• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.74.5-74
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• 2001

The wave power plant is a generating system to convert the wave energy resources to electric energy. ´CHUJEON A´, which is a prototype of wave power plant developed by KORDI(Korea Ocean Research and Development Institute), has been launched for its performance test. A wound rotor induction machine is adopted as a generator for the power plant to acquire constant frequency and voltage over wide range of rotor speed. Because the generator of ´CHUJEON A´ has no connection to the power grid line on land, all of the processes to generate and consume the electricity have to be conducted on the floating plant. This paper deals with the design and implementation of the unmanned control system for ´CHUJEON A´. The system includes generator control system, power conversion and charging system, data acquisition and wireless communication system ...

• Journal of Power Electronics
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• v.16 no.6
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• pp.2192-2201
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• 2016

Wind energy is currently the fastest-growing electricity source worldwide. The cost efficiency of wind generators must be high because these generators have to compete with other energy sources. In this paper, a system that utilizes an open-winding permanent-magnet synchronous generator is studied for wind-energy generation. The proposed system controls generated power through an auxiliary voltage source inverter. The VA rating of the auxiliary inverter is only a fraction of the system-rated power. An adjusted control system, which consists of two main parts, is implemented to control the generator power and the grid-side converter. This paper introduces a study on the effect of unbalanced voltages for the wind-generation system. The proposed system is designed and simulated using MATLAB/Simulink software. Theoretical and experimental results verify the validity of the proposed system to achieve the power management requirements for balanced and unbalanced voltage conditions of the grid.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.48 no.11
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• pp.742-747
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• 1999

On-line diagnosis system has been developed and is now applied the detection of shorted turns in the field winding of large generator. This system consists of data aquisition system and display PC. The data aquisition system detects voltage waveforms from flux probe sensor installed in the stator slot. The display PC shows theshorted-turn situation of generator rotor winding. A shorted-turn diagnosis test wasperformed on five gas turbine generators at the Seoinchon combined cycle power plant. The test was conducted using an new diagnosis system and digital oscilloscope which can identify the pole location, the slot number and the number of shorted turns within each slot. It is confirmed that results of two systems are very same in the field tests.

• 한국태양에너지학회:학술대회논문집
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• 2008.04a
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• pp.43-48
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• 2008

Through simulations and field experiment on A.C. parallel operation of both Utility Interactive Photovoltaic System and Diesel Engine Revolving Field Type Synchronous Generator, following factors have been found. First, the inverter should be operated in three modes of frequency(mode.1: ${\pm}$0.3Hz, mode.2: ${\pm}$1Hz, mode.3: ${\pm}$2Hz) as default, considering properties of operating Synchronous Generator. Second, as a result of supplying 13.5kW of residual power, it has been found that Synchronous Generator takes the power input only as reactive power, because it was electrically stable with frequency of 60.14Hz and high voltage of 222.3V even when power factor was -0.94. Besides, it was mechanically stable, too, because the quake, noise, and temperature of Synchronous Generator in this case were 7.5mm/s, 97dB, and $6^{\circ}C$ respectively, which were lower than normal load connection of 145.6kW; 11.03mm/s. Thus, load share of Revolving Field Type Synchronous Generator reduces according to the supply of Photovoltaic System to the load power. In this experiment, 200kW of Synchronous Generator and 40kW of Photovoltaic System were operated in parallel. The load share was 20% in maximum. and 11.1lit/hr of fuel was saved.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.9
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• pp.1803-1810
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• 2009

This paper designed IQ imbalance estimator and compensator to cancel the IQ imbalance error in DVB-T system using OFDM by Matlab. Among Matlab model, we designed and implemented IQ imbalance estimator and compensator by System Generator of Xilinx and Matlab model compared with Xilinx System Generator Model for FPGA implementation. As a result of simulation, we confirmed that both model estimated and compensated IQ imbalance error very well. Also, we verified the performance through hardware co-simulation, timing analysis and resource estimation with Xilinx Spartan3 xc3s1000 fg676-4 target Device.

• Journal of Electrical Engineering and Technology
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• v.13 no.6
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• pp.2187-2195
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• 2018

In order to realize the multi-objective control of single-input multi-output nonlinear differential algebraic system (NDAS) and to improve the dynamic characteristics and static accuracy, a design method of nonlinear control with multi-objective feedback (NCMOF) is proposed, the principium of this method to arrange system poles, as well as its nature to coordinate dynamic characteristics and static accuracy of the system are analyzed in detail. Through NCMOF design method, the multi-objective control of the system is transformed into linear space, and then it is effectively controlled under the nonlinear feedback control law, the problem to balance all control objectives caused by less input and more output of the system thus is solved. Applying NCMOF design method to generator excitation system, the nonlinear excitation control law with terminal voltage, active power and rotor speed as objective outputs is designed. Simulation results show that NCMOF can not only improve the dynamic characteristics of generator, but also damp the mechanical oscillation of a generator in transient process. Moreover, NCMOF can control the terminal voltage of the generator to the setting value with no static error under typical disturbances.

• Proceedings of the KIPE Conference
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• 2003.11a
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• pp.247-251
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• 2003

The developments of the hybrid energy are necessary since the future alternative energies that have no pollution and no limitation are restricted. Currently power generation system of MW scale has been developed. However, even photovoltaic system cannot always generate stable output with ever-changing weather condition. In this paper, sub power generator for hybrid system(photovoltaic 500[W], wind power generation 400[W]) was suggested. Sub power Generator that uses elastic energy of spiral spring to photovoltaic system was also added for the present system. In an experiment, when output of photovoltaic system gets lower than 24[V] (charging voltage), power was continuously supplied to load through the inverter by charging energy obtained from generating rotary energy of spiral spring operates In DC generator. Also, control algorithm of sub power generator is used genetic algorithm(GA).

• Proceedings of the KIEE Conference
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• 1996.11a
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• pp.95-98
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• 1996

Response speed of generator/control system kas increased with the aid of the development of power electronics. Even though it is desirable to enhance response speed for the control system(AVR/Gov) of generator itself, in case a certain generator/control system with high response excitation system is connected with bulk power system, terminal voltage and active power of some generators can oscillate with adjoining generators or near area when even a little of disturbance take place. PSS(Power System Stabilizer) is used to damp rotor swing by adding the supplementary signal in phase with speed. As the stable AVR response is very important before PSS is installed, modeling and analysis of generator/control system was performed. Next we have analysed PSS response of Hanlim's gas turbine by transmission line open/close test.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.5
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• pp.929-935
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• 2009

As modem industrialized society progresses, the demand for electric power is increasing rapidly. The electric power system is getting amazingly bigger and complicated, which can easily induce serious troubles from the potential of large fault problems and/or system failure. The monitoring and diagnosis of the electric machine for the fault detection and protection has been important part in the electric power system. Most faults in the generator appear in the winding. This paper presents the air-gap magnetic flux characteristic of a small-scale 2-pole synchronous generator according to the faults in the field winding to protect the generator from the fault. The magnetic flux patterns in air-gap of a generator under various fault conditions as well as a normal state are simulated by using finite element method. These results are successfully applied to the detection and diagnosis of the short-circuit condition in rotor windings of a high capacitor generator.

• 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.