• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.16 no.5
• /
• pp.223-229
• /
• 2023

This Paper propose the method that measure main system parameters for PI(proportional-integral) current control of a.c. motor adopting the vector control technique. For current control, the PI control input is could be tuning by several selective methods. Among the several methods, the method that using the main system parameters, wire resistance and inductance, are frequently used. In this study, the technique to dissect and measure these two system parameters through the results of simple feedback control. This analytic measurement method is measuring parameters step by step dissecting the results of P control using simple proportional feedback gain about the unit step or multiple step reference command. This strategy is an real time analytic measurement method that calculate current control gains of torque component and flux component both for vector control of A.C. motor without introducing the further measurement circuits and complex measuring algorithms.

• Journal of the Korean Society for Railway
• /
• v.3 no.1
• /
• pp.1-11
• /
• 2000

In this paper, the IGBT VVVF inverter for 1C4M propulsion system of railway traction is studied. The inverter is consisted of IGBT stacks, a DB unit, and a control unit. The test results of the combined system is given, which shows an excellent performance of the overall system.

• Proceedings of the KSR Conference
• /
• 2005.11a
• /
• pp.332-337
• /
• 2005

In order to investigate performance changes, the acceleration, vibration, and braking performance tests were carried out on the electric multiple units (EMUs) with over 20 years operation. According to the testing results, in vibration and braking performance, the similar performance results were obtained as compared with newly manufactured EMUs. However, in terms of acceleration performance, below reference value (3.0 km/h/s) has been obtained. This is mainly due to performance deterioration including traction motor. The precision diagnosis evaluation of deteriorated EMUs will be provided through the overall evaluation of corrosion testing and structural performance of car body.

• Proceedings of the KIEE Conference
• /
• 2011.07a
• /
• pp.1234-1235
• /
• 2011

A DC Power Distribution Systems(DC PDS) are widely used in telecommunication system, electric vehicle, aircraft, military system, etc. In the DC PDS, DC bus voltage instability may be occurred by the operation of multiple loads such as pulsed power load, motor drive system, and constant power loads. To damp the transients of the DC bus voltage, the Voltage Bus Conditioner(VBC) with the PI compensator is used. In this paper, the validity of the proposed VBC system is verified by PSIM simulation package.

• Journal of the Korean Society of Safety
• /
• v.13 no.4
• /
• pp.256-263
• /
• 1998

In this paper, we propose a volume holographic fingerprint recognition system based on optical correlator for personal identification. Optical correlator has high speed and parallel processing characteristics of optics. Matched filters are recorded into a volume hologram that can store data with high density, transfer them with high speed, and select a randomly chosen data element. The multiple reference images of database are prerecorded in a photorefractive crystal in the form of Fourier transform images, simply by passing the image displayed in a spatial light modulator through a Fourier transform lens. The angular multiplexing method for multiple holograms of database can be achieved by rotating the crystal by use of a step motor. Experimental results show that the proposed system can be used for the security verification system.

• International Journal of Ocean Engineering and Technology Speciallssue:Selected Papers
• /
• v.6 no.1
• /
• pp.30-37
• /
• 2003

This paper describes vibration control of a suspended system using wave absorption method. A moving multiple-pendulum system and a moving wire-and-load system are treated. The wire-and-load system is extended to a model crane system that has a motor system to roll up and down the suspended mass like a real crane. The same program with different parameter values controls these three systems. Both numerical simulation and experiment have been conducted, and the present control method has shown to be quite effective.

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.48 no.4
• /
• pp.444-451
• /
• 1999

A diagnostic rule-base design method for enhancing fault detection and isolation performance of multiple obsever based fault detection isolation schemes (FIDS) is presented. The diagnostic rule-base has a hierarchical framework to perform detection and isolation of faults of interest, and diagnosis of process faults. The decision unit comprises a rule base and a fuzzy inference engine and removes some difficulties of conventional decision unit which includes crisp logic with threshold values. Emphasis is placed on the design and evaluation methods of the diagnostic rult-base. The suggested scheme is applied to the FDIS design for a DC motor driven centrifugal pump system.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2004.11a
• /
• pp.999-1004
• /
• 2004

In this study, we identify contribution of structure-borne-noise of vehicle HVAC system using Multi-Dimensional spectral analysis (MDSA) method. Firstly, to identify the applicability of MDSA method, the case of HVAC system was modeled with four input / single output system. The four inputs which is given vibration data is composed of blower, evaporator, heater and duct. The single output is noise data from driver's seat. When the blower motor is operating, we analyze the contributions of four input / single output. As a result of experiment, we identify efficiency of systems modeled with four input / single output through ordinary coherence function (OCF) and multiple coherence function (MCF).

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.10
• /
• pp.221-227
• /
• 2016

This study was conducted to identify sensory processing factors that affect motor and process skills of children with cerebral palsy. A total of 36 children with cerebral palsy who attended at the J pediatric development center and the N rehabilitation hospital in Seoul participated. Pearson's correlation coefficients were used to test the relationship between motor skills, process skills and sensory processing abilities of children. Moreover, hierarchical multiple regression was used to identify the sensory processing factors influencing motor and process skills. Motor skills of children with cerebral palsy were correlated with auditory filtering, low energy/weakness, and visual/auditory sensitivity of sensory processing items, whereas process skills were correlated with tactile sensitivity and taste/smell sensitivity. The hierarchical regression model for motor skills revealed movement sensitivity, auditory filtering, and low energy/weakness as significant factors influencing sensory processing items. However, no factors were shown to influence process skills. The results of this study will be useful as a basic resource for rehabilitation of children with cerebral palsy. However, further studies evaluating a larger population should be conducted to verify the results presented herein.

• Journal of Power Electronics
• /
• v.17 no.2
• /
• pp.442-452
• /
• 2017

This paper deals with the input-output modeling of a vector controlled PMSM drive system and design of a simple multiple model adaptive control (MMAC) scheme with desired transient responses. We present a discrete-time modeling technique using closed-loop identification that can experimentally identify the equivalent models in the d-q coordinates. A bank of linear models for the equivalent plant of the current loop is first obtained by identifying them at several operating points of the current to account for nonlinearity. Based on these models, we suggest a simple q-axis MMAC combined with a fixed d-axis controller. After the current controller is designed, another equivalent model including the current controller in the speed control loop shall be similarly obtained, and then a fixed speed controller is synthesized. The proposed approach is demonstrated by experiments. The experimental set up consists of a surface mounted PMSM (5 KW, 220V, 8 poles) equipped with a flywheel load of 220kg and a digital controller using DSP (TMS320F28335).