METHOD AND DEVICE FOR SUPPRESSING MAGNETIC FIELD OF EXCITATION WINDING OF SYNCHRONOUS MACHINE (VARIANTS) Russian patent published in 2006 - IPC H02H7/09 H02P9/14 

FIELD: electric engineering, namely engineering of excitation systems for synchronous machines, namely, devices for suppressing magnetic field of excitation winding of synchronous machines.

SUBSTANCE: method for suppressing magnetic field of synchronous machine is performed by measuring voltage on excitation winding, comparing it to setting, and each time when this voltage decreases to level of setting, resistance of resistor in passage contour of excitation current is increased by one step up to value equal to relation of voltage, maximally allowed in accordance to operation conditions of excitation winding isolation, to current value, at which voltage reached the setting. In accordance to first variant of device for realization of current method, resistor is divided on two similar portions, between which commutator is inserted, containing two oppositely included parallel thyristors, in parallel to which contactor is connected. In parallel to part of this circuit, consisting of serially connected commutator and resistor, the latter being connected to clamp of excitation winding, connected to positive pole of excitation device, a branch is connected, containing serially connected: resistor, connected to clamp of excitation winding, connected to positive pole of excitation device, and thyristor, cathode of which is connected to aforementioned resistor. At the same time in parallel to circuit, containing serially connected commutator and resistor, connected to clamp of excitation winding, which is in turn connected to negative pole of excitation device, a branch is connected, containing serially connected: thyristor, anode of which is connected to clamp of excitation winding, connected to negative pole of excitation device, and another resistor, in parallel to which a capacitor is installed. Clamp of excitation voltage indicator is connected to first input of logic block. Circuits for controlling thyristors, anodes of which are connected to resistor, connected to clamp of excitation winding, connected to negative pole of excitation device, are combined and connected to first output of logic block. At the same time, circuit for controlling thyristor of field suppression device, connected by cathode to resistor, connected to clamp of excitation winding, connected to negative pole of excitation device, is connected to second output of logic block. Block-contacts of automatic switch are connected to another input of logic block. Third output of logic block is connected to circuit for controlling thyristor of field suppression device, connected by anode to output of excitation winding, connected in turn to negative pole of excitation device. In accordance to second variant of device for realization of current method, for decreasing machine field suppression time, resistor is divided on "n" similar sections, while commutator is installed between first and second parts of resistor, counting from clamp of excitation winding, connected to positive pole of excitation device. Branch, which contains serially connected thyristor and resistor, in parallel to which capacitor is connected, by anode of thyristor is connected to connection point of second and third parts of resistor, counting from clamp of excitation winding, connected to positive pole of excitation device. By clamp of resistor the aforementioned branch is connected to clamp of first part of resistor, connected simultaneously to commutator and to output of excitation winding, connected to positive pole of excitation device. Similar following branches are connected in parallel to each section of circuit, containing resistor and thyristor of previous similar branch, which by anode is connected to connection point of current and previous resistor. By contact of resistor such a branch is connected to cathode of thyristor of previous similar branch.

EFFECT: decreased suppression time of synchronous machine field while maintaining simplicity of device, meant for realization of proposed method for suppressing magnetic field of excitation winding of synchronous electric machine.

3 cl, 8 dwg