EPE Association: EPE 2009 - Subtopic 11-2 - LS: 'Adjustable Speed Drives'

EPE 2009 - Subtopic 11-2 - LS: 'Adjustable Speed Drives'
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2009 - Conference > EPE 2009 - Topic 11: 'Adjustable Speed Drives' > EPE 2009 - Subtopic 11-2 - LS: 'Adjustable Speed Drives'

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   An Advanced Multilevel Inverter with a Regenerative Unit for Motor Drives
By Koichiro NAGATA, haruo NEMOTO, Toshio KATAYAMA [View]
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Abstract: A new H-bridge cascaded multilevel inverter which can do regenerative action for motor drive is proposed. The proposed system adds a regenerative unit to the usual non-regenerative cascaded inverter, and the zero-sequence voltage is controlled to keep the regenerated power constant. In this case about 20\% of capacitance of the rated motor power is enough for the proposed unit to decelerate motor as fast as the acceleration rate for the fun drive. In this paper some simulation and numerical analysis are shared to show its availability.

   Dead-Time Effects in Voltage Source Inverter Fed Multi-Phase AC Motor Drives and Their Compensation
By Martin JONES, Drazen DUJIC, Emil LEVI, Slobodan VUKOSAVIC [View]
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Abstract: Inverter dead-time effects have been investigated in detail in the past for three-phase drives supplied from a three-phase voltage source inverter (VSI). A similar study has never been conducted in conjunction with multi-phase (more than three phases) drives, supplied from multi-phase VSIs. Regardless of the type of ac machine and its number of phases, the power supply of the drive is typically a two-level VSI, which requires a method of PWM for its operation. If a multi-phase machine is with sinusoidal field distribution, the PWM technique must generate sinusoidal harmonic-free output voltages in order to avoid appearance of low-order stator current harmonics. Recently a great deal of research has concentrated on PWM methods suitable for multi-phase VSIs. All of these PWM methods theoretically produce sinusoidal output voltages with no low order harmonics. As a consequence, rotor flux oriented control of multi-phase ac machines with sinusoidal MMF distribution can be theoretically realised by using only two current controllers in the synchronous reference frame. The paper shows that despite using a PWM method that does not produce low-order harmonics, in practice they do appear in the output voltage, and consequently currents, of the multi-phase VSI. Simulation studies show that low-order harmonics are generated as a result of inverter dead-time and that the effect of such harmonics on a five-phase ac machine can be significant due to the low machine impedance presented to these harmonics. Experimental results collected from a five-phase induction motor drive laboratory prototype are presented which reinforce this hypothesis. The paper further suggests a modified current control scheme that is able to fully compensate inverter dead-time effect and thus provide practically perfect sinusoidal currents. The proposed current control scheme is validated via simulation and experimentally.

   Real-Time Simulation of PMSM Drive in Faulty Modes with Validation an Against Actual Drive System
By Masaya HARAKAWA, Christian DUFOUR, Shunichi NISHIMURA, Tetsuaki NAGANO [View]
[Download]

Abstract: This paper presents real-time simulation results of a Permanent Magnet Synchronous Machine (PMSM) Drive in faulty and non-standard modes and validates these against an actual industrial PMSM drive system. The paper will put emphasis on the test of special and faulty modes in PMSM drives. Results of real-time simulation of a PMSM drive with an open phase and in passive mode (with all IGBTs switched off) will be presented.

EPE 2009 - Subtopic 11-2 - LS: 'Adjustable Speed Drives'
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2009 - Conference > EPE 2009 - Topic 11: 'Adjustable Speed Drives' > EPE 2009 - Subtopic 11-2 - LS: 'Adjustable Speed Drives'
	[return to parent folder]

	An Advanced Multilevel Inverter with a Regenerative Unit for Motor Drives By Koichiro NAGATA, haruo NEMOTO, Toshio KATAYAMA	[View] [Download]
Abstract: A new H-bridge cascaded multilevel inverter which can do regenerative action for motor drive is proposed. The proposed system adds a regenerative unit to the usual non-regenerative cascaded inverter, and the zero-sequence voltage is controlled to keep the regenerated power constant. In this case about 20\% of capacitance of the rated motor power is enough for the proposed unit to decelerate motor as fast as the acceleration rate for the fun drive. In this paper some simulation and numerical analysis are shared to show its availability.

	Dead-Time Effects in Voltage Source Inverter Fed Multi-Phase AC Motor Drives and Their Compensation By Martin JONES, Drazen DUJIC, Emil LEVI, Slobodan VUKOSAVIC	[View] [Download]
Abstract: Inverter dead-time effects have been investigated in detail in the past for three-phase drives supplied from a three-phase voltage source inverter (VSI). A similar study has never been conducted in conjunction with multi-phase (more than three phases) drives, supplied from multi-phase VSIs. Regardless of the type of ac machine and its number of phases, the power supply of the drive is typically a two-level VSI, which requires a method of PWM for its operation. If a multi-phase machine is with sinusoidal field distribution, the PWM technique must generate sinusoidal harmonic-free output voltages in order to avoid appearance of low-order stator current harmonics. Recently a great deal of research has concentrated on PWM methods suitable for multi-phase VSIs. All of these PWM methods theoretically produce sinusoidal output voltages with no low order harmonics. As a consequence, rotor flux oriented control of multi-phase ac machines with sinusoidal MMF distribution can be theoretically realised by using only two current controllers in the synchronous reference frame. The paper shows that despite using a PWM method that does not produce low-order harmonics, in practice they do appear in the output voltage, and consequently currents, of the multi-phase VSI. Simulation studies show that low-order harmonics are generated as a result of inverter dead-time and that the effect of such harmonics on a five-phase ac machine can be significant due to the low machine impedance presented to these harmonics. Experimental results collected from a five-phase induction motor drive laboratory prototype are presented which reinforce this hypothesis. The paper further suggests a modified current control scheme that is able to fully compensate inverter dead-time effect and thus provide practically perfect sinusoidal currents. The proposed current control scheme is validated via simulation and experimentally.

	Real-Time Simulation of PMSM Drive in Faulty Modes with Validation an Against Actual Drive System By Masaya HARAKAWA, Christian DUFOUR, Shunichi NISHIMURA, Tetsuaki NAGANO	[View] [Download]
Abstract: This paper presents real-time simulation results of a Permanent Magnet Synchronous Machine (PMSM) Drive in faulty and non-standard modes and validates these against an actual industrial PMSM drive system. The paper will put emphasis on the test of special and faulty modes in PMSM drives. Results of real-time simulation of a PMSM drive with an open phase and in passive mode (with all IGBTs switched off) will be presented.