Self-Excitation System for Synchronous Generator

Abstract

-Self-excitation for synchronous generator is described in the paper. The system is based on a buck converter input filter capacitor discharge through excitation winding of the generator. The buck converter is connected to the stator outputs through an uncontrollable diode rectifier, but excitation winding is used as a load. Input filter capacitor of the converter provides initial current pulse which magnetizes excitation system and produces the generator voltage increase, for this reason the capacitor is charged before self-excitation process starts.Results of the computer simulation and physical experiment are obtained and presented. These results show that the proposed self-excitation converter in conjunction with an input capacitor pre-charged from a low-power electronic generator actually magnetizes the generator excitation system therefore generator voltage and accordingly excitation current increases. Stabilization of generator output voltage occurs with a voltage surge, though its peak value slightly exceeds the reference one.The future investigation of the proposed self-excitation system may include definition of mathematical equations which describe transients in the generator's self-excitation mode and development of control methods for purpose of self-excitation process control without voltage peaks. The computer model also should be improved.

The Effect of Loading on The Generator Voltage on The Pico-Hydro Power Plant: Experimental Study

“…First, the charged capacitor is released through the excitation roll L f . In the applied generator, the excitation winding parameters are L f = 17 mH and R f = 2 Ω [4]. Fig.…”

“…Fig. 1 The self-excitation system equivalent scheme [4] This stage depends on circuit parameters and capacitor initial voltage : (1) Where is capacity of capacitor .…”

“…The process is developing only if k >( ). Indicator k characterizes connection between the equivalent electromotive force of generator and current in excitation winding and it depends on the rotation speed of generator [4].…”

Improvement of self-excitation process in synchronous generator

“…One of the methods to improve the self-excitation process in synchronous generator [2,3,5] provides the use of the capacitor in an excitation circuit (Fig. 6).…”

“…In the case of the synchronous generator with independent excitation [1][2][3][4][5] it is necessary to provide selfexcitation process which depends on several factors.…”