• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.2
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• pp.123-129
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• 2016

In this paper, results of produced PCU(Power Control Unit) prototype was showed by suggesting and maintaining optimal operation status which let the three functional modules automatically operate with its necessity by prioritizing operation process. In order to validate effectiveness of the suggested method, we produced a test PCU and examined the results. PCU consists of S3R(Sequential Switching Shunt Regulator), BCR(Battery Charge Regulator), and BDR(Battery Discharge Regulator): converting photovoltaic power into constant voltage at linked bus voltage; storing dump power in the battery which is an auxiliary energy storage device; and supplying power charged in battery to the load. To maintain its high reliability and optimal condition of these three power conversion modules, each module operates in parallel and stable bus voltage is required to be retained at all-time due to the nature of power supply for satellite.

• The Transactions of the Korean Institute of Power Electronics
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• v.17 no.2
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• pp.174-181
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• 2012

Energy storage system connected to the grid has two functions such as the surplus power of a grid is stored in batteries or the energy stored in batteries will supply to the grid when the grid needs. The battery energy storage system consist of power condition system (PCS) for power supply and battery conditioning system (BCS). Lithium-ion batteries are mainly used. In this paper, the battery energy storage system connected to the grid described. The configuration of the 2MVA class power control system using water cooling and battery system are presented. And control method for the system and the output filter design method are proposed. Experimental verification of the proposed system is provided with 2MVA PCS and 500kWh BCS.

• Journal of the Korean Society of Propulsion Engineers
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• v.25 no.1
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• pp.68-76
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• 2021

The series hybrid system targeted in this study uses a reciprocating engine, a generator, and a battery as a main power source for the unmanned aerial vehicle. The generator is directly connected to the drive shaft of the reciprocating engine, and the operating characteristics of the reciprocating engine-generator set were confirmed through ground integration tests. In this study, based on the test results, a control logic is proposed an efficient use of the reciprocating engine-generator power and battery power. Also, the power variations of the reciprocating engine-generator and battery according to the logic were verified through simulation. As a result, it was confirmed that the engine-generator power supplied the power required for propulsion along with the battery power by the proposed control logic.

• Proceedings of the KIPE Conference
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• 2012.07a
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• pp.232-233
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• 2012

This paper presents an effective control scheme for an electric vehicle battery charger where a symmetrical bridgeless power factor-corrected converter and a buck converter are cascaded. Both converters have been popular in industries because of their high efficiency, low cost, and compact size, hence combining these converters makes the overall battery charging system strongly efficient. Moreover, this charger topology can operate at universal input voltage and attain a desired battery current and voltage without ripple. In order to achieve a unity input power factor and zero input current harmonic distortion, the proposed control scheme adopts duty ratio feed-forward control technique in both current and voltage control loop. Additionally, in the current loop, its reference is created by a phase-locked loop (PLL) block, leading to a pure sinusoidal input current although the input voltage waveform is being distorted. The feasibility and practical value of the proposed approach are verified by simulation and experiment with an 110V/60Hz ac line input and 1.5kW-72V dc output of the battery charging system.

• Proceedings of the KIPE Conference
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• 2013.07a
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• pp.388-389
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• 2013

This paper presents the method for the fluctuation smoothing control by using relaxation time variable control of battery. When the output power of wind farm is changed suddenly, it is necessary to control the output power of wind farm. The smoothing relaxation time is changed within limits of battery output power. Using the hybrid energy storage system (HESS) combined with battery energy storage system and electric double layer capacitor, it is possible to control the output power of wind farm. The capacity of battery is determined by considering the case of the disconnecting wind farm from the grid. To verify the proposed method, simulations are carried out by using PSCAD/EMTDC with actual data of wind farm in the Jeju Island.

• Proceedings of the KIPE Conference
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• 2004.11a
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• pp.85-89
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• 2004

This paper presents Power Control and Distribution Unit development of GEO satellite with 3kW power output. The sensing error of bus voltage produce control signal of the shunt switch assembly and battery power converter, and the tolerance of error signals generated decide the stability of proposed system. The dynamic characteristics of main bus according to the load changing and the control logic of FPGA are simulated. In order to verify the proposed design, the simulation and experimental results for solar array shunt switch, battery power converter and bus controller are shown.

• Journal of Electrical Engineering and Technology
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• v.13 no.2
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• pp.742-751
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• 2018

Electric vehicles (EV) are emerging as the future transportation vehicle reflecting their potential safe environmental advantages. Vehicle to Grid (V2G) system describes the hybrid system in which the EV can communicate with the utility grid and the energy flows with insignificant effect between the utility grid and the EV. The paper presents an optimal power control and energy management strategy for Plug-In Electric Vehicle (PEV) charging stations using Wind-PV-FC-Battery renewable energy sources. The energy management optimization is structured and solved using Multi-Objective Particle Swarm Optimization (MOPSO) to determine and distribute at each time step the charging power among all accessible vehicles. The Model-Based Predictive (MPC) control strategy is used to plan PEV charging energy to increase the utilization of the wind, the FC and solar energy, decrease power taken from the power grid, and fulfil the charging power requirement of all vehicles. Desired features for EV battery chargers such as the near unity power factor with negligible harmonics for the ac source, well-regulated charging current for the battery, maximum output power, high efficiency, and high reliability are fully confirmed by the proposed solution.

• Journal of the Korean Society of Industry Convergence
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• v.24 no.4_2
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• pp.491-499
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• 2021

Batteries are widely used for energy storage, such as ESS(Energy Storage System), electric vehicles, electric aircraft, and electric powered ships. Among them, a submarine uses a high power battery for an energy storage. When the battery of a submarine is discharged, a diesel generator generates AC power, and then AC/DC power converter change AC power to DC power for charging the battery. Therefore, in order to lower the current capacity of the diesel generator, it is necessary to use an AC/DC converter with a high input power factor. And, a power converter with a large power capacity must have high stability because it can lead to a major accident when a failure occurs. However, the control algorithm using the traditional PI controller is difficult to satisfy stability and dynamic characteristics. In this paper, we design the high power AC/DC converter with high input power factor for battery charging systems. And, we propose a stable control algorithm. The validity of the proposed method is verified through simulation and experiments.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1629-1633
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• 2004

In this paper, we first implement the simulation environment to investigate the efficient control method of a Fuel Cell Electric Vehicle (FCEV) system with battery. The subsystems of a FCEV including the fuel cell system, the electric motor (including the power electronics) and the tansmission (reduction gear), and the auxiliary power source (battery) are mathematically fomulated and coded using the Matlab/Simulink software. Some examples are given to show the capabilities of the modeled system and d a basic control strategy is examined for the economic energy distribution between the fuel cell and the auxiliary power source. It is illustrated by simulations that the actual vehicle velocity follows the given desired velocity pattern while both SOC control and power distribution control are being performed.

• The Transactions of the Korean Institute of Power Electronics
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• v.5 no.5
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• pp.475-483
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• 2000

This paper describes designs about the power system of KITSAT-4 satellite. The KITSAT-4 power system is mainly composed of power stage and control stage. The power stage is a 200〔W〕 buck converter and control stages are hardware controller and software controller The hardware controller is PPT(Peak Power Tracker), battery voltage controller and software controller is battery current controller and direct duty controller. So the operation of power system has many advantages in that it can select controller according to reliable control and precise control. The controller design methods are presented and the small signal analyses are performed to verify system stability.