Upfc series transformer charging startup debugging method

Abstract

The invention discloses a charging starting debugging method for a serial transformer of a unified power flow controller (UPFC). The method comprises: (1), a shunt transformer is used as a power supply to carry out a high-voltage side isolation state charging of a series transformer to determine an electromagnetic transient process and a TBS running state of series transformer charging, and voltage nuclear phase and series transformer wiring checking are completed by means of voltage transformer PT charging of a high-voltage side with line bus side of the series transformer and voltage transformer PT charging of a high-voltage side with line outlet side of the series transformer; (2), high-voltage side charging is carried out on the series transformer by a line switch and series transformer protection and load checking are carried out by using line closing-loop currents; (3), low-voltage side charging of the series transformer and high-voltage side charging temporary protection configuration are carried out. According to the invention, charging of a series transformer, a thyristor bypass switch (TBS), and correlated devices as well as nuclear phase and protection checking of the series transformer can be completed.

Description

technical field [0001] The invention relates to a charging start-up debugging method for a UPFC series transformer, belonging to the technical field of power system automation. Background technique [0002] The unified power flow controller (Unified Power Flow Controller, UPFC) is composed of a parallel side converter and a series side converter. The parallel side is enough to realize active and reactive power adjustment. Active power adjustment is mainly to stabilize the DC capacitor voltage and absorb active power from the grid. To compensate the active power required by the series side and its own active power consumption, reactive power regulation is to inject reactive power into the system to stabilize the voltage at the access point. The series side regulates the line power flow by controlling its series injection voltage vector. [0003] The UPFC system mainly consists of converters, DC connection lines, series transformers and parallel transformers. The parallel sid...

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Problems solved by technology

[0006] Due to the particularity of the connection mode of the series transformer in the UPFC system and the way of connecting to the system, the traditional charging start-up method for the transformer (connected to the power grid in parallel) is no longer applicable, mainly reflected in: 1) The low-voltage side of the series transformer is directly connected to the transformer 2) The windings on the high-voltage side of the series transformer are directly connected in series as in the line, and bypass switches are configured on the high-voltage and low-voltage sides. According to its connection mode and operating requirements, The series transformer cannot be connected in series with both the high and low voltage sides open, and the switching of the series transformer from the high voltage side cannot be realized.

In short, the converter valve on the UPFC series side is connected to the power grid through a series transformer. Due to the special connection mode and connection mode of the UPFC system series transformer, the traditional charging and starting debugging method for the transformer (parallel connection to the power grid) is no longer necessary. Applicable, it is not possible to directly conduct charging switching tests on series transformers at rated voltages

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