My master's degree work is connected with investigation of the processes which arise when starting up turbogenerators to work in tandem with powerful network and processes arising while desynchronizing.
In [1] to determine the conditions how to recover the synchronous functioning of a generator the generalised curves of limiting phase traces are recommended. These curves are built for discrete values of the superfluous moment. The need to use multitude curves complicates their use. Besides, these curves do not take into account the influences of dampering moment upon the generator rotor movement.
In [2] it is noted that because of difficulty and absence of visuality of real processes of the generator start up, there exists the possibility to transform in to the condition of "hovering". In [2] the mathematical model of the generator start up to work in tandem with powerful network was designed. In mathematical model of a generator the rotor is taken into account only by one damper loop on axises of the symmetries of the rotor and there isn't any estimation how the system of excitement regulation influences upon the process generator start up. Automatic of control system of the synchronous machines excitement has main channels of regulation and channels of stabilisation. Automatіc Voltage Regulators (AVR) containing the main channels of the regulation are used abroad. The Channels of stabilisations are included in to a device named Power System Stabіlіzer (PSS).
In this work the further development of mathematical model for studying of the generator start up while working together with energy system is done. The Model includes the model of the generator in the form of full Parka - Gorieva equations and in the form of the changing schemes with multitude damper loops with constant parameters; the work also contains the equations, which describe the automatic control system of excitation of the strong action, AVR and PSS.
In models the generalised criterion [2] for estimation of the resource of using of the variable current machines while switching parallel work are used. The criterion is an integral from the module of the electromagnetic moment in terms of time of the transient process:
In [2] the formula is also given to determine the total dynamic action in elements of the generator under simultaneous action of synchronizing factor:
To determine the conditions how to recover synchronous functioning of the generator under non - synchronous repeated starts up the analytical expressions are used to determine the limiting curves of phase traces depending on the power of the previously set mode.
The Correlations allow to exclude the building of number of generalised limiting curves of phase traces for discrete values of the superfluous moments.
200 and 300 МW power generators were used for our investigation.
LITERATURE
1. Хачатуров А.А. Несинхронные включения и ресинхронизация в энергосистемах. – М.: Энергия, 1969. – 216 с.
2. Углов А.В. Управление включением синхронного генератора на параллельную работу с мощной сетью.: Автореф. дис….канд. техн. наук. -–Киев, 2006. – 20 с.