EPE Association: EPE 1987 - 28 - Lecture Session 5.1: HARMONICS

EPE 1987 - 28 - Lecture Session 5.1: HARMONICS
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1987 - Conference > EPE 1987 - 28 - Lecture Session 5.1: HARMONICS

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   AN AC-DC CONVERTER WITH LOW-HARMONICS INPUT CURRENT
By H. Le-Huy; J. P. Ferrieux; E. Toutain [View]
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Abstract: Not available

   ANALYSIS OF DISTORTED UNBALANCED WAVEFORMS IN INVERTER DRIVES
By G. Andria; A. Dell'Aquila; L. Salvatore [View]
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Abstract: In the paper we propose a new method of analysing the distorted waveforms of an unbalanced three-phase voltage system. The method permits us to obtain the positive and negative sequence components of each harmonic system present in the three phases. In this way it is possible to have information both on the degree of unbalance and on the distortion factor of the waveforms generated by PWM inverters supplying induction motors.

   ON-LINE MEASUREMENT OF HIGHLY DISTORTED THREE-PHASE SUPPLY
By A. De Carli; R. Micheletti [View]
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Abstract: The paper proposes a new approach for the on-line measurement of quantities characterizing an highly distorted three-phase supply. These quantities are the RMS value of voltages and currents together with their residual oscillation and the active, reactive and harmonic power. This latter is a new quantity for measuring the effect of the supply distortion while the other ones can be easily defined by extending conventional approaches. The relations for computing these quantities by direct processing the sampled values of voltages and currents are given. These relations are connected with the conventional ones formulated in terms of the harmonic content of voltages and currents. Finally the algorithm for the on-line computation is applied to an inverter fed induction motor and the results are presented.

   COMPENSATION OF THE CYCLOCONVERTER INPUT CURRENT HARMONICS USING ACTIVE POWER FILTER
By T. Nakajima; E. Masada; Y. Ogihara [View]
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Abstract: Cycloconverter drives used for low-speed, high-torque a.c. machines such as the rolling mills in the steel industry generate non-integer order harmonics, "interharmonics". Under variable-frequency operation, the interharmonic spectrum also changes. To suppress these harmonics, the application of the active power filter is researched. In order to improve the active power filter's compensation characteristics for interharmonics, a novel scheme for the measurement of the harmonics is proposed. Numerical analysis studies verify that interharmonic currents from a cycloconverter in an industrial drive can be measured fast enough and precisely with this scheme. The measurement scheme is based on the digital signal processing and easily realized with the computer software.

EPE 1987 - 28 - Lecture Session 5.1: HARMONICS
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1987 - Conference > EPE 1987 - 28 - Lecture Session 5.1: HARMONICS
	[return to parent folder]

	AN AC-DC CONVERTER WITH LOW-HARMONICS INPUT CURRENT By H. Le-Huy; J. P. Ferrieux; E. Toutain	[View] [Download]
Abstract: Not available

	ANALYSIS OF DISTORTED UNBALANCED WAVEFORMS IN INVERTER DRIVES By G. Andria; A. Dell'Aquila; L. Salvatore	[View] [Download]
Abstract: In the paper we propose a new method of analysing the distorted waveforms of an unbalanced three-phase voltage system. The method permits us to obtain the positive and negative sequence components of each harmonic system present in the three phases. In this way it is possible to have information both on the degree of unbalance and on the distortion factor of the waveforms generated by PWM inverters supplying induction motors.

	ON-LINE MEASUREMENT OF HIGHLY DISTORTED THREE-PHASE SUPPLY By A. De Carli; R. Micheletti	[View] [Download]
Abstract: The paper proposes a new approach for the on-line measurement of quantities characterizing an highly distorted three-phase supply. These quantities are the RMS value of voltages and currents together with their residual oscillation and the active, reactive and harmonic power. This latter is a new quantity for measuring the effect of the supply distortion while the other ones can be easily defined by extending conventional approaches. The relations for computing these quantities by direct processing the sampled values of voltages and currents are given. These relations are connected with the conventional ones formulated in terms of the harmonic content of voltages and currents. Finally the algorithm for the on-line computation is applied to an inverter fed induction motor and the results are presented.

	COMPENSATION OF THE CYCLOCONVERTER INPUT CURRENT HARMONICS USING ACTIVE POWER FILTER By T. Nakajima; E. Masada; Y. Ogihara	[View] [Download]
Abstract: Cycloconverter drives used for low-speed, high-torque a.c. machines such as the rolling mills in the steel industry generate non-integer order harmonics, "interharmonics". Under variable-frequency operation, the interharmonic spectrum also changes. To suppress these harmonics, the application of the active power filter is researched. In order to improve the active power filter's compensation characteristics for interharmonics, a novel scheme for the measurement of the harmonics is proposed. Numerical analysis studies verify that interharmonic currents from a cycloconverter in an industrial drive can be measured fast enough and precisely with this scheme. The measurement scheme is based on the digital signal processing and easily realized with the computer software.