Control Winding Current Research Articles

Parameter Design and Static Performance of Dual Stator-Winding Induction Generator Variable Frequency AC Generating System With Inductive and Capacitive Loads

In this paper, the design methods of the auxiliary excitation capacitors and the filter inductances are investigated for the dual stator-winding induction generator (DWIG) variable frequency ac (VFAC) generating system with inductive and capacitive loads, and the system static performance is presented as well. For this generating system, the proper selection of the auxiliary excitation capacitors and the filter inductances can minimize the reactive power capacity of the control winding, reduce the capacity of the static excitation converter (SEC) and improve the system static performance of the output voltage. The corresponding design principles and methods are proposed based on the change law of the control-winding reactive power and the requirements of the control-winding current. The experimental results show that the proposed design methods are correct and valid, and the DWIG VFAC generating system has a good static performance with the minimum-capacity control-winding reactive power and a compact-size SEC.

Robust Current and Torque Controls for PMSM Driven Satellite Reaction Wheel

This paper presents the robust current and torque controls for a satellite reaction wheel system driven by permanent magnet synchronous motor (PMSM) is presented. First, the motor nominal key parameters are estimated, and the digital signal processing (DSP)-based PMSM driven reaction wheel system using intelligent power module is established. In the proposed robust current controlled pulsewidth modulated (PWM) scheme, the feedback controller is augmented with a command feedforward controller and a simple observed disturbance robust cancellation controller. Theoretic bases and design procedures of all constituted controllers are derived in detail. The proposed control scheme is very effective in handling sinusoidal PMSM varying-frequency winding current tracking control under sinusoidal back electromotive force (EMF) disturbance. Very close and robust PMSM winding current tracking performance under varying system parameters and operating conditions can be obtained. With excellent winding current control characteristics, the robust torque control of the PMSM driven reaction wheel is then performed to yield quick observed torque control response. The driving performance of the developed reaction wheel is evaluated experimentally, the improved torque generating capability and energy conversion efficiency are confirmed from some measured results.

Direct torque control of synchronous motor drives for dynamically demanding applications

This paper proposes a new concept for the Direct-Torque-Control (DTC)-based synchronous machine drive. DTC technology provides a synchronous machine drive with excellent dynamic properties. The DTC principles are first briefly recalled. The study observes the problem of the flux linkage integration instability and introduces the flux linkage estimate correction method based on the current model. The field winding current control methods are analysed. It is shown that a synchronous machine drive also needs a stabilisation method when working with very high load angles especially in the field weakening range. A method to control the load angle directly is then proposed. Test results with a 14.5-kVA laboratory prototype drive are given.

On the feedback in magnetic amplifiers: II - Combined magnetic and electric feedbacks

A previous paper1 has presented a steady-state and transient analysis of various types of feedback, magnetic or electric, applied to a self-saturating bridge or center-tap amplifier. This paper is a brief extension of that treatment to certain combinations of a positive magnetic feedback and a negative electric feedback as used by Geyger in ?voltage-balance? and ?current-balance? potentiometer-type amplifier circuits.2?4 The essential principle of these feedback combinations is well-known: The positive magnetic feedback reduces the control winding current, while the negative electric feedback insures stability and linearity without modifying the current requirements of the control winding. Two examples are shown in the schematics of Appendixes I and II. (The symbols and terminology are those used consistently in reference 1 and shall not be restated in detail.)