• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.3
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• pp.123-128
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• 2021

For accurate speed and current control in industrial applications, SRM (Switched Reluctance Motor) is very important to synchronize the stator phase excitation and rotor position in the drive due to its nature. In general, position sensors such as encoder and resolver are used to generate rotational force by exciting the stator winding according to the rotor position and to control the motor by using speed and position information. However, for these sensors, 1) the cost of the sensors is quite large in terms of price, so the proportion of the motor system to the total system cost is high. 2) In terms of mechanical, position sensors such as encoders and resolvers are attached to the stator to increase the size and weight. In conclusion, in order to drive the SRM, control based on the rotor position information should be basically performed, and it is important to design the SRM driving system according to the environment in consideration of the application field. Therefore, in this paper, we intend to study the driving and control characteristics of SRM through variable switching duty control by designing a low-cost analog driving device, deviating from the general control system using the conventional encoder and resolver.

• Proceedings of the KIEE Conference
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• 2008.11b
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• pp.95-97
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• 2008

The binary observer estimates the rotor position and rotor flux with alleviation of the high-frequency chattering, and retains the benefits achieved in the conventional sliding observer, such as robustness to parameter and disturbance variations. The position sensorless control of SRM under the load and inductance variation is verified by the experimental results.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.11B no.4
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• pp.175-179
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• 2001

The switched reluctance drive exhibits higher levels of vibration and acoustic noise than that of most competing drives. The main source of vibration in the switched reluctance drive is generated by rapid change of radial force when phase current is extinguished by commutation action. A new excitation strategy for a Switched Reluctance Motor with Auxiliary Winding (SRMAW) is described and tested. This scheme has auxiliary winding with one diode which is sound to all th poles in one winding. In this scheme, auxiliary winding is used to reduce magnetic stress during commutations. The abrupt change of a phase excitation produces mechanical stresses and it results in vibration and noise. The acoustic noise is reduced remarkably through 2-stage commutation. The operational principle and a characteristic comparison to that of the conventional SRM show that this scheme has some advantages including noise reduction as well as high efficiency drive.

• Journal of Electrical Engineering and Technology
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• v.13 no.5
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• pp.1978-1985
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• 2018

In this paper, a novel single-phase hybrid switched reluctance motor (HSRM) is proposed for hammer breaker application. The hammer breaker requires only unidirectional rotation and high-speed operation. To satisfy the requirements and eliminate torque dead-zone, the rotor of the proposed 4/4 poles SRM is designed with wider pole arc and non-uniform air-gap. This motor has a simple structure and produces low torque ripple. Permanent magnets (PMs) are mounted on the inner stator at a certain position which enables it to park the rotor for self-start and create positive cogging torque in the torque dead-zone. Compared with conventional single-phase switched reluctance motor, HSRM has an increased torque density and relatively low torque ripple. To verify effectiveness, finite element method (FEM) is employed to analyze the performance of the proposed structure. Then, the proposed motor is compared with the existing motor drive system for the same application. The proposed HSRM is easy to manufacture along with competitive performance.

• The Transactions of the Korean Institute of Power Electronics
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• v.10 no.4
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• pp.388-396
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• 2005

SRM has not been put into practical applications widely because of its large torque ripple, acoustic noise and low power factor. In addition, a traditional position sensor is needed for the drive control. So we propose an improved sensorless drive method of Switched Reluctance Motors using impressed voltage pulses. Conventional impressed voltage pulse method has a problem of phase delay because of low-pass filter. So in this paper we propose an unproved sensorless driving method based on the impressed voltage pulse using new pulse-shift circuit technique that overcomes the phase delay and start-up problem. Proposed method is implemented in a simple analog circuit instead of using an expensive DSP.

• Journal of Electrical Engineering and Technology
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• v.9 no.2
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• pp.478-488
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• 2014

Torque pulsation mechanism and highly nonlinear magnetic characterization of switched reluctance motors(SRM) lead to unfavorable torque ripple and limit the variety of applications in industry. In this paper, a modification method proposed for torque ripple minimization of SRM based on conventional torque sharing functions(TSF) to improve maximum speed of torque ripple-free operation considering converter limitations. Due to increasing phase inductance in outgoing phase during the commutation region, reference current tracking can be deteriorated especially when the speed increased. Moreover, phase torque production in incoming phase may not be reached to the reference value near the turn-on angle in which the incremental inductance would be dramatically decreased. Torque error for outgoing phase can cause increasing the resultant motor torque while it would be negative for incoming phase and yields reducing the motor torque. In this paper, a modification method is proposed in which phase torque tracking error for each phase under the commutation added to the other phase so that the resultant torque remained in constant level. This yields to extend constant torque region and reduce peak phase current when the speed increased. Simulation and experimental results for four phase 4 KW, 8/6 SRM validate the effectiveness of the proposed scheme.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.6
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• pp.109-115
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• 2008

This paper proposes an adaptive Dynamic Matrix Control (DMC) and its application to boiler-turbine system In a conventional DMC, object system is described as a Step Response Model (SRM). However, a nonlinear system is not effectively described as a single SRM. In this paper, nine SRMs at various operating points are prepared. On-line interpolation is performed at every sampling step to find the suitable SRM. Therefore, the proposed adaptive DMC can consider the nonlinearity of boiler-turbine system. The simulation results show satisfactory results with a wide range operation of the boiler-turbine system.

• Journal of Electrical Engineering and Technology
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• v.5 no.4
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• pp.571-579
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• 2010

This paper reviews and analyzes converters for SRM(Switched Reluctance Motor) drive. Conventional classification focuses on the number of power switches and diodes. It is easy to find the number of semiconductors and the cost by counting the number of active components, but it does not show the important characteristics of a power converter. The voltage ratings for the power switches and diodes are also difficult to identify. This paper proposes a switched reluctance (SR) converter configuration that is classified based on the commutation type and magnetic energy path. The converter has three parts: utility interface, front-end circuit, and power converter. Based on the overview on the conventional SR drive, the most important characteristic of the converter is determined by the topology of front-end in conjunction with the power converter. An SR converter has two parts: front-end and power converter. Inasmuch as the capacitive front-end is widely used for voltage source converters, this paper focuses on topologies for the front-end.

• Journal of Electrical Engineering and Technology
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• v.13 no.3
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• pp.1138-1146
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• 2018

Performance comparisons of switched reluctance motor for cooling fan application are dealt in this paper. Conventional and novel segmental type motors with the same dimension are compared. The conventional 12/8 type is very popular and used widely. The structure of segmental rotor type motor is constructed from a series of discrete segments, and the stator is constructed from two types of stator poles: exciting and auxiliary poles. This type of motor has short flux path and no flux reversal in the stator. The auxiliary poles are not wound by the windings and only provide the flux return path. Compared with conventional SRM, the segmental structure increases electrical utilization of the machine and decreases core losses, which leads to higher efficiency. To verify the segmental structure, finite element method (FEM) is employed to get static and dynamic characteristics of both SRMs. Finally, the prototypes of conventional and segmental SRMs are tested for characteristics comparisons.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.11B no.4
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• pp.151-155
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• 2001

The simple motor construction and low cost, fault tolerant power electronic drive has made the switched reluctance drive a strong contender for many applications. But the switched reluctance drive does exhibit higher levels of vibration and acoustic noise than that of most competing drives. The main source of vibration in the switched reluctance drive is generated by rapid change of radial magnetic force when phase current is extinguished during commutation action. In this paper, a hybrid excitation method is proposed to reduce vibration and acoustic noise of the switched reluctance drive. The hybrid excitation has 2-phase excitation by long dwell angle as well as conventional 1-phase excitation. The vibration and acoustic noise are reduced because the scheme reduces abrupt change of excitation level by distributed and balanced excitation.