Quick distance protection method and apparatus for power transmission line containing UPFC

Abstract

The invention relates to a quick distance protection method and apparatus for a power transmission line containing an UPFC. The quick distance protection method and apparatus can effectively avoid the risk that misoperation occurs during the quick distance protection process by means of calculation of the maximum equivalent impedance of the UPFC during the normal operation process generally and by means of the calculated maximum equivalent impedance during the normal operation process when a system malfunctions and the fault compensation voltage is calculated; and at the same time the distance protection method and apparatus can also avoid the risk that a surpass motion exists in the quick distance protection process when the protection apparatus is used at the side being far away from the UPFC and when an outside-of-area metallic fault occurs in the positive direction.

Description

technical field

[0001] The invention belongs to the technical field of electric power system relay protection, and in particular relates to a fast-distance protection method for transmission lines containing UPFC. Background technique

[0002] The unified power flow controller (UPFC) can quickly and flexibly control the power flow of the line, improve the power flow distribution characteristics of the power grid, and maximize the transmission capacity of the power grid; it also has the ability to damp system oscillation and improve the stability of the power grid; Scale load shedding; optimize power flow distribution, reduce circulation, and reduce network loss. By injecting a voltage phasor with controllable phase angle and amplitude into the line, UPFC directly changes the potential characteristics of the head and end of the line, thereby further changing the potential phase and amplitude distribution in the system, and regulating the power flow distribution in the entire ...

Examples

Embodiment Construction

[0029] The present invention will be described in further detail below in conjunction with the accompanying drawings.

[0030] method embodiment

[0031] The fast-distance protection method for a transmission line containing UPFC in the method embodiment of the present invention is used in the protection of an AC transmission line containing UPFC system access. Transmission lines with UPFC systems such as figure 1 As shown, the fast distance protection workflow is as follows figure 2 As shown, the method includes the following steps:

[0032] (1) The line protection devices on both sides independently collect the voltage and current of each side;

[0033] The method of collecting voltage and current on both sides is as follows: for the near UPFC side, the voltage is measured by the line side PT, and the current is measured by the line CT; for the far UPFC side, the voltage can be measured by the line side PT or the bus side PT, and the current is measured by the line CT. ...

technical field

[0001] The invention belongs to the technical field of electric power system relay protection, and in particular relates to a fast-distance protection method for transmission lines containing UPFC. Background technique

[0002] The unified power flow controller (UPFC) can quickly and flexibly control the power flow of the line, improve the power flow distribution characteristics of the power grid, and maximize the transmission capacity of the power grid; it also has the ability to damp system oscillation and improve the stability of the power grid; Scale load shedding; optimize power flow distribution, reduce circulation, and reduce network loss. By injecting a voltage phasor with controllable phase angle and amplitude into the line, UPFC directly changes the potential characteristics of the head and end of the line, thereby further changing the potential phase and amplitude distribution in the system, and regulating the power flow distribution in the entire ...

Examples

Embodiment Construction

[0029] The present invention will be described in further detail below in conjunction with the accompanying drawings.

[0030] method embodiment

[0031] The fast-distance protection method for a transmission line containing UPFC in the method embodiment of the present invention is used in the protection of an AC transmission line containing UPFC system access. Transmission lines with UPFC systems such as figure 1 As shown, the fast distance protection workflow is as follows figure 2 As shown, the method includes the following steps:

[0032] (1) The line protection devices on both sides independently collect the voltage and current of each side;

[0033] The method of collecting voltage and current on both sides is as follows: for the near UPFC side, the voltage is measured by the line side PT, and the current is measured by the line CT; for the far UPFC side, the voltage can be measured by the line side PT or the bus side PT, and the current is measured by the line CT. ...

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