EPE Association: EPE 1989 - 16 - Lecture Session 2.9: ADJUSTABLE SPEED DRIVES

EPE 1989 - 16 - Lecture Session 2.9: ADJUSTABLE SPEED DRIVES
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1989 - Conference > EPE 1989 - 16 - Lecture Session 2.9: ADJUSTABLE SPEED DRIVES

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   MODELLING THE INVERTER-FED INDUCTION MACHINE
By R. Tanner; K. Reichert [View]
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Abstract: This paper introduces a new transient model of the induction machine with squirrel-cage rotor considering eddy currents in the rotor bars and space-harmonics in the airgap-field due to the slotted windings. The eddy currents are taken into account by separating the rotor bars into different conductors, which allows arbitrary shapes of rotor bars to be simulated. Rules are indicated to reduce the number of necessary equations. A comparison between the traditional basic model and the one proposed in this paper is made by means of the ohmic losses of an induction machine fed from a voltage-source inverter.

   MODELLING AND IDENTIFICATION OF A SIX-PHASE CONVERTER FED SYNCHRONOUS MACHINE
By H. Bissig; W. Vetter; K. Reichert [View]
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Abstract: A synchronous machine with two three phase armature winding systems, fed by two converters, is investigated by simulations and measurements. In order to analyse the commutation and the additional losses, produced in the rotor by the harmonics of the armature currents, a model is derived, that regards the coupling of the two armature systems and represents the rotor in a wide frequency range correctly. With standstill response tests the model is identified for a 4MVA synchronous machine with solid iron rotor and complete damper winding. For the given machine numerical calculations are made and compared with results obtained experimentally.

   AC-MOTOR DRIVE WITH REGENERATIVE BRAKING AND REDUCED SUPPLY LINE DISTORTION
By O. Niermeyer; D. Schröder [View]
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Abstract: A standard squirrel-cage induction motor is connected to a pulse-width-modulated inverter supplied by a constant dc-link voltage. The dc-link is fed by a similar inverter from the three phase line, allowing power flow between the line and the machine in arbitrary direction at zero phase displacement and low line current harmonics. Each inverter is controlled by a current vector control with on-line optimization to minimize the inverter losses for a predefined current hysteresis. The line current phase displacement and the dc-link voltage are controlled by the superimposed lineside control. The machine state control, based on flux orientation for impressed stator currents uses a machine model to estimate the non-measurable internal machine values. Correlating signals obtained in the current control with model signals enables fast readjustment of the model parameters according to the variable machine parameters. High utilisation of all power components and a distinguished dynamic behaviour are the essential advantages of the presented Four-Quadrant AC-Motor Drive with full digital control.

   CONTROL OF INPUT REACTIVE POWER FOR CONVERTER-FED SYNCHRONOUS MACHINES
By F. W. Fuchs; C. Schulze Dieckhoff [View]
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Abstract: Present state of the control technique for converter-fed synchronous machines with machine-commutated inverter is the constant margine angle control. With this method, the motor and input reactive power is minimized. More than that, with additional .equipment, control of the input reactive power is possible. The manipulated variable is the extinction angle of the motor-side inverter. Adding a mains displacement meter and controller to the basic control system, a closed loop input reactive power control is achieved. Reactive power can thus be controlled over a certain range, limited by the system properties. This reactive power control lends itself particularly well to special applications, i.e. load torque varying with the square of the speed. It provides together with a low step switched reactive power compensator, a constant input reactive power. The concept, calculations and measurements of an industrial, microprocessor-controlled drive system of this kind are represented.

EPE 1989 - 16 - Lecture Session 2.9: ADJUSTABLE SPEED DRIVES
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1989 - Conference > EPE 1989 - 16 - Lecture Session 2.9: ADJUSTABLE SPEED DRIVES
	[return to parent folder]

	MODELLING THE INVERTER-FED INDUCTION MACHINE By R. Tanner; K. Reichert	[View] [Download]
Abstract: This paper introduces a new transient model of the induction machine with squirrel-cage rotor considering eddy currents in the rotor bars and space-harmonics in the airgap-field due to the slotted windings. The eddy currents are taken into account by separating the rotor bars into different conductors, which allows arbitrary shapes of rotor bars to be simulated. Rules are indicated to reduce the number of necessary equations. A comparison between the traditional basic model and the one proposed in this paper is made by means of the ohmic losses of an induction machine fed from a voltage-source inverter.

	MODELLING AND IDENTIFICATION OF A SIX-PHASE CONVERTER FED SYNCHRONOUS MACHINE By H. Bissig; W. Vetter; K. Reichert	[View] [Download]
Abstract: A synchronous machine with two three phase armature winding systems, fed by two converters, is investigated by simulations and measurements. In order to analyse the commutation and the additional losses, produced in the rotor by the harmonics of the armature currents, a model is derived, that regards the coupling of the two armature systems and represents the rotor in a wide frequency range correctly. With standstill response tests the model is identified for a 4MVA synchronous machine with solid iron rotor and complete damper winding. For the given machine numerical calculations are made and compared with results obtained experimentally.

	AC-MOTOR DRIVE WITH REGENERATIVE BRAKING AND REDUCED SUPPLY LINE DISTORTION By O. Niermeyer; D. Schröder	[View] [Download]
Abstract: A standard squirrel-cage induction motor is connected to a pulse-width-modulated inverter supplied by a constant dc-link voltage. The dc-link is fed by a similar inverter from the three phase line, allowing power flow between the line and the machine in arbitrary direction at zero phase displacement and low line current harmonics. Each inverter is controlled by a current vector control with on-line optimization to minimize the inverter losses for a predefined current hysteresis. The line current phase displacement and the dc-link voltage are controlled by the superimposed lineside control. The machine state control, based on flux orientation for impressed stator currents uses a machine model to estimate the non-measurable internal machine values. Correlating signals obtained in the current control with model signals enables fast readjustment of the model parameters according to the variable machine parameters. High utilisation of all power components and a distinguished dynamic behaviour are the essential advantages of the presented Four-Quadrant AC-Motor Drive with full digital control.

	CONTROL OF INPUT REACTIVE POWER FOR CONVERTER-FED SYNCHRONOUS MACHINES By F. W. Fuchs; C. Schulze Dieckhoff	[View] [Download]
Abstract: Present state of the control technique for converter-fed synchronous machines with machine-commutated inverter is the constant margine angle control. With this method, the motor and input reactive power is minimized. More than that, with additional .equipment, control of the input reactive power is possible. The manipulated variable is the extinction angle of the motor-side inverter. Adding a mains displacement meter and controller to the basic control system, a closed loop input reactive power control is achieved. Reactive power can thus be controlled over a certain range, limited by the system properties. This reactive power control lends itself particularly well to special applications, i.e. load torque varying with the square of the speed. It provides together with a low step switched reactive power compensator, a constant input reactive power. The concept, calculations and measurements of an industrial, microprocessor-controlled drive system of this kind are represented.