A study of the modified Kramer or asynchronous — Synchronous cascade variable-speed drive

  title={A study of the modified Kramer or asynchronous — Synchronous cascade variable-speed drive},
  author={M. Liwschitz and L. Kilgore},
  journal={Electrical Engineering},
LARGE wind tunnels require a wide range of speed and accurate speed control and if their use factor is high, a high efficiency over the working range is desirable. Also minimum disturbance to the power system is important in many cases. To meet these requirements a speed-control system has been adopted which, while not new in principle, involved the solution of a number of interesting problems. The system as shown in Figure 1 consists of a wound-rotor driving motor (A) whose secondary winding… 
A Static Variable-Frequency Three-Phase Source Using the Cycloconverter Principle for the Speed Control of an Induction Motor
This paper describes a variable-frequency source employing the cycloconverter principle. SCR's have been used as the principal switching and voltage-regulating devices. The logic of the firing
The development of variable-speed high-power drives for large wind tunnels
The paper outlines the power requirements of large wind tunnels, with particular reference to the compressor driving plant for high-speed and multi-purpose tunnels. After briefly reviewing available
Transients in a Kramer Cascade
This paper discusses some transients in a modified Kramer-cascade, i.e., a cascade with the mechanical converter replaced by a diode rectifier bridge. First, a new method of starting the drive is
Generation of Wind Power using Doubly Fed Induction Generator
Due to independent controlling mechanism for the active and reactive power, doubly fed induction generator (DFIG) is still culled by the wind turbine companies. The control strategies are
A StaticVariable-FrequencyThree-Phase Source Using theCycloconverter PrinciplefortheSpeed Controlof anInduction Motor
source employing thecycloconverter principle. SCR'shavebeenusedas theprincipal switching andvoltage-regulating devices. Thelogic of thefiring circuit hasbeendiscussed. Thefactor affecting output
Analysis and Control Aspects of Brushless Induction Machines with Rotating Power Electronic Converters
This thesis deals with the steady-state, dynamic and control aspects of new type of brushless configuration of a doubly-fed induction machine in which the slip rings and carbon brushes are replaced


The doubly fed machine
SYNCHRONOUS machines, operating with a-c excitation on both stator and rotor are used in many applications, for example, as induction frequency converters, as power and instrument Selsyn drives, and
Damping and Synchronizing Torque of the Double-Fed Asynchronous Machine
  • M. Liwschitz
  • Engineering
    Transactions of the American Institute of Electrical Engineers
  • 1941
I. Introduction THE double-fed asynchronous machine has become important in recent times as fan drive with wide speed range. The system consists of five main machines and the fan (see figure 1). It
Positive and negative damping in synchronous machines
The straight mathematical analysis of the damping problem on the synchronous machine leads to very complicated results. From these results, the conception of the phenomena occurring in the machine is
Variable-Speed Drive for United States Army Air Corps Wind Tunnel at Wright Field, Dayton, Ohio
THE machinery manufacturers are being required to solve many design and production problems in connection with our national-defense program. All electrical manufacturing companies are exerting