Optimal cut-off method and device for DC external transmission system of rich power in regional power grid

Abstract

The present invention provides an optimized cut-off method and device for a rich power DC external transmission system in a regional power grid. The method includes: obtaining the total number of units that need to be cut off in the regional power grid after a DC blocking fault; For wind turbines whose busbar transient voltage change is greater than or equal to the high-voltage withstand capacity, calculate the capacity of regional power grid units required by the safety control system and the total number of units that need to be cut off in the provincial power grid; cut off the provincial power grid according to the cut-off order of the provincial power grid . The present invention provides an optimized cut-off method and device for a rich power DC external transmission system of a regional power grid, which has strong operability and can be used to formulate safety control measures for actual UHV / HVDC power transmission systems and guide UHV / HVDC The reliable operation of the transmission system and the safe and stable operation of the AC-DC hybrid power grid after the UHV / HVDC transmission system is put into operation are of great practical significance.

Description

technical field [0001] The invention relates to the technical field of power system operation and control, in particular to an optimized cut-off method and device for a rich power DC external transmission system of a regional power grid. Background technique [0002] With the implementation of the air pollution prevention and control action plan and the gradual advancement of the country's vigorous development of new energy and the "West-to-East Power Transmission" energy strategy, new energy power generation technologies represented by wind power continue to develop, and long-distance, large-capacity cross-regional UHV DC projects have been put into operation one after another. At present, China is in a period of gradual adjustment of the energy structure, and limited by the pressure of ecological and environmental protection, the energy approval of thermal power units is relatively strict, and its construction and commissioning are relatively lagging behind, resulting in t...

AI Technical Summary

Problems solved by technology

After the safety control cut-off, due to the large-scale retreat of the power flow, the bus voltage of the substation near the DC converter station increases, which may exceed the upper limit of the normal operating voltage of the equipment and damage the electrical equipment; Causes overload of weak sections in the regional power grid, and even causes risks such as voltage instability in local areas

Therefore, how to select the cut-off position after the DC blocking fault, so as to ensure the stability of the regional power grid frequency, and at the same time reduce the section overload caused by the large-scale power fluctuation caused by the cut-off, the voltage instability in some areas, and the DC converter station. A series of secondary problems such as steady-state overvoltage in the near area have great practical significance for the formulation of safety control measures, guidance for UHV / HVDC transmission systems, and stable operation of interconnected grids after they are put into operation. Related research on this issue

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