• Journal of international Conference on Electrical Machines and Systems
• /
• 제3권2호
• /
• pp.155-161
• /
• 2014

Industrial Static Var Generator (SVG) is typically applied at or near the load center to mitigate voltage fluctuation, flicker, phase unbalance, non-sine distortion or other load-related disturbance. Special attention is paid to the influence of grid voltage quality on SVG current, the non-sine distortion and unbalance of grid voltage causes not only the AC current distortion and unbalance but also the DC voltage fluctuation. In order to let the inverter voltage contain the fundamental negative sequence and harmonic component corresponding to the grid voltage, a new dual-loop control scheme is proposed to suppress the influence in this paper. The harmonic and negative sequence voltage decomposition algorithm and DC voltage control are also introduced. All these analyses can guide the practical applications. The simulation results verify the feasibility and effectiveness of the present control strategy and analyses.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1991년도 추계학술대회 논문집 학회본부
• /
• pp.160-163
• /
• 1991

Permanent Magnet Synchronous Motor(PMSM) has merits in both simple electrical controllability of dc motor and mechanical reliability of ac motor by applying vector control. The vector control method orients the armature current phasor to be perpendicular to the permenant magnet rotor flux in a two-axis coordinate frame, and provides control characteristics that are similar to those of separately excited dc motors. This paper presents a simple model following scheme for position control of PMSM fed by hysteresis current-controlled PWM inverter. The simulation results show the validity of the proposed control method.

• Journal of Electrical Engineering and Technology
• /
• 제8권6호
• /
• pp.1352-1364
• /
• 2013

This paper describes a novel structure for single phase Unified Power Quality Conditioner-Distributed Generation (UPQC-DG) with direct grid connected DC-AC converter for low DC output DG systems which can be used not only for compensation of power quality problems but also for supplying of load power partly. This converter has been composed of one full-bridge inverter, one three winding high frequency transformer with galvanic isolation and two cycloconverters. Proper control based on Input Output feedback Linearization is used to tracking the reference signals. The simulation and experimental results are presented to confirm the validity of the proposed approach.

• 대한전기학회논문지:전력기술부문A
• /
• 제49권6호
• /
• pp.272-279
• /
• 2000

This paper describes a controller design and dynamic performance analysis of UPFC based on 3-level inverters. Major attention is focused on the controller design for both shunt and series inverters, including regulator design for the dc link voltage sharing across the dc capacitors. An energy-based approach was investigated for effectively designing the controller. A detailed UPFC model has been developed with EMTP using 24-pulse 3-level inverters to verify this approach. Simulation results about dynamic performance of UPFC confirm effects for increasing transmission capacity and damping low-frequency oscillation. The developed simulation model would be very effective to analyze the dynamic performance of UPFC.

• Journal of Biosystems Engineering
• /
• 제17권4호
• /
• pp.326-335
• /
• 1992

This study was carried out to develop a measurement and analysis system of ride vibrations of tractors. The system consists of a portable digital computer, a PCL-812 PG interface card for A/D conversion, two accelerometers, two signal conditioners, a DC-AC power inverter and a DC power supplier. The computer programs installed in the system for data acquisition and analysis were also developed. It was intended that the system should be cheap enough to be afforded by college laboratories but reliable in its functions of measurement and analysis. Characteristics of the components and methods used in the system development were discussed.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2001년도 전력전자학술대회 논문집
• /
• pp.552-555
• /
• 2001

This paper deal with the power factor improvement of DC power regenerating systems, which are composed of two inverters, zig-zag connected output transformers, and an AC filter. The output voltages of the inverter system are not sinusoidal. Regenerated complex power is analyzed on the basis of fundamental components and therefore the reactive power produced by harmonics is not considered. Therefore, it is needed a new control scheme capable of controlling the reactive power nearly to zero for nonsinusoidal case. Computer simulations are carried out to verify the validity of the proposed control scheme.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1992년도 하계학술대회 논문집 B
• /
• pp.1211-1214
• /
• 1992

본 논문에서 제안한 Fara DS Series의 AC SERVO (DC BRUSHLESS) MOTOR 제어기는 ROBOT, CNC, 각종 공작기계및 FA기기에서 MOTOR를 구동 원으로 사용하는데 사용되는 제품이다. AC SERVO MOTOR DRIVE의 Inverter에 IGBT(Insulated Gate Bipoler Transistor)를 사용하여 Switching 주파수를 높임으로써 Motor를 가변속 제어할때 발생하는 소음 및 진동을 극소화 하였다. 또한 일반적으로 Motor 속도제어를 급감속으로 제어할때 Servo Motor의 비선형 특성으로 인한 전류위상을 보상하여 모든 동작구간에서 최적의 상태의 제어가 되도록 개발하였다. 그리고 다양한 User Option 기능을 내장하여 User가 원하는 제어대상에 효과적으로 적용할 수 있도록 하였다. 아울러 MOTOR 제어기에 내장 된 다수의 보호기능을 통해서 Motor운전중 발생하는 이상상태에 대해 제어기를 보호할 수 있도록 하였다. 제안한 제어기는 부하변동, 전압변동, 온습도변동에 대해 속도변동율을 최소화 함으로써 ROBOT, CNC등 FA분야에서 폭넓게 이용할수 있다.

• 조명전기설비학회논문지
• /
• 제23권8호
• /
• pp.48-56
• /
• 2009

본 논문은 연료전지스택을 입력전원으로 하는 TIG-용접기용 전력변환장치를 제안하였다. 일반적으로 TIG-용접기의 전원공급장치는 상용전원을 이용한 다이오드 브리지 정류회로를 사용한다. 이런 회로의 경우 다이오드 정류기와 용량이 큰 캐패시터를 사용하게 되므로 부피가 커지고, 입력전류는 맥동성분과 고조파를 포함하게 된다. 또한, TIG-용접기는 상용전원의 사용이 여의치 않은 도서산간지역이나 특수한 환경에서는 소형 경량의 이동성이 수월한 전원장치 및 전력원을 필요로 하게 된다. 따라서 본 논문의 TIG-용접기용 전력변환장치는 고체고분자형연료전지(PEMFC)를 입력전원으로 사용하고, 부스트 컨버터의 기능과 인버터 용접전원의 기능을 하나의 풀-브리지 컨버터로 구성하였다. 제안한 연료전지를 이용한 TIG-용접기용 전력변환장치는 컴퓨터 시뮬레이션과 실험을 통하여 성능을 검증하였다.

• 전기학회논문지
• /
• 제57권10호
• /
• pp.1796-1801
• /
• 2008

In this paper, a new current based maximum power point tracking (CMPPT) method is proposed for a single phase photovoltaic power conditioning system and the current based MPPT modifies incremental conductance method. The current based MPPT method makes the entire control structure of the power conditioning system simple and uses an inherent current source characteristic of solar cell array. In addition, digital phase locked loop using an all pass filter is introduced to detect phase of grid voltage as well as peak voltage. Controllers about dc/dc boost converter, dc-link voltage, dc/ac inverter is designed for a coordinated operation. Furthermore, PI current control using a pseudo synchronous d-q transformation is employed for grid current control with unity power factor. 3kW prototype photovoltaic power conditioning system is built and its experimental results are given to verify the effectiveness of the proposed control schemes.

• Journal of Power Electronics
• /
• 제16권1호
• /
• pp.190-204
• /
• 2016

An active front end (AFE) is required for a three-phase induction motor (IM) fed by a voltage source inverter (VSI), because of the increasing need to derive quality current from the utility end without sacrificing the power factor (PF). This study investigates a proportional-plus-integral (PI) controller based AFE topology that uses a super-lift converter (SLC). The significance of the proposed SLC, which converts rectified AC supply to geometrically proceed ripple-free DC supply, is explained. Variations in several power quality parameters in the intended IM drive for 0% and 100% loading conditions are demonstrated. A simulation is conducted by using MATLAB/Simulink software, and a prototype is built with a field programmable gate array (FPGA) Spartan-6 processor. Simulation results are correlated with the experimental results obtained from a 0.5 HP IM drive prototype with speed feedback and a voltage/frequency (V/f) control strategy. The proposed AFE topology using SLC is suitable for three-phase IM drives, considering the supply end PF, the DC-link voltage and current, the total harmonic distortion (THD) in supply current, and the speed response of IM.