• 대한전기학회논문지:전력기술부문A
• /
• 제52권3호
• /
• pp.165-172
• /
• 2003

This paper presents an operation scheme to enhance the power system security by applying FACTS on Power systems. Three main generic types of FACTS devices are suggested an illustrated. Flow congestions over lines have been solved by controlling active power of series-compensated FACTS devices and low voltages at buses have been solved by controlling reactive power of shunt-compensated FACTS devices. Especially, Especially, UPFC has been applied in both line congestion and low voltages. Two kinds of indices which indicate the power system security level related to line flow and bus voltage are utilized in this paper. They have been minimized to enhance the power system security level through the iterative method and the sensitivity vector of security index is derived to determine the direction to minimum. The proposed algorithm has been tested on the IEEE 57-bus system with FACTS devices in a normal condition and a line-faulted contingency.

• 한국산학기술학회논문지
• /
• 제12권12호
• /
• pp.5838-5842
• /
• 2011

본 연구는 고용량의 모터를 구동하기 위한 모터컨트롤센터(MCC)의 내부 구조 중 각 상(R,S,T)의 BUS BAR의 온도와 BUS BAR 볼트 체결부의 온도변화가 모터컨트롤센터의 노후화 및 진동에 따라 어떠한 차이가 있는지를 적외선 온도센서가 설치된 온도측정용 2차원 기구부를 설계 제작하고 모터컨트롤센터의 내부에 설치하여 BUS BAR의 온도 및 전류 변화량을 상시 모니터링 하였다. 실험을 통하여 부하에 따른 BUS BAR의 온도 변화를 BUS BAR 나사 체결부위를 중심으로 측정하였으며, BUS BAR의 온도변화와 소모 전류에 대한 비례관계를 확인할 수 있었다. 또한 이러한 비접촉식 2차원 온도측정 시스템을 모터컨트롤센터 내부에 장착하면 부하의 과전류로 인한 온도 상승이나 접촉 불량 등으로 발생될 수 있는 정전이나 화재 사고를 예방할 수 있을 것으로 기대된다.

• 전기학회논문지
• /
• 제62권7호
• /
• pp.943-949
• /
• 2013

Recently, an electric vehicle (EV) has been become a huge issue in the automotive industry. The EV has many electrical units: electric motors, batteries, converters, etc. The DC distribution power system (DPS) is essential for the EV. The DC DPS offers many advantages. However, multiple loads in the DC DPS may affect the severe instability on the DC bus voltage. Therefore, a voltage bus conditioner (VBC) may use the DC DPS. The VBC is used to mitigate the voltage transient on the bus. Thus, a suitable control technique should be selected for the VBC. In this research, Current controller with fixed switching frequency is designed and applied for the VBC. The DC DPS consist of both a resistor load and a boost converter load. The load variations cause the instability of the DC DPS. This instability is mitigated by the VBC. The simulation results by Matlab simulink and experimental results are presented for validating the proposed VBC and designed control technique.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2013년도 추계학술대회 논문집
• /
• pp.243-244
• /
• 2013

This paper introduces the application of Profibus field bus communication in HVDC power system. Discusses about the configuration of HVDC system and the structure of control and protection system. Analyzes and designs the network configuration of field device level. Using OPAS engineering tool to config IO system and at the same time monitor data in SCADA HMI.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2000년도 하계학술대회 논문집 A
• /
• pp.227-229
• /
• 2000

This paper presents a LQG/LTR method for controlling the PSS and SVC effectively. A one-machine Infinite-bus power system is used as an analysis system, where PSS is installed at the synchronous generator and SVC at the generator bus as a parallel compensation device. The simulation results show that the LQG/LTR controller of PSS and SYC improves the power system stability effectively.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2019년도 전력전자학술대회
• /
• pp.467-468
• /
• 2019

This paper proposes an improved bus voltage regulation scheme in filter-based reference current generation of power management for DC home grid with photovoltaics (PV), battery, and ultracapacitor (ultracap) by using feedforward terms instead of the filter output to produce the ultracap reference current. Simulation results have proved the effectiveness of the proposed scheme.

• 전기학회논문지P
• /
• 제60권4호
• /
• pp.241-245
• /
• 2011

In this paper, when photovoltaic (PV) systems are connected to power distribution system, most effective capacity and connected-point of PV system are presented considering power distribution system reliability. The reliability model of PV system is presented considering the duration of sunshine. Also the model of time-varying load and reliability test system bus2 model are used. To simulate the effects of PV system, various cases are selected; (1) base case which is no connection of PV system to power distribution system when faults are occurred, (2) 3MW case which is 3[MW] connection of PV system (3) 4[MW] case, and (4) 20[MW] case which is 20[MW] connection of PV system to the bus of power distribution system. The capacity limit of connected PV system is settled to 14[MW] for all cases except case 4. The reliability for residential, general, industrial, and educational customer is evaluated.

• Journal of Electrical Engineering and Technology
• /
• 제10권4호
• /
• pp.1502-1507
• /
• 2015

This paper deals with shunt compensation to eliminate voltage violation and enhance transfer capability, which is motivated towards implementation in the Korean power system. The optimal shunt compensation algorithm has demonstrated its effectiveness in terms of voltage accuracy and reducing the number of actions of reactive power compensating devices. The main shunt compensation devices are capacitor and reactor. Effects of control devices are evaluated by cost computations. The control objective at present is to keep the voltage profile of a key bus within constraints with minimum switching cost. A robust control strategy is proposed to make the control feasible and optimal for a set of power-flow cases that may occurs important event from system. Case studies with metropolitan area of the Korean power system are presented to illustrate the method.

• 조명전기설비학회논문지
• /
• 제25권3호
• /
• pp.40-49
• /
• 2011

This paper presents novel circuit topology of half-bridge soft-switching PWM inverter type DC-DC high power converter for DC bus feeding power plants. The proposed DC-DC power converter is composed of a typical voltage source-fed, half-bridge high frequency PWM inverter with a high frequency planar transformer link PWM control scheme and parallel capacitive lossless snubbers. The operating principle of the new DC-DC converter treated here is described by using switching mode-equivalent circuits, together with its unique features. All the active power switches in the half-bridge arms and input DC bus lines can achieve ZCS turn-on and ZVS turn-off commutation transitions. The total turn-off switching losses of the power switches can be significantly reduced. As a result, high switching frequency IGBTs can actually be selected in the frequency range of 40[kHz] under the principle of soft-switching. The performance evaluations of the experimental setup are illustrated practically.

• Journal of Power Electronics
• /
• 제18권3호
• /
• pp.826-840
• /
• 2018

This paper presents a distributed maximum power point tracking (DMPPT) algorithm based on the reference voltage perturbation (RVP) method for the PV modules of a series PV string. The proposed RVP-DMPPT algorithm is developed to accurately track the maximum power point (MPP) for each PV module operating under all atmospheric conditions with a reduced hardware overhead. To study the influence of parameters such as the controller reference voltage ($V_{ref}$) and PV current ($I_{pv}$) on the PV string voltage, a small signal model of a unidirectional differential power processing (DPP) based PV-Bus architecture is developed. The steady state and dynamic performances of the proposed RVP DMPPT algorithm and small signal model of the unidirectional DPP based PV-Bus architecture are demonstrated with simulations and experimental results. The accuracy of the RVP DMPPT algorithm is demonstrated by obtaining a tracking efficiency of 99.4% from the experiment.