• Journal of Power Electronics
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• v.19 no.1
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• pp.146-157
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• 2019

The inverter is an essential part of permanent magnet synchronous motor (PMSM) drive systems. The performance of an inverter is greatly influenced by its modulation strategy. Using a proper management of modulation strategies can guarantee high performance from a PMSM under various speed conditions. Switching between modulations is a pivotal technique that determines the performance of a PMSM. Most works on hybrid methods focus on two-level induction motors drive systems. In this paper, in order to improve the performance of PMSMs under various speed conditions, a hybrid method of a pulse width modulation (PWM) control scheme based on a neutral-point-clamped (NPC) three level topology was proposed. This hybrid PWM modulation comprised space vector PWM (SVPWM) and selective harmonic elimination PWM (SHEPWM). Under low speed conditions, the SVPWM is employed to cause the PMSM to start smoothly, and to obtain a rapid response from the control system. Under high speed conditions, the SHEPWM is employed to reduce the switching frequency and to eliminate particular current harmonics. Moreover, the harmonic characteristics of different modulations are analyzed to obtain a smooth transition between the SHEPWM and the SVPWM. Experimental and simulation results indicated the effectiveness of the proposed control method.

• Proceedings of the KIPE Conference
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• 2004.07b
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• pp.625-629
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• 2004

This paper presents a systematical approach to study carrier based PWM techniques (CPWM) in diode-clamped and cascade multilevel inverters by using a proposed named multi-modulating pattern method. This method is based on the vector correlation between CPWM and the space vector PWM (SVPWM) and applicable to both multilevel inverter topologies. A CPWM technique can be described in a general mathematical equation, and obtain the same outputs similarly as of the corresponding SVPWM. Control of the fundamental voltage, vector redundancies and phase redundancies in multilevel inverter can be formulated separately in the CPWM equation. The deduced CPWM can obtain the full vector redundancy control, and fully utilize phase redundancy in a cascade inverter In this continued part, it will be deduced correlation between CPWM equations in multi-carrier system and single carrier system, present the mathematical model of voltage source inverter related to the common mode voltage and propose a general algorithm for multi-modulating modulator. The obtained theory will be demonstrated by simulation results.

• Journal of Power Electronics
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• v.10 no.5
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• pp.468-476
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• 2010

This paper proposes and develops a new direct voltage control (DVC) approach. This method is designed to be applied in various applications for AC drives fed with a three-phase voltage source inverter (VSI) working with a constant switching time interval as in the standard direct torque control (DTC) scheme. Based on a very strong min(max) criterion dedicated to selecting the inverter voltage vector, the developed DVC scheme allows the generation of accurate voltage forms of waves. The DVC algorithm is implemented on a dSPACE DS1104 controller board and then compared with the space vector pulse width modulation technique (SVPWM) in an open loop AC drive circuit. To demonstrate the efficiency of the developed algorithm in real time and in closed loop AC drive applications, a scalar control scheme for induction motors is successfully implemented and experimentally studied. Practical results prove the excellent performance of the proposed control approach.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.12
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• pp.1119-1124
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• 2013

In this paper we propose a novel torque control method for permanent magnet synchronous motors using the SVPWM (Space Vector PWM). The control law is described in the rotating d-q frame and is devised to track a given reference flux with which the reference torque is generated. The key feature of the proposed control is that it provides uniform dynamics with desired closedloop poles independent of the rotating speed and the desired poles can be selected to yield a fast response with only a small amount of torque ripple.

• The Transactions of the Korean Institute of Power Electronics
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• v.10 no.4
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• pp.339-346
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• 2005

It is complex to realize the reference voltage vector by the space vector PWM method in three-leg two-phase inverter In this paper a new PWM technique for three-leg two-phase inverter fed two-phase induction motor is poroposed assuming that three-leg two-phase inverter is equivalent circuit for 'four-leg two-phase inverter with the connected two windings'. From assumption, six sectors are decreased to four sectors, and simple sinusoidal PWM method instead of SVPWM is applied to three-leg two-phase inverter. Also, the switching pattern to determine the switching periods at each sector is proposed. Practical verification of theoretical predictions is presented to confirm the capabilities of the new techniques.

• The Transactions of the Korean Institute of Power Electronics
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• v.10 no.4
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• pp.331-338
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• 2005

In this paper the novel pulsewidth modulation(PWM) technique for the two-leg and four-leg two-phase inverter is proposed. The conventional space vector PWM technique for two-phase inverter was complex. The proposed PWM for two-leg inverter, which is used by sinusoidal PWM method, is simpler than the conventional SVPWU technique. Also, a simple PWM technique for four-leg two-phase inverter is proposed. Such PWM technique is based on PWM technique for two-leg inverter. Practical verification of theoretical predictions is presented to confirm the capabilities of the new techniques.

• Journal of Electrical Engineering and Technology
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• v.4 no.2
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• pp.219-228
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• 2009

The growing application and the numerous qualities of induction motors (1M) in industrial processes that require high security and reliability levels has led to the development of multiple methods for early fault detection. However, various faults can occur, such as stator short-circuits and rotor failures. Traditionally the diagnosis machine is done through a sinusoidal power supply, in the present paper we study experimentally the effects of the rotor failures, such as broken rotor bars in function of the ac supplying, the load and show the impact of the converter from diagnosis of the machine. The technique diagnosis used is based on the spectral analysis of stator currents or stator voltages respectively according to the types of induction motor ac supplying. So, four different ac supplying are considered: ${\odot}$ the IM is directly by the balanced three-phase network voltage source, ${\odot}$ the IM is fed by a sinusoidal current source given the controlled by hysteresis, ${\odot}$ the IM is fed (in open loop) by a scalar control imposing through ratio V/f=constant, ${\odot}$ the IM is controlled through a vector control using space vector pulse width modulation (SVPWM) technique inverter with an outer speed loop.

• Proceedings of the KIPE Conference
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• 2004.07b
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• pp.769-773
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• 2004

Conventional SVPWM method has null switching vectors. Null switching vectors cause high common-mode voltage in induction motor drive system. The newly developed common mode voltage reduction PWM technique don't use zero switching state for inverter control. It is realized by changing software without additional hardware. Simulation and experimental results show that proposed method are reduced common mode voltage more than conventional method.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2000.11a
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• pp.219-224
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• 2000

This paper presents a ripple reduction of BLDC motor using TMS320F240. A fault of permanent magnet(PM) BLDC motor possible to miniaturization and high-output is to be difficult to reduce speed-ripple at low speed region. An existing solution is to be use of PWM waveform by PI control with computing control angle of 60$^{\circ}$. The new family of DSP controllers provides a single chip solution by integrating on-chip not only a high computational power but also, all the peripherals necessary for electric motor control. This paper gives an advanced solution of the SVPWM technique for the purpose of reducing control angel rather than 60$^{\circ}$. This technique gives an excellent speed ripple characteristic.

• Proceedings of the IEEK Conference
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• 2002.06e
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• pp.219-222
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• 2002

There are screw, reciprocating type turbo compressor by structure in an air compressor which is essential equipment on the industrial spot. Recently, the application range of a turbo compressor tend to be wide gradually. And this type of compressor needs high speed rotation of impeller in structure so high ratio gearbox and conventional induction motor driving required. This mechanical system have results of increased moment of inertia and mechanical friction loss. Recent studies of modern turbo compressor have been applied to developing super high speed BLDC motor and driver which remove gearbox that make its size small and mechanical friction loss minimum. To accomodate this tendency, we tried to develope a super high speed motor drive system for 150Hp, 70,000rpm direct drive Turbo compressor using DSP(Digital Signal Processor) and SVPWM(Space Vector Modulation PWM) technique. The results of this specific application show that super high speed driver and controller could be implemented well with digital electronics.