• The Transactions of the Korean Institute of Electrical Engineers B
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• v.49 no.7
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• pp.494-499
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• 2000

In a conventional stator flux-oriented(SFO) induction machine drive system, the field weakening method is to vary flux reference in proportion to the inverse of the rotor speed. This paper investigates that maximum torque capability cannot be obtained in the conventional system and proposes a new selection method of flux reference to obtain maximum torque capability over the field weakening region by considering voltage, torque, and current limits.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.6
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• pp.872-877
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• 2015

The Permanent Magnet (PM) machine used at speed control using field-weakening control method. But the field-weakening current, which reduces the field flux for high speeds, causes significant copper and core losses. Therefore, this paper deals with the PM performance evaluations in a pole changing memory motor (PCMM). The PCMM can change the number of magnetic poles and produce two types of torque. When the motor operates with eight poles, it produces a magnetic torque at low rotational speeds. When the motor changes to four poles, it produces both magnetic torque and reluctance torque at high speeds. The paper explain the principle and basic characteristics of the motor by using a finite element method magnetic-field analysis, which consists of a PM magnetized by a pulse d-axis current of the armature winding. The results of our experiment show that the proposed motor reduces core loss by 10% and 55% under no-load and load conditions, and doubles the speed range of the motor.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.779-784
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• 2001

For electrical vehicles, switched reluctance drives present a promising alternative-compared to asynchronous and synchronous (permanent magnet) concepts. For these applications, a very wide field weakening range is a key issue. Other requirements include high torque output from a small machine and low current ripple at the DC-side without the use of bulky filters - when powered from fuel cells or advanced Lithium-Ion-batteries. A new converter and control strategy according to these requirements is presented and compared to existing designs. The comparison is done for a drive system with a continuous power rating of 30 to 40 kW.

• Proceedings of the KIEE Conference
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• 1991.11a
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• pp.167-170
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• 1991

The back e.m.f. of PMSM is increased as the speed is increased and it saturates the current regulator because it counteracts the available output voltage of the inverter. In the PM motor, however, the required armature terminal voltage can be reduced within the maximum output voltage of the inverter by field weakening control, in which the air gap flux is weakened by the d-axis armature current. In this paper, the field weakening control of the surface PMSM fed by a hysteresis current control led PWM inverter based on the microprocessor is presented. To show the validity of the proposed control method, the simulation and experimental results are provided.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.13 no.2
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• pp.39-45
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• 1999

In case of field weakening region, torque is directly affected by flux. In this region, the flux reference is cIecreased inversely proportional to the rotor speed. As the flux is decreased, the magnetizing inductance is nonnally increased The increased magnetizing inductance limited voltage for controlling current In this paper, rreasuring q axis voltage in field weakening region, magnetizing inductance in flux calculating can be readjusted. Computer simulation and experiment results demostrate the efficacy of the prqx>sed rrethod. Proposed algorithm is expected to the application of the adjustable drive system in the spinning and weaving field. field.

• 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.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.13 no.2
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• pp.171-171
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• 1999

In case of field weakening region torque is directly affected by flux. In this region the flux reference is decreased inversely proportional to the rotor speed. As the flux is decreased the magnetizing inductance is normally increased. The increased magnetizing inductance limited voltage for controlling current. In this paper, measuring q axis voltage in field weakening region magnetizing inductance in flux calculating can be readjusted. Computer simulation and experiment results demonstrate the efficacy of the proposed method. Proposed algorithm is expected to the application of the adjustable drive system in the spinning and weaving field.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.1051-1053
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• 1993

In this paper, the new flux weakening contol algorithm for the drive system of Interior Permanent Magnet Synchronous Motor(IPMSM) is proposed which includes the feedback of torque and current The torque error is used in order to control the current phase angle in the field weakening control. The proposed control method is compared with the stator flux oriented vector control method. Through the simulation the prominence of the proposed control method is verified.

• The Transactions of the Korean Institute of Power Electronics
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• v.18 no.6
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• pp.540-546
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• 2013

The induction motor is used for driving the special equipments such as warship and submarine pump due to robust structure and simple maintenance. Domestic and foreign warships use a wide range of voltages and the DC voltage sources mainly from battery. In the low voltage level, the ${\Delta}$-connection operation of induction motor can be used for the maximum power. However, the temperature of the inverter increases because of the high input current. On the other hand, Y-connection operation of the induction motor does not cause a problem of temperature because of the low input current compared to the ${\Delta}$-connection. But the lack of the supply voltage can not be avoided. Therefore, this paper suggests the algorithm of the optimum field weakening control to extend the operating range of the induction motor with maximum power in a limited thermal and DC voltage condition.

• Proceedings of the KIPE Conference
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• 2012.11a
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• pp.217-218
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• 2012

A load motor used for warship or submarine is with limited volume and weight, also specific environmental tests like impact, vibration, noise, temperature and EMC/EMI have to be satisfied. Induction motors, synchronous motors, BLDC motor and etc, are used depending on the purpose of using military equipment. Induction Motors are used for a number of military equipment more commonly due to the robust structure and simple maintenance. Domestic and foreign warships have a wide range of voltages as the DC voltage sources with battery are mainly used for them. The ${\Delta}-connection$ operation of the induction motor is required to make the maximum power in a low voltage level. But the elements' temperature of the inverter increases due to high input current when it is in the ${\Delta}-connection$ operation. Therefore, the induction motor must be driven with the Y-connection. The lack of voltage needs to be with the field weakening control. This paper suggests the optimum field weakening control algorithm to drive the induction motor with maximum power in a limited thermal and DC voltage condition.