Method and device for phase loss protection of injection transformer line

Abstract

The invention relates to the field of relay protection of a power system, in particular to a method and a device for phase loss protection of an injection transformer line. The device comprises a control module, an injection power unit and a measuring unit, wherein the injection power unit is used for injecting current into the neutral point of the transformer, the input end of the control moduleis connected to the measuring unit, and the measuring unit comprises a zero-sequence current detecting module and a zero-sequence voltage detecting module for accessing the neutral point of the transformer to collect the zero-sequence current and the zero-sequence voltage of the neutral point; the control module determines whether the transformer line is out of phase by the data change of the zero-sequence current and / or the zero-sequence impedance, and the trip action and / or alarm information is output if the transformer line is out of phase to reliably detect and control the phase loss faultof the transformer under light load or no load condition, thereby solving the problem of damages to the power plant equipment caused by the failure of timely protection due to difficult transformer phase loss fault detection under light load or no load condition.

Description

technical field [0001] The invention relates to the field of relay protection of power systems, in particular to a method and device for phase loss protection of injection transformer lines. Background technique [0002] Auxiliary transformer line phase loss detection is one of the most concerned issues in nuclear power plants. Actual events in some nuclear power plants show that the phase loss on the high voltage side of the transformer may be difficult to be detected by existing equipment, instruments and electrical protection; if it is not timely If a phase loss condition is found and the transformer cannot be isolated from the system, it may lead to tripping of key motor-driven loads and loss of the safety system of the power plant; for example, the imbalance of the low-voltage side caused by the loss of phase of the auxiliary transformer of a nuclear power plant will first cause the voltage imbalance of the standby bus, and secondly It will cause tripping or failure to ...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a method and device for phase loss protection of injection transformer lines to solve the problem of power plant equipment damage caused by untimely protection caused by difficult detection of transformer phase loss faults under light load or no-load conditions

[0005] In order to achieve the above purpose, to reliably detect transformer phase loss faults under light load or no-load conditions, and to solve the problem of power plant equipment damage caused by untimely protection caused by difficult detection of transformer phase loss faults under light load or no-load conditions, the present invention An injection type transformer circuit phase loss protection device is provided, the protection device includes a control module, an injection power supply unit and a measurement unit; the injection power supply unit is used to inject current into the transformer neutral point, and the input terminal of the control module is connected to the The measurement unit, the measurement unit includes a zero-sequence current detection module and a zero-sequence voltage detection module for connecting to the neutral point of the transformer, so as to collect the neutral point zero-sequence current and zero-sequence voltage; the control module according to the zero-sequence Current and / or zero-sequence impedance judge whether the transformer line is out of phase, if the transformer line is out of phase, output trip action and / or alarm information

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