Main circuit and method for improving voltage-source transverter DC power-transmission fault ride-through capability

Abstract

The invention discloses a main circuit and method for improving a voltage-source transverter DC power-transmission fault ride-through capability. A receiving-end convertor station and a sending-end convertor station are arranged between an AC receiving-end power grid and a wind power plant. A DC side of the receiving-end convertor station is connected with an energy-absorption device. A DC energy-absorption circuit at the DC wire inlet side of the receiving-end convertor station is configured into a type of spark gaps and metal-oxide voltage limiters. When a fault occurs to the AC side of the receiving-end power grid, the energy-absorption circuit triggers the spark gaps to act and then the gaps are switched on and DC voltages are applied to the two ends of the metal-oxide voltage limiters and the DC voltages are larger than the rated DC voltage of the metal-oxide voltage limiters. After the metal-oxide voltage limiters act, voltages are applied to the two ends of gap spark discharging devices and the metal-oxide voltage limiters and at the same time, the gap spark discharging devices control discharging current to be within a reasonable range. The new main-circuit structure adopts mature device elements such as the metal-oxide voltage limiters, the GAPs and the gap spark discharging devices and the like and operation reliability is high and cost of the DC energy-absorption circuit is reduced.

Description

technical field [0001] The invention relates to a main loop and a method for improving the DC transmission fault ride-through capability of a voltage source converter, and belongs to the innovative technology of the primary loop and the method for improving the DC transmission fault ride-through capability of the voltage source converter. Background technique [0002] In order to achieve sustainable development, using renewable energy such as solar energy and wind energy to generate electricity has become the development direction of the future power system. These power generation methods have the characteristics of being far away from the main grid and fluctuating greatly over time. The voltage source converter HVDC (VSC-HVDC) based on the voltage source converter can independently and quickly control the transmitted active power and reactive power. Active power and reactive power, with superior controllability and flexibility, have become the most potential power transmis...

AI Technical Summary

Problems solved by technology

The high-voltage IGBT series switch with this structure is technically difficult to realize, and a large number of high-power switching devices are used, and the cost is very high

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