• Journal of international Conference on Electrical Machines and Systems
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• v.1 no.3
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• pp.347-353
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• 2012

Design and analysis of a novel 2-phase 4/5 Switched Reluctance Motor(SRM) is presented. The proposed motor employs a novel stator pole configuration. A novel SRM employs four-rotor and five-stator poles. The motor has no dead-zone and can be operate at any rotor position. The structure and operating principle are also described. The comparison between the proposed motor and a conventional two-phase 4/2 SRM is undertaken in this analysis. Furthermore, the Finite Element Analysis(FEA) and matlab-simulink are used to predict and simulate the performance of a proposed motor. The results of investigation indicate that the proposed structure offers a better performance in term of torque production.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.2
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• pp.138-147
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• 2009

In this paper, improved direct torque control(DTC) system for five-phase squirrel-cage induction motor(IM) is proposed. Due to the additional degrees of freedom, five-phase 1M drives present unique characteristics. Also five-phase motor drives possess many other advantages compared with the traditional three-phase motor drive system, such as reducing an amplitude of torque pulsation and increasing the reliability. The DTC 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 into the three-phase inverter. However, five-phase motor has structural drawback of 3rd space-harmonics current component, it is necessary to controlled 3rd harmonic current. So to control 3rd harmonic current and enhance dynamic characteristics of five-phase squirrel-cage IM drive, modified DTC method should be demanded. The characteristics and dynamic performance of traditional five-phase DTC are analyzed and new DTC for five-phase IM is presented. A more precise flux and torque control algorithm for the drives can be suggested and explained For presenting the superior performance of the proposed direct torque control, experimental results are presented using a 32-[bit] fixed point TMS320F2812 digital signal processor with 2.2[kW] induction motor.

• Journal of the Korea Safety Management & Science
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• v.17 no.4
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• pp.403-410
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• 2015

This study documents the 3-phase BLDC(Brushless DC) motor to improve conventional exhaust fan motor. Energy efficiency, noise, and air pollution reduction for the high-performance vibration of the BLDC motor has been used in many fields. It is necessary to achieve the information of rotor position for driving 3-phase type brushless DC motor. It is also necessary that the PWM control algorithm design for a MOSFET driver to control the motor speed control for each of three phases. BLDC motors for exhaust fan, we studied the controller and software. The control circuit and motor control program through which Exhaust fan up close and person can be used safely and protect the environment.

• Journal of Electrical Engineering and Technology
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• v.10 no.3
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• pp.905-915
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• 2015

Two PWM techniques using space vector pulse-width modulation (SVPWM) are proposed for a two-phase permanent magnet synchronous motor (PMSM) driven by a two-phase eight-switch inverter. A two-phase motor with two symmetric stator windings is usually driven by a two-phase four-, six-, or eight-switch inverter. Compared with a four- and six-switch inverter, a two-phase eight-switch inverter can achieve larger power output. For two-phase motor drives, the SVPWM technique achieves more efficient DC bus voltage utilization and less harmonic distortion of the output voltage. For a two-phase PMSM fed by a two-phase eight-switch inverter under a normal SVPWM scheme, each of the eight PWM trigger signals for the inverter have to be changed twice in a cycle, causing a higher PWM frequency. Based on the normal SVPWM scheme, two effective SVPWM schemes are investigated in order to reduce the PWM frequency by rearranging four comparison values, while achieving the same function as the normal PWM scheme. A detailed explanation of the normal and two proposed SVPWM schemes is illustrated in the paper. The experimental results demonstrate that the proposed schemes achieve a better steady performance with lower switching losses compared with the normal scheme.

• Journal of Power Electronics
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• v.19 no.3
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• pp.761-770
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• 2019

This paper proposes a hybrid phase windings excitation method for improving the efficiency of a 7-phase brushless DC (BLDC) motor in the electric propulsion system of a ship. The electrical losses of a BLDC motor system depend on the operating region and the number of excited phase windings (2-phase, 4-phase or general 6-phase windings). In this paper the operating region and torque/speed characteristics according to the motor rotation speed and propeller load are analyzed for a number of excitation methods. In addition, it analyzes the electrical losses of the system under each of the excitation methods in the entire operating region of the motor. In every sampling time, the proposed control method calculates the electrical loss of the system for each of the excitation methods and operates a 7-phase BLDC motor by selecting the excitation method that results a decreased electrical loss at the operating speed. The usefulness of the proposed control algorithm is verified through experimental results.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.12
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• pp.2127-2134
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• 2007

The simulation model has been already developed not for 7 phase but for 3 phase BLDC motor. It is necessary to develop a new simulation model of multi-phase BLDC motor including the phase delay angle especially in the high speed region. In this paper, the suitability of the proposed model is verified through the several computer simulations, and experimented results.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.8
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• pp.1186-1192
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• 2015

This paper proposes an economical method that the phase currents can be measured and reconstructed by means of the leg-shunt resistors in the 3-leg 2-phase vector-controlled inverter for 2-phase induction motor. In general, the phase currents of 2-phase induction motor have been measured using two Hall current sensors. However, because Hall current sensors are expensive, economically disadvantageous to apply in low power applications. The proposed method is verified by computer simulations and experiments to show the good performance of the vector control.

• Fire Science and Engineering
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• v.26 no.1
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• pp.61-67
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• 2012

In the three-phase power system using the three-phase motor, when any one-phase is open-phase, the unbalanced current flows and the single-phase power supplied by power supply produces overcurrent to motor coil. As a result, the enormous damage and electrical fire can be given to the power system. Recently, the thermal over-current relay (THR) or electronic motor protection relay (EMPR) is mostly used as the open-phase detection device of the three-phase motor. When the over-current or overheat of electric line is generated, it detects and operates circuit breaker, but there is the defect that the sensing speed is slow, the operation can be sometimes failed, and the precision is decreased. In order to improve these problems, this paper is proposed a new control circuit topology for openphase protection using semiconductor devices. Therefore, the proposed open-phase protection device (OPPD) enhances the sensing speed and precision, and has the advantage of simple fitting in the three-phase motor control panel in the field, as it manufactures into small size and light weight. As a result, the proposed OPPD protects the three-phase motor, minimizes the electrical fire from openphase, and contributes for the stable driving of the power system. The performance and confidence of the proposed OPPD is confirmed by a great variety of the experiments of operation characteristic.

• Journal of Advanced Marine Engineering and Technology
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• v.22 no.4
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• pp.538-550
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• 1998

The variable frequency and variable voltage AC source made by a conventional inverter which is composed of power semi-conductors includes much noises in sine wave due to high frequency switching of DC source. In this paper the 3rd low pass LC filter for a variable speed 3 phase induction motor driven by a full bridge inverter is introduced to solve the EMI problem by serious noise current. The utility of a modified 3rd order Butterworth LC filter is confirmed through FFT analysis of sine waves and noiseless ACsource can be obtained by the proposed LC filter. The speed of a 3 phase induction motor driven by a full bridge inverter with a LC filter is satisfactorily controlled by a digital PID controller under the condition of stepwise load and setpoint changes.

• Proceedings of the KIEE Conference
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• 1989.11a
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• pp.5-9
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• 1989

In this paper, while 2-or 3-phase induction motor is driven with balance and no noise driving at dynamic and steady state condition. Single-phase induction motor is driven with pulsating torque except specific driving point. So we analyze the reason of producing pulsating torque with the view of unsymmetring concept. These results are applied to the design of high efficincy, high quality single-phase induction motor.