• Journal of Electrical Engineering and Technology
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• v.10 no.2
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• pp.595-602
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• 2015

The rotor configuration of the brushless doubly fed induction generator (BDFIG) plays an important role in its performance. In order to make the magnetomotive force (MMF) space vector in one set rotor windings to couple both magnetic fields with different pole-pair and have low resistance and inductance, this paper presents a novel wound rotor type for BDFIG with low space harmonic contents. In accordance with the principles of slot MMF harmonics and unequal element coils, this novel rotor winding is designed to be composed of three-layer unequal-pitch unequal-turn coils. The optimal design process and rules are given in detail with an example. The performance of a 700kW 2/4 pole-pair prototype with the proposed wound rotor is analyzed by the finite element simulation and experimental test, which are also carried out to verify the effectiveness of the proposed wound rotor configuration.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.535-539
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• 1999

This paper presents the 2nd excitation control of the wound-rotor induction motor with Fly-wheel. In the wound-rotor induction motor, the primary power is controlled by AC excitation which used the secondary power conversion. Based on theory, this paper describes the dynamic response analysis of the wound-rotor induction motor with Fly-wheel and Simulation using MATLAB is performed to verify the proposed control method.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.166.2-166
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• 2001

This paper is concerning a vector control of wound-rotor induction motor from the secondary side. When the wound-rotor induction motor is vector controlled from the secondary side, it has the possibility that the vector control can be accurately done because the disturbance input, that is, primary voltage and all state variables, that is, primary currents and secondary currents can be detected. We consider it is deserve research that the vector control of wound-rotor induction motor from the secondary side, because there is the merit that we can reduce the inverter capacity to on the order of half of the motor capacity when we choose twice of the synchronous speed to the rated speed, though there is the problem of the brush maintenance. In this paper, the vector control method of wound-rotor induction ...

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.34-37
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• 2000

This paper presents the power compensation by wound-rotor induction motor with a Fly-wheel. In the wound-rotor induction motor the primary power is controlled by AC excitation which used the secondary power conversion. Based on theory this paper describes the dynamic response analysis of the would-rotor induction motor with Fly-wheel. Simulation and experimental results are performed to verify the proposed control method

• Journal of Power Electronics
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• v.13 no.4
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• pp.669-678
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• 2013

This paper proposes a sensorless control approach for Wound Rotor Synchronous Machines (WRSMs) based on a high frequency voltage signal injection into the stator side U phase and VW line, respectively. Considering the machine itself as a rotor position sensor, the rotor position observer is established according to the principles of the rotary transformer. A demodulation method for the high frequency signal inducted in the rotor is proposed as well. Simulation and experimental results show that the proposed sensorless control approach has high performance and good practicability.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.68 no.4
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• pp.523-531
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• 2019

This paper deals with a wound-field synchronous machines(WFSM), with an electromagnet on its salient rotor, as an alternative to a permanent magnet in the rotor. We then examine the power performance characteristics, loss characteristics, V-curves and large short-circuit ratios for a large-scale synchronous generator, considering the leading and lagging operations, based on the finite-element method. We predict the performance of a 100MVA-class generator based on the operating range for a constant short-circuit ratio. At the last, We compared with the electromagnetic characteristics of three model according to number of slots.

• Journal of Institute of Control, Robotics and Systems
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• v.3 no.6
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• pp.619-625
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• 1997

In this paper, we show that the rotor position of the bifilar-wound hybrid stepping motors for the closed-loop drives is detected by the phase current measurement. We propose an instantaneous phase current equation, which is the function of electrical angle, by modeling the stepping motor including motor driving circuits. We also analyze the relationship between phase current and rotor position from the computer simulation results. We show that the information about the rotor position is obtained from the phase current amplitude and its derivatives at the instance of ${\pi}/2$ electrical angle of excitation voltage.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.6-9
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• 2000

In wind power generating system connected in power grid the value of stator flux has almost constant because the stator side of wound rotor induction generator is connected to power grid. Using the stator and rotor current it is possible to achieve control of generating power in stator side. This means that we can control the power factor by decoupled rotor current in synchronously rotating reference frame. To verify the theoretical analysis results of computer simulation and experiment are presented to support the discussion.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.3
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• pp.40-46
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• 2009

Toroidally-wound brushless direct-current (BLOC) machines are compact, highly efficient, and can work across a large magnetic gap. For these reasons, they have been used in pumps, flywheel energy storage systems and left ventricular assist devices among others. The common feature of these systems is a spinning rotor supported by a set of (either mechanical or magnetic) bearings. From the view point of dynamics, it is desirable to increase the first critical speed of the rotor so that it can run at a higher operating speed. The first critical speed of the rotor is determined by the radial stiffnesses of the bearings and the rotor mass. The motor also affects the first critical speed if the rotor is displaced from the rotating center. In this paper, we analytically derive the flux density distribution in a toroidally-wound BLOC machine and also derive the negative stiffness of the motor, based on the assumption that the rotor displacement perturbs the flux density distribution linearly. The estimated negative stiffness is validated by finite element analyses.

• Proceedings of the KIEE Conference
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• 1997.07a
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• pp.326-329
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• 1997

This paper deals with the generating power analysis of wound rotor induction generator according to the rotor excitation for use of DFIG (Doubly Fed Induction Generator) system in wind power generation as a part of renewable energy development. In this way, the generating power of wound rotor induction generator can be achieved for a wide range wind speed of supersynchronous and subsynchronous speed.