• Journal of the Korean Society of Propulsion Engineers
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• v.16 no.6
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• pp.85-91
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• 2012

This paper describes the results of study on reaction of insensitive igniter in which a pyrosensor is automatically sensing the rate of risk of fire or explosion of solid rocket motor exposed to an unexpected fire and makes the rocket motor burn itself safely. The Slow Cook Off(SCO) test following the regulation of MIL-STD-2105D was carried out with a rocket motor loaded with HTPB propellant, in which a thermal pyrosensor igniter was installed. The auto-ignition temperature measured was approximately $140^{\circ}C$ and it corresponded to Type V(Burning) reaction in SCO test, while the temperature by Kissinger equation was calculated to be $165.5^{\circ}C$.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.3
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• pp.129-135
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• 2021

Switched Reluctance Motor (SRM) has a characteristic that the inductance changes very nonlinearly depending on the magnitude of the current and the relative position of the rotor and stator, and the torque is generated In consideration of these problems, many studies have been conducted on a topology for driving that can improve efficiency and performance in an existing asymmetric bridge converter in order to simplify the circuit and economic efficiency. Therefore, in this paper, we want to check the performance by comparing and analyzing each converter used by applying it as a topology for SRM driving. The driving converters applied to the comparison and analysis are Conventional C-dump, Modified C-dump, Energy efficient C-dump, Resonant C-dump converter with C-dump converter type structure and the most widely used asymmetric bridge converter and 6-Switch inverter that used for general motors.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.37 no.6
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• pp.361-367
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• 1988

In this study new design method with auxiliary slot on salient pole is proposed for the reduction of cogging torque which is the problem of corm type DC Brushless motor. And FEM(Finite element method) is adapted in trial motor which is designed by the method proposed in this paper. and learn the quantative characteristics of cogging torque. Comparing results of analysis with measurement it is porved that the proposed design has a propriety.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1440-1442
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• 2007

A high-voltage motor has had many problems due to its frequent startup, standstills and occasions of long period operation. As for a solution to the problem, many advanced countries have developed an on-line insulation diagnosis sensor and a same type of system and put them in use. Recently, even in the domestic market, a ceramic coupler has been developed and attempted to be applied in the field. This paper proposes an on-line insulation diagnosis system when operating a high-voltage motor along with the use of a domestic ceramic coupler. The proposed system is composed with a ceramic sensor, a PDMS-HM, and a Remote Monitoring System. As the result of comparing this system with a PDAS, which is an expensive full A/D method, the reliability of the system has been verified, and furthermore, it is in the process of being commercialized.

• The Transactions of the Korean Institute of Power Electronics
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• v.10 no.2
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• pp.186-193
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• 2005

This paper presents a strategy to drive built in-type spindle induction motor which is used as CNC(Computer Numerical Control) in the industry. Gopinath model flux estimator which is composed of current model to be profitable in the low speed range and voltage model to be profitable in the high speed range is used for rotor flux estimation. Moreover this paper presents to drive the spindle motor in the high speed range by using the flux weakening control. High speed operation of spindle motor in the field weakening region is verified through simulations and experiments.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.10
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• pp.786-790
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• 2012

A variety of diagnostic tests are widely applied in the field in industry to evaluate the condition of high voltage (HV) motor stator insulation. In this paper, the influence of temperature on the stator insulation diagnostic tests such as the insulation resistance, AC current, dissipation factor, and partial discharge measurements are studied and reported. The tests are performed with the HV motor stator winding temperature set between $40^{\circ}C$ to $80^{\circ}C$ in $10^{\circ}C$ intervals. It is shown that the AC current, dissipation factor, and partial discharge magnitude steadily increase with temperature, which suggests that temperature must be taken into account in the interpretation of the test results.

• The Transactions of the Korean Institute of Power Electronics
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• v.4 no.3
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• pp.285-293
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• 1999

In this paper, the novel digital frequency/phase controller, to control the invelter fed traveling wave type ultra-sonic m motor(USM) is proposed. This controller is used to control the drive frequency, phase difference and applied voltages of e each phase of the motor. Proposed digital controller has constructed with digital logic only, no more use digitallongleftarrowanalog h hybrid method of the conventional controller, in order to generate drive frequency and phase difference. Therefore, the c control system has become to velY simple structure. T\rvo types of controllers are designed, one is to control drive f frequency and phase difference, another has added voltage control function of each phase. Two full digital voltage/phase c controllers are implemented by using custom LSI and EPLD, the control pelformance and the simplicity ofthe proposed c controller is verified by expeJimental results.

• The Transactions of the Korean Institute of Power Electronics
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• v.4 no.2
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• pp.138-143
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• 1999

A new control method for the precision robust position control of a brushless DC(BLDC) motor for direct drive m motor(BLDDM) system using the asymptotically stable adaptive load torque observer is presented. A precision position c control is obtained for the BLDD motor system appro성mately linearized using the fieldlongrightarroworientation method. Many of t these motor systems have BLDD motor to obtain no backlashes. On the other hand, it has disadvantages such as the h high cost and more complex controller caused by the nonlinear characteristics. And the load torque disturbance is d directly affected to a motor shaft. To r밍ect this problem, stability analysis is calTied out using Lyapunov stability t theorem. Using this results, the stability is proved and load disturbance detected by the asymptotically stable adaptive observer is compensated by feedforwarding the equivalent CUlTent having the fast response.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.905-909
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• 2002

Commutators of a starting motor for automobiles has been produced through various processes such as forging, segmenting, and assembling. And the conventional method producing an automotive motor commutator is not appropriate for saving material and cost, because it makes each segment separated one by one. Therefore a new process design is required in oder to avoid the assembling process. In this study, a new process design of the commutator of an automotive starting motor has been carried out to save material and manufacturing time by FE analysis. In the FE analysis, three forging processes are proposed for producing the copper(ASTM Cl1000) commutators of a starting motor. And forging experiments are performed to make an unsegmented commutator in order to verify the theoretically proposed process. And then, in order to get the final product, the forged commutator is passed through various postprocessing such as resin terming, and machining. From the experimental result, the forging process proposed from the FE analysis is verified to be an economical method for producing the commutator of an automotive starting motor.

• Proceedings of the KIEE Conference
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• 1990.11a
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• pp.336-339
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• 1990

The permanent magnet synchronous motor windings are energized by sinusoidal excitation current. The frequency of the winding excitation current is synchronous with motor movement and the phase is a function of the motor position with respect to the stator. The total operational speed range of the system is substantially incresed by controlling the phase of the excitation currents at a function of the desired speed. This becomes the torque angle between stator rotating field and motor position. In this paper, torque angle control method is described for surface permanent magnet synchronous motor (SPMSM). The control circuit for realizing control method is investigated and the system test is carried out.