EPE Association: EPE 1987 - 17 - Lecture Session 2.3: SIGNAL PROCESSING (III)

EPE 1987 - 17 - Lecture Session 2.3: SIGNAL PROCESSING (III)
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1987 - Conference > EPE 1987 - 17 - Lecture Session 2.3: SIGNAL PROCESSING (III)

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   A NEW ECONOMIC THREE-PHASE PWM INVERTER FOR HIGH DYNAMIC FEED OF INDUCTION MACHINES
By C. Niermann [View]
[Download]

Abstract: A new economic medium power three-phase impulse commutated voltage source PWM inverter is presented. This two-level inverter, proposed by M. Depenbrock is especially designed for high dynamic feed of squirrel cage induction motors. The used switching elements are six asymmetrical thyristors only and diodes. This circuit is marked out by a minimum of thyristors and diodes, a short dead time and a sufficiently high clock frequency .

   New Predictive Control Stategy for PWM-Inverters
By O. Niermeyer; D. Schröder [View]
[Download]

Abstract: Applying two self-commutated inverters, one at the lineside and one at the machineside allows the full four-quadrant-operation of a speed controlled ac-motor drive at a very high total power factor on the lineside. With frequent speed changes the efficiency of the drive system is increased, due to the feedback of energy to the line. Also the lineside PWM-inverter is able to compensate reactive power demand from other parallel connected loads. The line current vector control calculates on line optimized pulse pattern to keep the three line currents within a preset hysteresis to the reference values. During steady state load condition the optimal switching state prediction results in minimized inverter losses and a low line distortion factor. Nevertheless the dynamic behaviour is only restricted by the inverter limitations.

   PWM GATE ARRAY FOR AC DRIVES
By E. Kiel; W. Schumacher; R. Gabriel [View]
[Download]

Abstract: New designs for digitally controlled AC drives include the current control loop or PWM pattern generation in digital circuitry. Inverter as well as control are digital in nature. So a circuit was designed, which interfaces between them. Primary goal in this design was to concentrate all calculations running with a high repetition rate into hardware. This includes the sine and cosine functions and multiplication with the desired amplitude. The circuit works in two operating modes. In conjunction with a simple microcontroller for frequency inverter applications only output voltage and frequency have to be transmitted to the chip. For high dynamic purposes a signal processor can operate the chip by sending a cartesian voltage vector and a phase angle thus relieving the processor trom the task of output transformation from field into stator coordinates.

   NEW PRECALCULATING CURRENT CONTROLLER FOR DC DRIVES
By Reimund Leonhard; Dierk Schroeder [View]
[Download]

Abstract: With respect fo the variing nonlinearity of a line commutated inverter the precalculating algorithm for a dc motor current control has been developed and implemented. Possible real time firing instants alpha(n) are on line examined ahead of real time to obtain a corresponding future mean value Id**(n). Comparing this future current mean value Id**(n) to the desired set point ld ref, firing instants may be derived exactly. Id**(n) will result from future current shape id**(T ,n), which is calculated in the signalprocessor using on line numerical integration of the armature differential equation. Repetetive use of the above precalculation of Id**(n) will yield a real time current controller with ideal step response no matter if the converter is operared in continuous or discontinuous mode.

   POWER CONDITIONNING AND CONCEPTUAL DESIGN OF PHOTOVOLTAIC HYBRID SYSTEMS
By Noureddine Ben Slama; Mohamed Annabi; J. P. Requier [View]
[Download]

Abstract: This paper presents a general study of the photovoltaïc hybrid systems composed of multigenerators multireceptors and battery storage unit. In order to increase the reliability and the efficiency of their functionning, the energetic resources must be managed in real time. However, this brings about certain problems that we are trying to solve. We present the optimum power conditionning of both the photovoltaïc array and the wind generator and we analyse the transcient study of the system in order to guarantee minimal phase responses of the state variables. A typical hybrid installation was chosen and the main technical choises were discussed in purpose to illustrate the designing of such a system.

EPE 1987 - 17 - Lecture Session 2.3: SIGNAL PROCESSING (III)
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1987 - Conference > EPE 1987 - 17 - Lecture Session 2.3: SIGNAL PROCESSING (III)
	[return to parent folder]

	A NEW ECONOMIC THREE-PHASE PWM INVERTER FOR HIGH DYNAMIC FEED OF INDUCTION MACHINES By C. Niermann	[View] [Download]
Abstract: A new economic medium power three-phase impulse commutated voltage source PWM inverter is presented. This two-level inverter, proposed by M. Depenbrock is especially designed for high dynamic feed of squirrel cage induction motors. The used switching elements are six asymmetrical thyristors only and diodes. This circuit is marked out by a minimum of thyristors and diodes, a short dead time and a sufficiently high clock frequency .

	New Predictive Control Stategy for PWM-Inverters By O. Niermeyer; D. Schröder	[View] [Download]
Abstract: Applying two self-commutated inverters, one at the lineside and one at the machineside allows the full four-quadrant-operation of a speed controlled ac-motor drive at a very high total power factor on the lineside. With frequent speed changes the efficiency of the drive system is increased, due to the feedback of energy to the line. Also the lineside PWM-inverter is able to compensate reactive power demand from other parallel connected loads. The line current vector control calculates on line optimized pulse pattern to keep the three line currents within a preset hysteresis to the reference values. During steady state load condition the optimal switching state prediction results in minimized inverter losses and a low line distortion factor. Nevertheless the dynamic behaviour is only restricted by the inverter limitations.

	PWM GATE ARRAY FOR AC DRIVES By E. Kiel; W. Schumacher; R. Gabriel	[View] [Download]
Abstract: New designs for digitally controlled AC drives include the current control loop or PWM pattern generation in digital circuitry. Inverter as well as control are digital in nature. So a circuit was designed, which interfaces between them. Primary goal in this design was to concentrate all calculations running with a high repetition rate into hardware. This includes the sine and cosine functions and multiplication with the desired amplitude. The circuit works in two operating modes. In conjunction with a simple microcontroller for frequency inverter applications only output voltage and frequency have to be transmitted to the chip. For high dynamic purposes a signal processor can operate the chip by sending a cartesian voltage vector and a phase angle thus relieving the processor trom the task of output transformation from field into stator coordinates.

	NEW PRECALCULATING CURRENT CONTROLLER FOR DC DRIVES By Reimund Leonhard; Dierk Schroeder	[View] [Download]
Abstract: With respect fo the variing nonlinearity of a line commutated inverter the precalculating algorithm for a dc motor current control has been developed and implemented. Possible real time firing instants alpha(n) are on line examined ahead of real time to obtain a corresponding future mean value Id(n). Comparing this future current mean value Id(n) to the desired set point ld ref, firing instants may be derived exactly. Id(n) will result from future current shape id(T ,n), which is calculated in the signalprocessor using on line numerical integration of the armature differential equation. Repetetive use of the above precalculation of Id**(n) will yield a real time current controller with ideal step response no matter if the converter is operared in continuous or discontinuous mode.

	POWER CONDITIONNING AND CONCEPTUAL DESIGN OF PHOTOVOLTAIC HYBRID SYSTEMS By Noureddine Ben Slama; Mohamed Annabi; J. P. Requier	[View] [Download]
Abstract: This paper presents a general study of the photovoltaïc hybrid systems composed of multigenerators multireceptors and battery storage unit. In order to increase the reliability and the efficiency of their functionning, the energetic resources must be managed in real time. However, this brings about certain problems that we are trying to solve. We present the optimum power conditionning of both the photovoltaïc array and the wind generator and we analyse the transcient study of the system in order to guarantee minimal phase responses of the state variables. A typical hybrid installation was chosen and the main technical choises were discussed in purpose to illustrate the designing of such a system.