• Journal of Power Electronics
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• v.14 no.5
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• pp.989-999
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• 2014

High-performance Current Source Inverter (CSI)-fed, variable speed alternating current drives are prepared for various industrial applications. CSI-fed Induction Motor (IM) drives are managed by using different control methods. Noteworthy methods include scalar Control (V/f), Input-Output Linearization (IOL) control, Field-Oriented Control (FOC), and Direct Torque Control (DTC). The objective of this work is to compare the dynamic performance of the aforementioned drive control methods for CSI-fed IM drives. The dynamic performance results of the proposed drives are individually analyzed through sensitivity tests. The tests selected for the comparison are step changes in the reference speed and torque of the motor drive. The operation and performance of different vector control methods are verified through simulations with MATLAB/Simulink and experimental results.

• Journal of Power Electronics
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• v.13 no.5
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• pp.806-813
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• 2013

This paper aims to compare the performance of three phase induction motor drives using Five Leg Inverter (FLI) and Three Leg Inverter (TLI) configurations. An Indirect Field Oriented Control (IFOC) method using a TLI is well established and incorporated for high performance speed drives in various industries. The FLI dual motor drive system on the other hand shows good workability in the independent control of two induction motor drives simultaneously. In this experiment, the IFOC method is utilized for both drive systems, and Space Vector Pulse Width Modulation (SVPWM) is used to generate pulses for both inverters. For the FLI, the Double Zero Sequence (DZS) Injection technique is used to generate the modulation signal. The complete experiment setup is done by using a DSpace 1103 controller board. The individual motor performances are analyzed using similar schemes, equipment setups and controller parameter values. The results show similar speed performance response capability between the single motor operation using a TLI system and the two motor operation using a FLI system based on the variable speed range either in forward or reverse operation. They also show similar load rejection abilities. However, the single motor with a TLI has a better power quality aspect such as ripple current and total harmonics distortion (THD).

• Journal of Electrical Engineering and Technology
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• v.2 no.4
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• pp.500-504
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• 2007

In this paper, the induction motor rotor fault diagnosis system using current signals, which are measured using axis-transformation method, and speed, which is estimated using current information, are presented. In inverter-fed motor drives unlike line-driven motor drives the stator currents have numerous harmonics components and therefore fault diagnosis using stator currents is very difficult. The current and speed signal for rotor fault diagnosis needs to be precise. Also, high resolution information, which means the diagnosis system, demands additional hardware such as low pass filter, high resolution ADC, encoder and etc. Therefore, the proposed axis-transformation and speed estimation method are expected to contribute to low cost fault diagnosis systems in inverter-fed motor drives without the need for an encoder and any additional hardware. In order to confirm validity of the developed algorithms, various experiments for rotor faults are tested and the line current spectrum of each faulty situation using Park transformation and speed estimation method are compared with the results obtained from fast Fourier transforms.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.11
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• pp.81-86
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• 2012

It is well known that the stator-flux-oriented induction motor drives are not dependent on parameter detuning in constant torque region except low speed range. This paper presents parameter detuning effects of stator-flux-oriented induction motor drives in constant torque region. The detuning effects of stator resistance, rotor resistance and rotor leakage inductance are analyzed.

• Journal of Advanced Marine Engineering and Technology
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• v.31 no.4
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• pp.417-424
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• 2007

This paper presents a solution that an analytical model for an induction motor and the formula of regenerative power and instantaneous torque are derived. based on the spiral vector. The torque is controlled linearly through variations of the slip angular velocity, based on the field acceleration method (FAM). And also PWM inverter fed induction motor drives is schemed to be easily a regenerative drive. The voltage source inverter fed induction motor drives that regenerative power occurs with back current type is presented, to easily controlled the feedback power and to proper the adaption of energy shaving drives. The experimental tests verify the performance of the FAM, proving that food behavior of the drive is achieved in the transient and steady state operating condition, and are discussed to save the power that regenerative power is measured at the operating acceleration or deceleration of servo system.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.53 no.2
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• pp.90-98
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• 2004

Variable-speed drives are being continually innovated. Recently, sensorless induction motor drives have been much studied due to several advantages. Most sensorless algorithms are based on the mathematical modeling of motors, and all the information is obtained from the monitored voltages and currents. Therefore, the accuracy of such variables largely affects the performance of a sensorless induction motor drive. However, the output voltage of the SVPWM-VSI which is widely used in a sensorless induction motor drive has a considerable error, especially in a low speed range. This paper proposes a variation of the dc link voltage as a high-performance strategy for overcoming the above problem. The proposed strategy leads to an improved resolution of the output voltage of the SVPWM-VSI in a sensorless induction motor drive. Simulation and experiment have been performed for the verification of the proposed strategy.

• Journal of Power Electronics
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• v.7 no.4
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• pp.271-277
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• 2007

In this paper, an induction motor rotor fault diagnosis system using current signals, which are measured using the axis-transformation method is presented. Inverter-fed motor drives, unlike line-driven motor drives, have stator currents which are rich in harmonics and therefore fault diagnosis using stator current is not trivial. The current signals for rotor fault diagnosis need precise and high resolution information, which means the diagnosis system demands additional hardware such as a low pass filter, high resolution ADC, an encoder and additional hardware. Therefore, the proposed axis-transformation method is expected to contribute to a low cost fault diagnosis system in inverter-fed motor drives without the need for any additional hardware. In order to confirm the validity of the developed algorithms, various experiments for rotor faults are tested and the line current spectrum of each faulty situation, using the Park transformation, is compared with the results obtained from the FFT(Fast Fourier Transform).

• Journal of Electrical Engineering and Technology
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• v.4 no.2
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• pp.266-271
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• 2009

In this paper, improved direct torque control(DTC) of five-phase induction motor(IM) is proposed. Due to the additional degrees of freedom, five-phase IM drives present unique characteristics. One of them is the ability of enhancing the torque producing capability of the motor. Also five-phase motor drives possess many others advantage compared with the traditional three-phase motor drives. Such as, reducing the amplitude and increasing of frequency of torque pulsation, reducing amplitude of current per phase without increasing the voltage per phase and increasing the reliability. The direct torque control method is advantageous when it is applied to the five-phase IM. Because the five-phase inverter provides 32 space vectors in comparison to 8 space voltage vectors by the three-phase inverter. The 32 space voltage vectors are divided into three groups according to their magnitudes. The characteristics and dynamic performance of traditional five-phase DTC are analyzed and new DTC for five-phase IM is proposed. Therefore, a more precise flux and torque control algorithm for the five-phase IM drives can be suggested and explained. For presenting the superior performance of the pro-posed direct torque control, experimental results is presented using a 32 bit fixed point TMS320F2812 digital signal processor

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.428-433
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• 2001

This paper presents the control algorithm for maximum efficiency drives of an induction motor system with the high dynamic performance. This system uses a simple model of the induction motor that includes equations of iron losses. The model, which only requires the parameters of induction motor, is referred to a field-oriented frame. The minimum point of the input power can be obtained at the steady state condition. The reference torque and flux currents for the vector control of induction motors are calculated by the optimal efficiency control algorithm. The drive system with the proposed efficiency optimization controller has been implemented by a 32 bit floating point TMS320C32 DSP chip. The results show the effectiveness of the control strategy proposed for the induction motor drive.

• Proceedings of the KIPE Conference
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• 2019.11a
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• pp.96-97
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• 2019

Pulse Width Modulation (PWM) is a widely adopted technique to drive the motor using the voltage source inverters. Since they generate high frequency Common Mode (CM) Voltage, a high shaft voltage in induction motor is induced which leads to parasitic capacitive currents causing adverse effects such as premature deterioration of ball bearings and high levels of electromagnetic emissions. This paper presents an Active Cancellation Circuit (ACC) which can significantly reduce the CM voltage hence the common mode current in the three phase induction motor drives. In the proposed method the CM voltage is detected by the capacitors and applied to the frame of the motor to cancel the CM voltage hence the CM current. Unlike the conventional methods the proposed method does not insert the transformer in between the inverter and motor, a high power rating three phase transformer is not required and no losses associated with it. In addition the proposed method is applicable to any kind of PWM motor drives regardless of their PWM methods. The effectiveness of the proposed method is proved by the experiments with a three phase induction motor (1.1kW 415V/60Hz) combined with a three phase voltage source inverter modulated by the Space Vector Modulation (SVM).