EPE Association: EPE 1989 - 05 - Lecture Session 1.5: SIGNAL PROCESSING

EPE 1989 - 05 - Lecture Session 1.5: SIGNAL PROCESSING
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1989 - Conference > EPE 1989 - 05 - Lecture Session 1.5: SIGNAL PROCESSING

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   NEW DEVELOPMENTS OF 3-LEVEL PWM STRATEGIES
By B. Velaerts; P. Mathys [View]
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Abstract: 3-level Pulse-Width Modulation is peculiarly adapted to the control of high-power GTO inverters for variable speed asynchronous machines. It enables to use the GTO technology with high voltage levels, while maintaining a low harmonic contents of wave forms. This paper describes the different modulation modes (asynchronous, synchronous and precalculated) that can be combined to design a modulation strategy in the frequency voltage plane. We introduce in this paper a new method of synchronous dipolar modulation. Its harmonic spectrum has been computed by means of a double Fourier series. A programmed-logic modulator has been developed. For the moment only the dipolar asynchronous and synchronous modulation have been implemented in C language. This modulator has been tested on two prototypes of inverters: the first one is based upon bipolar transistors and is rated 8 kVA, the second one uses GTO and has got a maximum power of 500 kVA. Those tests have confirmed the interesting properties of the 3-level dipolar modulations and the validity of the chosen strategy.

   QUICK RESPONSE SPACE VECTOR CONTROL FOR A HIGH POWER THREE-LEVEL INVERTER DRIVE SYSTEM
By F. Bauer; H.-D. Heining [View]
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Abstract: A signal processor based high power drive system with three-level voltage source inverter feeding an induction machine is presented. In order to achieve quick response of the complete drive system, an advanced field-oriented control technique with novel flux-calculator is employed. Precontrol networks for stator current and rotor flux regulation contributes to an excellent dynamic behaviour. To attain the megawatt range, a gate-turn-off thyristor (GTO) equipped three-level inverter is used. A new pulse width modulation (PWM) method enables high quality realization of voltages as well as high dynamic performance. The novel inverter trigger set, developed from two-level inverter control, performs an on-line calculation of three-level PWM waveforms. It effects voltage space vector approximation with optimal switching sequence of the inverters GTOs. Both, field-oriented control and generation of pulse-patterns are implemented on a digital signal processor (DSP). The necessary calculation time is short enough to enable additional tasks, e.g. identification, diagnostics, communication, etc.

   SELF-TUNING DIGITAL STATE CONTROLLER FOR A SYNCHRONOUS SERVO DRIVE USING A SIGNALPROCESSOR SYSTEM
By W. Löbe [View]
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Abstract: In machine tool applications the high dynamic performance of synchronous servo drives will cause undesired oscillations of the mechanical parts of the load. To avoid these oscillations, a state variable controller was implemented on a signalprocessor system. The necessary state variables as well as the load torque were reconstructed by an observer by means of the motor speed only. The tuning of the controller and the observer is done automatically by the signalprocessor. A special identification method based on a FFT algorithm is suggested to build up the model of the plant, which is necessary for the state observer. The procedures were proved by experimental tests with a machine tool.

   SLIDING-MODE-PlD VARIABLE STRUCTURE CONTROL OF AN AC SERVO DRIVE SYSTEM
By Chen Boshi; Zhang Linjun; Dai Shuzu; Wang Fengyao [View]
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Abstract: A microprocessor-based variable structure AC servo system with sliding mode is described, in which the boundary conditions for the existence of sliding mode is discussed and the problem of chattering is solved. In order to simplify the model of the controlled object, an inner vector controlled loop is adopted. A three step phase plane trajectory for sliding mode control is used to enhance the robustness of the system. Digital simulation and experimental results confirm that the dynamic performance of the system is insensitive to parameter variations and disturbances.

   REAL TIME MOTOR CONTROL USING A TRANSPUTER PARALLEL PROCESSOR NETWORK
By G. M. Asher; M. Sumner [View]
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Abstract: This paper assesses the performance of an INMOS Transputer parallel processing network for real time motor control. This assessment is felt to be significant since parallel architectures are likely to become increasingly exploited as the processors become cheaper, more powerful and flexible, and with enhanced system support. The questions are therefore: what are the advantages of parallel processing, and the transputer in particular, when applied to motor control? To what extent should parallelism be used either for development systems or for commercial application? The assessment is based on experience of transputer implementation of AC Induction Motor Vector Control Algorithms. These implementations are described.

EPE 1989 - 05 - Lecture Session 1.5: SIGNAL PROCESSING
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1989 - Conference > EPE 1989 - 05 - Lecture Session 1.5: SIGNAL PROCESSING
	[return to parent folder]

	NEW DEVELOPMENTS OF 3-LEVEL PWM STRATEGIES By B. Velaerts; P. Mathys	[View] [Download]
Abstract: 3-level Pulse-Width Modulation is peculiarly adapted to the control of high-power GTO inverters for variable speed asynchronous machines. It enables to use the GTO technology with high voltage levels, while maintaining a low harmonic contents of wave forms. This paper describes the different modulation modes (asynchronous, synchronous and precalculated) that can be combined to design a modulation strategy in the frequency voltage plane. We introduce in this paper a new method of synchronous dipolar modulation. Its harmonic spectrum has been computed by means of a double Fourier series. A programmed-logic modulator has been developed. For the moment only the dipolar asynchronous and synchronous modulation have been implemented in C language. This modulator has been tested on two prototypes of inverters: the first one is based upon bipolar transistors and is rated 8 kVA, the second one uses GTO and has got a maximum power of 500 kVA. Those tests have confirmed the interesting properties of the 3-level dipolar modulations and the validity of the chosen strategy.

	QUICK RESPONSE SPACE VECTOR CONTROL FOR A HIGH POWER THREE-LEVEL INVERTER DRIVE SYSTEM By F. Bauer; H.-D. Heining	[View] [Download]
Abstract: A signal processor based high power drive system with three-level voltage source inverter feeding an induction machine is presented. In order to achieve quick response of the complete drive system, an advanced field-oriented control technique with novel flux-calculator is employed. Precontrol networks for stator current and rotor flux regulation contributes to an excellent dynamic behaviour. To attain the megawatt range, a gate-turn-off thyristor (GTO) equipped three-level inverter is used. A new pulse width modulation (PWM) method enables high quality realization of voltages as well as high dynamic performance. The novel inverter trigger set, developed from two-level inverter control, performs an on-line calculation of three-level PWM waveforms. It effects voltage space vector approximation with optimal switching sequence of the inverters GTOs. Both, field-oriented control and generation of pulse-patterns are implemented on a digital signal processor (DSP). The necessary calculation time is short enough to enable additional tasks, e.g. identification, diagnostics, communication, etc.

	SELF-TUNING DIGITAL STATE CONTROLLER FOR A SYNCHRONOUS SERVO DRIVE USING A SIGNALPROCESSOR SYSTEM By W. Löbe	[View] [Download]
Abstract: In machine tool applications the high dynamic performance of synchronous servo drives will cause undesired oscillations of the mechanical parts of the load. To avoid these oscillations, a state variable controller was implemented on a signalprocessor system. The necessary state variables as well as the load torque were reconstructed by an observer by means of the motor speed only. The tuning of the controller and the observer is done automatically by the signalprocessor. A special identification method based on a FFT algorithm is suggested to build up the model of the plant, which is necessary for the state observer. The procedures were proved by experimental tests with a machine tool.

	SLIDING-MODE-PlD VARIABLE STRUCTURE CONTROL OF AN AC SERVO DRIVE SYSTEM By Chen Boshi; Zhang Linjun; Dai Shuzu; Wang Fengyao	[View] [Download]
Abstract: A microprocessor-based variable structure AC servo system with sliding mode is described, in which the boundary conditions for the existence of sliding mode is discussed and the problem of chattering is solved. In order to simplify the model of the controlled object, an inner vector controlled loop is adopted. A three step phase plane trajectory for sliding mode control is used to enhance the robustness of the system. Digital simulation and experimental results confirm that the dynamic performance of the system is insensitive to parameter variations and disturbances.

	REAL TIME MOTOR CONTROL USING A TRANSPUTER PARALLEL PROCESSOR NETWORK By G. M. Asher; M. Sumner	[View] [Download]
Abstract: This paper assesses the performance of an INMOS Transputer parallel processing network for real time motor control. This assessment is felt to be significant since parallel architectures are likely to become increasingly exploited as the processors become cheaper, more powerful and flexible, and with enhanced system support. The questions are therefore: what are the advantages of parallel processing, and the transputer in particular, when applied to motor control? To what extent should parallelism be used either for development systems or for commercial application? The assessment is based on experience of transputer implementation of AC Induction Motor Vector Control Algorithms. These implementations are described.