A long-distance cable transmission and distribution network voltage control system

Abstract

The invention discloses a long-distance cable power transmission and distribution network voltage control system. The long-distance cable power transmission and distribution network voltage control system comprises a current transformer, an adjustable reactor, a SVG converter and a detection control assembly, wherein the current transformer is used for converting high voltage-side current into standard secondary current, the adjustable reactor is connected in parallel with loads on the same bus-bar through a first switch assembly and is used for performing stepless inductive reactive power adjustment according to an instruction of the control system when a circuit in a low-load state, the SVG converter is connected in parallel with the loads on the same bus-bar through a second switch assembly and is used for emitting inductive or capacitive reactive power according to an instruction provided by the detection control assembly, and the detection control assembly is used for detecting parameter information of a power grid, the adjustable reactor and the SVG converter, and automatically controlling the operation of equipment through real-time processing on the parameter information. The long-distance cable power transmission and distribution network voltage control system of the invention has the advantages of simple structure, reliable operation, high automation degree and the like.

Description

technical field [0001] The invention mainly relates to the field of power transmission and distribution of power grids, in particular to a voltage control system suitable for long-distance cable transmission and distribution networks. Background technique [0002] At present, a large number of cables are used in the power transmission and distribution lines of the power grid. Under the action of AC voltage, the cable line conducts capacitive reactive charging to the grid. The higher the voltage level, the larger the cable section and the longer the line, the greater the reactive charging power. This capacitive reactive power not only increases the node voltage at both ends of the cable line, but also affects the voltage level of other nodes because the reactive power flows in the grid. [0003] When the load is low, the overall voltage of the grid is high. At this time, the reactive charging power of the cable line will further increase the voltage level of the grid. In sev...

AI Technical Summary

Problems solved by technology

When the load is low, this method can better suppress the voltage rise of the grid, but when the load of the line is high, the load consumes a large amount of reactive power, which will seriously reduce the voltage of the line, because the total capacity of the shunt reactor remains unchanged , even if the reactor is out of operation, the grid voltage will still be lower than the normal level

The capacitive reactive power of the long-distance cable transmission and distribution network is generally large at light load, and the reactive power that needs to be compensated at overload is relatively small. If SVG is simply used for regulation, the technical difficulty is very high, and the equipment cost will be high , the number of IGBT modules is large, and failures are prone to occur. In addition, the actual output is small when overloaded, resulting in waste of capacity

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