• The Transactions of the Korean Institute of Electrical Engineers B
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• v.51 no.8
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• pp.475-481
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• 2002

In this paper the new converter topology using single-Phase full bridge inverter for the switched reluctance motor drives is proposed. The proposed SRM drives are supplied by the AC pulse voltage source, while the conventional drives are supplied by the DC voltage source. Speed of the SRM is controlled by adjusting the frequency and the multitude of output current of inverter. The SRM using the proposed converter reduces the switching loss and the machine core loss, and has ability to pre-regulate the input voltage. The total number of power switches become fewer than another topology as a number of stator poles becomes more. Power circuit of an inverter is simpler and its volume is smaller because the module device involving several switches is used as an inverter.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.36 no.1
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• pp.3-8
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• 1987

The conventional autosequentially commutated current-fed inverter (ASCI) is widely employed with the induction motor drives for speed control. Howener, this inverter has a limit of high power and high frequency indution motor drives. One of the limitations is to be found in the commutation capacitors in the main circuit of this inverter. A new current-fed gate turn-off thyristor (GTO) inverter is developed. This inverter is composed of the main GTO bridge configuration and the improved energy rebound circuit (ERC)without the commutation capacitor. This inverter works stable at high frequency from light load to heavy one. The improved ERC is used not only to rebound the load reactive power to the dc link, but also to return the power in the load to the ac source. The new GTO inverter circuit and the characteristics of the inverter induction motor drives are explained and analyzed.

• Proceedings of the KIPE Conference
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• 1998.10a
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• pp.535-540
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• 1998

This paper discusses a triple stage current source GTO inverter system for high power motor drives. The energy rebound circuit of the triple stage inverter not only controls the spike voltage of the GTO inverter but also facilitates PWM control of the thyristor rectifier operated at unity fundamental input power factor. Based on Pspice simulation and experiments, the principles and PWM pulse pattern for removing specific lower harmonics in the inverter's output current are discussed in detail.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.989-991
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• 2001

The new converter topology using full bridge inverter for the switched reluctance motor drives is proposed. The proposed SRM drives are supplied by the pulse voltage source, while the conventional drives are supplied by dc voltage source. Proposed converter maintains the characteristics of asymmetric bridge converter and has advanced characteristics.

• Proceedings of the KIEE Conference
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• 2001.04a
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• pp.335-337
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• 2001

The new converter topology using half bridge inverter for the switched reluctance motor drives is proposed. The proposed SRM drives are supplied by the pulse voltage source, while the conventional drives are supplied by de voltage source. Proposed converter does not lose the characteristics of classic converter though the total no. of power switches are reduced.

• Journal of Power Electronics
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• v.9 no.3
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• pp.481-490
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• 2009

This paper describes a SVPWM overmodulation scheme of NPC type three-level inverter for traction drives which extends the modulation index from MI=0.907 to unity. SVPWM strategy is organized by two operation modes of under-modulation and over-modulation. The switching states under the under-modulation modes are determined by dividing them with two linear regions and one hybrid region the same as the conventional three-level inverter. On the other hand, under the over-modulation mode, they are generated by doing it with two over-modulation regions the same as the conventional over-modulation strategy of a two level inverter. Following the description of over-modulation scheme of a three-level inverter, the system description of a vector controlled induction motor for traction drives has been discussed. Finally, the validity of the proposed modulation algorithm has been verified through simulation and experimental results.

• 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.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.

• The Transactions of the Korean Institute of Power Electronics
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• v.24 no.2
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• pp.120-126
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• 2019

This study proposes a neutral voltage balance control scheme for stable fault-tolerant operation of an active neutral point clamped (ANPC) inverter using carrier-based pulse width modulation. The proposed scheme maintains the neutral voltage balance by reconfiguring the switching combination and modulating the reference output voltage in order to solve the degradation of the output characteristic in the fault tolerant operation due to the fault of the power semiconductor switch constituting the ANPC inverter. The feasibility of the proposed control scheme is confirmed by HIL experiment using RT-BOX.

• Proceedings of the KIPE Conference
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• 1998.07a
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• pp.10-13
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• 1998

In this paper, a control strategy of the three phase ZVT inverter for ac motor drives is proposed. The topology of ZVT inverter analyzed with a description of the control conditions dependent on the load current and MSVM(Modified Space Vector Modulation). The detailed simulation results indicate that zero-voltage operation during transition of the MSVM algorithm can be achieved.