• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.3 no.3
• /
• pp.651-659
• /
• 1999

This Paper Proposes new speed and electromagnetic torque control of an induction motor, which is robust against time varying parameters. The control is based on adaptive vector control with serial block adaptive algorithm. Motor parameters used to estimates slip frequency and electromagnetic torque. Parameters mismatch in the control system detrimentally affects slip frequency estimation and torque response. In order to compensate lot degradation of the responses, an adaptive identifier for the magnetizing inductance and the secondary time constant is introduced. adaptive vector control system consisted of two subsystems, a vector control system realized on synchronous frame and a parameter identification system on stationary frame. the effectiveness of the proposed method was verified by some digital simulations.

• Journal of Electrical Engineering and Technology
• /
• v.6 no.4
• /
• pp.527-534
• /
• 2011

In the present paper, the characteristics of Mega-Flux$^{(R)}$, JNEX-Core$^{(R)}$, amorphous and ferrite cores are compared to the inductor of buck-boost converters for Hybrid Electric Vehicles. Core losses are analyzed at the condition of 10 kHz sine wave excitations, and permeability fluctuations vs. temperature and magnetizing force will be analyzed and discussed. Under the specifications of the buck-boost converter for 20 kW THS-II, the power inductor will be designed with Mega-Flux$^{(R)}$ and JNEX-Core$^{(R)}$, and informative simulation results will be provided with respect to dc bias characteristics, core and copper losses.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.64 no.3
• /
• pp.159-163
• /
• 2015

Recently squirrel cage induction generator has been steadily applied to many small hydro power plants. Induction generator needs a reactive power for magnetization. The reactive power of induction generator is being supplied from the supply side mostly. The use of induction generators in the power distribution grid can affect the power factor. The power factor of induction generator is fixed already during production. The power factor in the distribution system is due to the increase or decrease of the load rather than due to the induction generator. In this study, we analyzed that how the increase or decrease of D/L load impacts at the change of power factor and power flow.

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.53 no.7
• /
• pp.382-388
• /
• 2004

The most widely used primary protection for the internal fault detection of power transformers is current percentage differential relaying(PDR). However, the harmonic components could be decreased by magnetizing inrush when there have been changes to the material of iron core or its design methodology. The higher the capacitance of high voltage status and underground distribution, the more differential current includes the second harmonic component during occurrence of an internal fault. Therefore, the conventional harmonic restraint methods need modification. This paper proposes an advanced protective relaying algorithm by fluxt-differential current slope characteristic and trend of voltage and differential current. To evaluate the performance of proposed algorithm, we have made comparative studies of PDR fuzzy relaying, and DWT relaying. The paper is constructed power system model including power transformer, utilizing the WatATP99, and data collection is made through simulation of various internal faults and inrush. As the results of test. the new proposed algorithm was proven to be faster and more reliable.

• Journal of the Korean Society for Precision Engineering
• /
• v.19 no.10
• /
• pp.107-113
• /
• 2002

To monitor the torque of an induction motor using current, rotating speed has been measured and used to calculate the slip angular velocity. Additional sensor, however, can cause extra expense and trouble. In this paper, a new algorithm is proposed to monitor the torque of vector controlled induction motor without any speed measuring sensor. Only stator current is measured to estimate the magnetizing current which is used to calculate flux linkage, rotor velocity and motor torque. Graphical programming is used to implement the suggested algorithm and to monitor the torque of an induction motor in real time. To solve the fluctuation problem of estimated torque caused from instantly varying rotating speed of an induction motor, the rotating speed is reconstructed based on the measured current signals. From several experiments, the proposed method shows a good estimation of the motor torque under the normal rotational speed.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.28 no.3
• /
• pp.238-244
• /
• 2004

To monitor the torque of an induction motor using current, the accurate identification of the motor parameters is very important. In this study, the motor parameters such as rotor resistance, stator and rotor leakage inductance, mutual inductance are estimated for torque monitoring and indirect vector control. Estimated parameters are used to monitor the torque of vector controlled induction motor without any speed measuring sensor. Stator current is measured to estimate the magnetizing current which is used to calculate flux linkage, rotor velocity and motor torque. From the experiments, the proposed method shows a good estimation of the motor parameters and torque under the normal rotational speed.

• Proceedings of the KIPE Conference
• /
• 1998.10a
• /
• pp.944-949
• /
• 1998

This paper presents a new high-performance intelligent controlled current-source (CCS) system which can compensate for modelling errors of armature resistance, leakage and magnetizing inductances and for space harmonic components of speed EMF's. A shuttle-motion simulation is presented in the mass-reduced-mode in which an equivalent vehicle weight is reduced, by 40kg to 7kg. This study provides one of the most important key-tech-nologies in driving practical linear synchronous motor (LSM) Maglev vehicle.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.5 no.2
• /
• pp.149-153
• /
• 2000

Recently, some works to consider the influences of iron loss have been made in vector control of induction m motor. This paper investigates the effects of iron loss in stator flux-oriented system, and presents the control a algorithm to consider iron loss. The iron loss is modeled by equivalent iron loss resistance in parallel to m magnetizing inductance. The proposed method is verified by simulation and experimental results.

• Proceedings of the KIEE Conference
• /
• 2002.11d
• /
• pp.128-130
• /
• 2002

This paper describes the operating characteristic analysis of magnetic actuator that is used in breaker using 3-D axisymmetry finite element method. To analyze the operating characteristic of magnetic actuator for configuration change is designed an A, B model and C. Also, For Transient analysis of Electromagnetic system is considered Non-linear characteristic for magnetizing of iron. The analysis results of A, B model and C for magnetic actuator compared with those characteristic respectively.

• Proceedings of the KIEE Conference
• /
• 2000.07b
• /
• pp.1300-1302
• /
• 2000

In the charge system, a contact type-convenient-charging method is insufficient because of the contact failure around moist environment and troublesome question to put in and pull out. For the solution of this problem, an electromagnetically coupled non-contact charger for the rechargeable cell is proposed using ZVS multi-resonant forward converter. In this paper magnetizing inductance, leakage inductance and coupling coefficient, k are observed. By using the obserbed value, the proposed circuit is simulated by the PSPICE and implemented and the peak voltage of switch and output power are measured.