Paper Title
Fed-Converted Generator Based on the Squirrel-Cage Rotor Asynchronous Machine, With Condensing Self-Excitation and Stabilization of the Output Voltage
Abstract
Based on the traditional model description of a three-phase asynchronous machine with a squirrel-cage rotor (AMSCR) for the generator mode of its operation on the rectifier load, its computer simulation model is formed and, the capacitance of self-excitation capacitors block (SECB) for this specific type of machine are determined depending on the rotational shaft speed of AMSCR and the load current. On this basis, a computer simulation of the relevant modes of operation of the AMSCR was carried out, including the process of its launch and the stabilization of the output voltage. The researched electro-technical complex (ETC) belongs to the class of machine-electronic generating systems with stabilized DC voltage named MEGS-1. To stabilize the rectified voltage of MEGS-1 uses a discrete change in the capacitance of self-excitation capacitors block. In order to simplify this block by reducing the number of capacitors during its structural-algorithmic synthesis, the principle of pulse-code modulation is applied. A method for accelerated start-up of the AMSCR, which reduces the time of its launch, is proposed. It is shown that the operation of three-phase AMSCR with SECB for a rectifier load (based on a bridge rectifier circuit diagram) is characterized by the presence of 5th (more than 50%) and 7th (about 20%) harmonics (in% from the fundamental harmonics) in the voltages and currents of the armature windings. The article material can be used as a methodological basis for system design of ETC of this class.
Keywords - Asynchronous Machine with a Squirrel-Cage Rotor, Generator Mode, Self-Excitation Capacitor, Rectifier Load, Variable Load and Shaft Speed, Voltage Stabilization, Discretely Switched Capacitors, Pulse-Code Modulation.