• Proceedings of the KIPE Conference
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• 2002.11a
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• pp.181-185
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• 2002

This paper discusses power balance control of photovoltaic/wind/diesel hybrid generation system for remote area power supplies. There are many control methods for hybrid power system. Among others, it must be adopted that the control method to guarantee a stable balance between supply and demand, regardless of the fluctuation of generator power by atmospheric changes. In this paper, it Is proposed that a hybrid generation system has a power-balanced controller to equilibrate generation power with a load demand, which is composed of DC bus-type power systems. To execute power balance control, it is assumed that all of power generators have a equivalent current-source characteristics. Through the results of simulation, the proposed scheme was verified.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.7
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• pp.615-622
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• 2004

Recently, the hybrid system combining fuel cell and gas turbine has drawn much attention owing to its high efficiency and ultra low emission. It is now on the verge of world wide development and various system configurations have been proposed. A national project funded by Korean government has also been initiated to develop a pressurized hybrid system. This work aims at presenting design performance analysis for various possible system configurations as an initial step for the system development. Study focuses are given to major design options including the power ratio between gas turbine and fuel cell, reforming method (internal or external), reforming heat source (reforming burner, cathode hot air, fuel cell heat release) and steam supply method for reformer (anode gas recirculation, external steam generator). A wide variation in performance among different configurations has been predicted.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.1
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• pp.8-13
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• 2012

In this paper, Hybrid Electric Vehicle is directly designed and manufactured for base study of HEV's system and Green Car. Foundation design consists of power train design and the frame design. The power train concept includes motor, engine, generator and battery. And the concept of the frame is the single-seat of this self-made HEV. A frame installed in hybrid system contains suspension, steering wheel, seat, accelerating pedal, brake pedal, clutch handle and various chassis parts with bearings. Electromagnetic clutch is equipped to transmit engine power to drive axle. The control algorism make using LabVIEW to control of an engine and a motor depending on drive condition. A parallel type hybrid system is manufactured to control operation of a motor and an engine depending on vehicle speed.

• Journal of Power Electronics
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• v.3 no.3
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• pp.145-150
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• 2003

Reliability, availability, and cost have been the major concerns for photovoltaic hybrid systems since their beginning as primary sources for much critical applications like communication units and repeaters. This paper descnbes the performance of two hybrid systems, photovoltaic-battery, wind-turbine coupled with the public-grid (PVBWG) hybrid system and photovoltaic-battery, wind-turbine coupled With the diesel generator (PVBWD) hybrid system The systems are sized to power a typical 300W/48V de telecommunication load continuously throughout the year Such hybrid systems consist of subsystems, which in turn consist of components Failure of anyone of these components may cause failure of the entire system. The reliability and availability basics, and estimation procedure for the two proposals are introduced also in this paper. The PVBWG and PVBWD system configurations are shown with the relevant mean-time-between-faIlure (MTBF) and failure rate (${\lambda}$) of each component. The characteristics equations of the two systems are deduced as a function of operating hours and the percentage of sun and wind availabilities per day. The system probability failure as well as the reliability is estimated based on the fault tree analysis technique. The results show that, by using standard or normal components MTBF, the PVBWG is more reliable and the time of periodic maintenance period is more than one year especially in the rich sites of both sun and wind, but PVBWD competes else Also, in the first five years from the system installation, the system is quit reliable and may not require any maintenance. The results show also, as the sun and wind are available, as the system reliable and available.

• Journal of Advanced Marine Engineering and Technology
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• v.31 no.5
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• pp.583-591
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• 2007

This paper reports the performance of a 150W PV-wave hybrid system with battery storage in buoy. This system was originally designed to meet a new hybrid ower system for buoy in Korea. In the case or lighted buoys and lighthouses, a light failure alarm system of wireless radio is attached so that light failures are immediately notified to the office. At lighthouse offshore fixed lights and light buoys where commercial electricity is not available, the power source depends on solar system and batteries. This power system has a various problems. Therefore energy derived from the sunshine, wind and waves has been used as the energy source lot aids to navigation. Recently a hybrid system of combining the solar, wind and the wave generator is a favorable system lot the ocean facilities like lighthouse and buoy. The hybrid system in this paper is intended for variable DC load like light, communication system in the buoy and includes a PV-wane generation system and battery. This is composed a high efficiency charging algorithm, switching converter and controller. This paper includes discussion on system reliability, power quality, and effects of hybrid system in the buoy. Simulation and experimental results show excellent performance.

• Journal of Power Electronics
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• v.15 no.1
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• pp.246-255
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• 2015

This paper presents experimental results and its assessment of a variable-speed wind power generation system (VSWPGS) using permanent magnet synchronous generator (PMSG) and boost chopper circuit (BCC). Experimental results are obtained by a test bench with a wind turbine emulator (WTE). WTE reproduces the behaviors of a windmill by using servo motor drives. The mechanical torque references to drive the servo motor are calculated from the windmill wing profile, wind velocity, and windmill rotational speed. VSWPGS using PMSG and BCC has three speed control modes for the level of wind velocity to control the rotational speed of the wind turbine. The control mode for low wind velocity regulates an armature current of generator with BCC. The control mode for middle wind velocity regulates a DC link voltage with a vector-controlled inverter. The control mode for high wind velocity regulates a pitch angle of the wind turbine with a pitch angle control system. The hybrid of three control modes extends the variable-speed range. BCC simplifies the maintenance of VSWPGS while improving reliability. In addition, VSWPGS using PMSG and BCC saves cost compared with VSWPGS using a PWM converter.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.35 no.6
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• pp.639-646
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• 2022

Energy harvesting technologies that can convert wasted various energy into usable electrical energy have been widely investigated to overcome the limitation of batteries for the powering of IoT sensors and small electronic devices. Hybrid energy harvesting is known as a technology that enhances the output power of single energy harvesting device by housing two or more various energy harvesting mechanisms. In this study, we introduce a hybrid MME (Magneto-Mechano-Electric) generator coupled with the triboelectric effect. Through FEA modeling, four triboelectric materials, including PI (Polyimide), PFA(Teflon), Cu, and Al, were selected and compared with the expected triboelectric potentials. The effect of surface morphology was investigated as well. Among various combination of triboelectric materials and surface morphologies, PFA-Al combination with the surface morphology having nano-scale square projections showed highest output potential under triboelectrification. It is also experimentally confirmed that output voltage and power of the hybrid MME generator with triboelectric material combinations.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.6
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• pp.74-79
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• 2019

The military vehicle produces electric power through an engine-integrated serial hybrid generator that is connected to the engine and does not have a separate generator installation space. However, depending on the mechanical characteristics of the connection between the generator and the engine, iron oxide for internal rusting and lubrication grew scattered. The iron oxide is adhered to the starter to deteriorate the starting performance, and there is a problem that the noise of the leg due to wear of the gear is increased. To solve this problem, the connection spline material and the surface treatment of the engine were improved and the shape was changed to a grease sealing type to prevent the generation of iron oxide inside. As the shape of the generator connector composing the shafting system was changed, the integrity of the structure was confirmed through the torsional endurance test. In addition, through the actual vehicle load test, it was verified that no corrosion occurred during the target life span without internal corrosion. It was confirmed that the anti-scattering structure of the grease effectively suppresses the generation of iron oxide, thereby reducing the noise generated from the generator. In this paper, we propose a fundamental solution to the degradation of the starter and the noise generation by preventing the back corrosion caused by the serial hybrid generator installed between the engine and the transmission.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.439-439
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• 2009

Nowadays, source of MEMS, USN, Hybrid parts pay attention to energy harvesting. On this paper, energy harvesting was studied using piezoelectric effect. And, piezoelectric generator was designed and fabricated. Generators were designed by FEM simulation program and generators were made by attaching cymbal type metal plates on upper and bottom sides of a disc type piezoelectric ceramic. Output AC power was rectified to DC power by full bridge circuit and converted to regular voltage power by DC-DC converter. The final output power was charged to Ni-Cd battery. Using fabricated generators, output voltages dependant on thickness of ceramic, displacement of vibration, frequency of vibration were measured.

• Journal of Power Electronics
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• v.10 no.2
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• pp.194-202
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• 2010

The main cause of degradation in an unbalanced stand-alone doubly-fed induction generator (DFIG) system is negative sequence components that exist in the generated stator voltages. To eliminate these components, a hybrid current controller composed of a proportional-integral controller and a resonant regulator is developed in this paper. The proposed controller is applied to the rotor-side converter of a DFIG system for the purpose of compensating the negative stator voltage sequences. The proposed current controller is implemented in a single positive rotating reference frame and therefore the controller can directly regulate both the positive and negative sequence components without the need for sequential decomposition of the measured rotor currents. In terms of compensation capability and accuracy, simulations and experimental results demonstrated the excellent performance of the proposed control method when compared to conventional vector control schemes.