• The Transactions of the Korean Institute of Power Electronics
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• v.14 no.1
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• pp.38-45
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• 2009

To get the constant output, synchronous generator field excitation is controlled by AVR(Automatic Voltage Regulator). Most of ships generator AVR uses the thyristor phase controlled rectifier. However this rectifier is difficult to realize that the fast control system because its control period is slower than MOSFET and IGBT type converter. Therefore, this paper deals with PMG(Permanent Magnet Generator) type digital AVR using MOSFET switch for ships synchronous generator. The composition of this digital AVR is very simple, the generator is under the short circuit accident, the output voltage becomes zero state and AVR can not operate. Thus generator is required to add CBC(Current Boosting Circuit) in an excitation circuit to flow output current. The performance of the proposed system is evaluated on a 10[kVA] experimental prototype circuit in place of real ships generator.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.246-247
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• 2015

Type of Automatic Voltage Regulator (AVR) can be divided into Analog and Digital Type. Automatic Voltage Regulator (AVR) of the synchronous generators of the brushless type are to be reduced to the voltage fluctuation on the basis of the total load. The PID control method is a general control technique is commonly widely used. In this study, the control target parameter iPID does not reset the parameters of the controller for the variable (Intelligent PID) using the controller synchronous generator Digital automatic voltage to you like all applied to the adjusting device (AVR) the voltage change is small, improved responsiveness was studied in this controller.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.1
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• pp.39-44
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• 2016

Automated voltage regulators (AVRs) are used on ships and offshore to automatically adjust the voltage based on real-time output voltage readings of the generator engine. Analog-type AVR was previously more commonly used, but is slowly being replaced with digital-type AVR because of increased demands of response time. This study presents a new digital AVR system that contains appropriate features of the AVR with respect to offshore unstable load conditions and poor operating conditions. Furthermore, experiments of load and voltage change prove the excellence of stability and response of the proposed system compared to previous AVR systems. Additionally, an integrated control system for a monitoring the output voltage and field current was developed to easily set the gain value.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.11a
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• pp.225-229
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• 2007

The output voltage of a synchronous generator is regulated constantly by field current control of excitation system. Synchronous generator exciter has two type, first one is Drop control type by thyristor and second one is exciter current control type through power output by PWM control. Control method of the second one prevails, but when the power devices have a breakdown, output voltage of the generator rises rapidly. This exciter must have a protection circuit and system is complicated, so reliability is poor Excitation control type which is drop control type control only 10% of the power, so it can be improved precision. When a trouble come to the controller, output voltage of a generator don't rise excessively and the voltage rise about 10%, so it has a excellent reliability. This paper prove stability of the digital AVR.

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.136-138
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• 2008

The output voltage of synchronous generator is regulated constantly by field current control in excitation system. Most of ship generator exciter system uses the thyristor phase controlled rectifier. However this rectifier is difficult to realize that the speed control system because its control period is slower than MOSFET and IGBT type converter. Therefore, this paper deals with PMG(Permanent Magnet Generator) type digital excitation system using MOSFET for ship synchronous generator. The organization of this excitation system is very simple. When the generator is under the short circuit accident, the output voltage becomes zero state and AVR can not operate. Thus generator requires the function for flowing output current through CBS. The performance of the proposed system is evaluated on a 10kVA experimental prototype circuit in place of real ship generator.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.4
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• pp.397-403
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• 2009

In this paper, an exciter current control of a synchronous generator for ships using a compound type digital automatic voltage regulator (DVAR) in order to provide a constant output voltage of the generator is presented. The compound type DAVR is composed of a controller part to adjust output voltage and an power source unit to supply power to the exciter. The controller part, which generates the PWM switching pattern via the PI controller, drives a power MOSFET for bypass to limit the SG's exciter current. The power source unit part is parallel connected to an output terminal of the generator through a reactor and a power CT. The residual magnetic flux of SG provides exciter current to the exciter through the reactor during the initial running or no load state and load current supplies field current to the exciter through the power CT during loading state. This paper confirmed an experiment to verify the validity of compound type DAVR system for controlling output voltage of synchronous generator.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.11
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• pp.2534-2539
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• 2015

Method for regulating voltage using a generator voltage regulating device (AVR) is divided in an existing analog system and a digital replacement. Typically, to adjust the voltage by using a brushless excitation system of the type to be reduced for a voltage change under all. The control method of the AVR as a PID (proportional-integral-differential) control method is widely used. However, the control scheme is to reduce the transient response of the control parameters of the controller to the control object. Therefore, if the control target should change, there is a problem, reset the parameters of the controller again. In this study, without having to reset the parameters of the controller for the parameter variations to be controlled iPID (intelligent PID) using a controller designed to obtain a generator AVR system voltage variation is small in response to full load is applied to and through simulations and experiments improved transient response.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1417-1422
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• 2005

Among the sensors mainly used for displacement measurement, there are a linear CCD(Charge Coupled Device) and a PSD(Position Sensitive Detector) as a non-contact type. Their structures are different very much, which means that the signal processing of both sensors should be applied in the different ways. Most of the displacement measurement systems to get the 3-D shape profile of an object using a linear CCD are a computer-based system. It means that all of algorithms and mathematical operations are performed through a computer program to measure the displacement. However, in this paper, the developed system has microprocessor and other digital components that make the system measure the displacement of an object without a computer. The thing different from the previous system is that AVR microprocessor and FPGA(Field Programmable Gate Array) technology, and a comparator is used to play the role of an A/D(Analog to Digital) converter. Furthermore, an ATC(Automatic Threshold Control) algorithm is applied to find the highest pixel data that has the real displacement information. According to the size of the light circle incident on the surface of the CCD, the threshold value to remove the noise and useless data is changed by the operation of AVR microprocessor. The total system consists of FPGA, AVR microprocessor, and the comparator. The developed system has the improvement and shows the better performance than the system not using the ATC algorithm for displacement measurement.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.7
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• pp.1289-1295
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• 2007

In this paper, we implemented high-performance concurrent control system which manages whole RF systems with digital type and communicates with remote station on both wire and wireless networking. It consists of FPGA (Field Programmable Gate Array) part which controls forward/reverse LPA (Linear Power Amplifier), forward/reverse LNA (Low Noise Amplifier), channel cut wire/wireless TCP/IP, etc, master microprocessor (AVR), which manages the whole control system, Slave microprocessor which communicates SA (Spectrum Analyzer) and observes frequency spectrum of each channel with the resolution of 5KHz, 10 channel card microprocessor which independently observes each channel card and sets frequency synthesizer in channel cut and other peripherals and logics. The whole system is divided to two parts of H/W (hardware) and S/W (software) considering operational efficiency and concurrency, and implementation and cost. H/W consists of FPGA and microprocessor. We expected the optimized operation through H/W and SW co-design and hybrid H/W architecture.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.10
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• pp.867-873
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• 2002

We have designed and fabricated the slidacs type automatic voltage regulator(SVR) that is able to control the output voltage continuously according to load variation. Especially, the frictions between the surface of contact of the slidacs coils and the output wire moving shaft arc reduced by modifying the mechanical configuration of surface of contact of slidacs from the conventional sliding one into the proposed rotary one composed of cylindrical bearing. Thus, SVR using cylindrical bearing proposed in this study has less noise than the conventional one owing to the reduction of friction, and its breakdown ratio caused by the abrasion of contact materials is reduced as well. We have designed U motor driving circuit for controlling the output wire moving shaft, and introduced the digital control method using the pulse width modulation(PWM) output for controlling DC motor.