2/].

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.38 no.10
• /
• pp.754-764
• /
• 2001

Class A bipolar second-generation current conveyor (CCII) with low current-input impedance and its offset-compensated CCII for high-accuracy current-mode signal processing are proposed. The CCIIs consist of a regulated current-cell for current input, a emitter follower for voltage input, and a cascode current mirror lot current output. In these architecture, the two input stages are coupled by current mirror to reduce the current input impedance. Experiments show that the CCII has impedance of 8.4 Ω and offset voltage of 40 mV at current input terminal. To reduce this offset, the offset-compensated CCII adopts diode-connected npn and pnp transistor in the proposed CCII. Experiments show that the offset-compensated CCII has current input impedance of 2.1 Ω and offset voltage of 0.05 mV. The 3-dB cutoff frequency of the CCIIs when used as a voltage follower extends beyond 30 MHz. The power dissipation is 7.0 mW

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.62 no.6
• /
• pp.767-781
• /
• 2013

In this paper, we proposes the AC input voltage and current sensorless control scheme to control the input power factor and DC output voltage of the three-phase Z-source PWM rectifier. For DC-link voltage control which is sensitive to the system parameters of the PWM rectifier, fuzzy-PI controller is used. Because the AC input voltage and current are estimated using only the DC-link voltage and current, AC input voltage and current sensors are not required. In addition, the unity input power factor and DC output voltage can be controlled. The phase-angle of the detected AC input voltage and estimated voltage, the response characteristics of the DC output voltage according to the DC voltage references, the FFT results of the estimated voltage and current, efficiency, and the response characteristics of the conventional PI controller and fuzzy-PI controller are verified by PSIM simulation.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.25 no.2
• /
• pp.152-155
• /
• 2020

This study proposes an input filter for a gallium-nitride-based direct matrix converter with a stepless current commutation technique. Various current commutation strategies have been adopted for reliable operation of switches. These strategies are complex to be implemented and require additional components. The stepless current commutation technique is simple to operate but causes overcurrent issues due to the occurrence of short circuit on input sources. In this study, to restrict the short circuit current, we utilized GaN devices with fast switching properties and modified the input filter. The proposed input filter was verified by experimental results of induction motor drive.

• Proceedings of the KIPE Conference
• /
• 1997.07a
• /
• pp.345-351
• /
• 1997

In this paper, controller for PWM converter considering unsymetrical input voltage is designed and current controller using LQ controller with conditional integrator is proposed. And the proposed current controller is compared with other current controller-predictive controller, decoupling PI controller. As simulation results, LQ controller with Conditional Integrator shows the improved performance for DC link voltage regulation through transient test of load variation. And when unsymeritrical input voltage is applied to converter with conventional current controller considering only symetrical input voltage, input current is distorted but it is showed that current controller considering unsymetrical input has robust control characteristics under phase voltage unbalance.