A method for protecting a synchronous machine against damage caused by pole slipping

Abstract

The subject of the invention is a method for protecting a synchronous machine (2) against damage caused by pole slipping, applicable during the operation of the synchronous machine in a power generating unit or a drive unit (1) in an electric power network. In the inventive method, measured signals of current and voltage of the synchronous machine (2) and assumed constant parameters are the basis for determining a binary logical indicator of the occurrence of a disturbance (Trig_start), for which the criterion of disturbance occurrence proves to be valid, which when fulfilled means that pole slipping can occur, then a binary logical indicator of pole slipping (PS_det) is determined, for which the criterion of occurrence of a pole slipping proves to be valid for the generator mode or the drive mode, which criterion when fulfilled, the time of rotor operation with the occurrence of pole slipping is totalized, a binary logical indicator of the decision about the trip action is determined (PS_trip), for which the criterion of exceeding a threshold value allowed for the rotor operation with slipping proves to be valid, which when fulfilled, automatically activates measures protecting the synchronous machine (2) against slipping. If, in the course of execution of the disturbance occurrence detection process, after a defined time, the disturbance occurrence criterion is not fulfilled, the process of sudden disturbance detection and / or the process of accrued disturbance detection is conducted, which processes are conducted until the criterion of pole slipping occurrence is fulfilled for the generator mode or for the motor mode, after which further actions are continued as previously.

Description

technical field [0001] The subject of the present invention is a method for protecting a synchronous machine from damage caused by magnetic pole slip, which method is applicable during operation of a synchronous machine in a generating unit or in a drive unit in a power network. The inventive method uses the detection of pole slip resulting from overloads and field losses in synchronous machines as well as pole slip caused by faults and voltage collapse. The inventive method is applicable in both synchronous motors and synchronous generators. Background technique [0002] Slipping of rotor poles in synchronous machines operating as part of a power generation or drive unit can occur due to delayed elimination of faults in the power grid or due to incorrect excitation of synchronous machines. Due to continuous pole slip, synchronous machines may lose synchronization with the power grid. During pole slip in the case of generator mode operation of a synchronous machine, oscill...

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Problems solved by technology

In the presented method, the detection of the slip phenomenon in a synchronous generator depends on the type of exciter used to excite the generator, and in synchronous generators (which contain excitation equipment other than that presented in the described method) case, it cannot be achieved

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