Fault ride-through control method of offshore wind power direct current collection and transmission system

Abstract

The invention discloses a fault ride-through control method for an offshore wind power direct-current collection and transmission system. The method comprises the following steps: configuring a centralized unloading circuit at a direct-current collection bus of an offshore wind power plant; obtaining a first direct current bus voltage of a wind turbine generator, a second bus voltage of a direct current collection system and a third direct current bus voltage of a flexible direct current power transmission system; subtracting the first direct-current bus voltage, the second direct-current busvoltage and the third direct-current bus voltage from the corresponding starting threshold values respectively, multiplying the obtained maximum output value by a proportionality coefficient through an amplitude limiting link, and generating a duty ratio through a pulse modulation link so as to control the centralized unloading circuit to consume energy; and when the first direct-current bus voltage, the second direct-current bus voltage and the third direct-current bus voltage are all recovered to be below the corresponding starting threshold values, making the centralized unloading circuit quit operation, and recovering the system to normal. According to the invention, fault ride-through of an onshore AC system can be realized, and fault ride-through of a DC power transmission system canalso be realized.

Description

technical field [0001] The invention relates to the technical field of offshore wind power operation control, in particular to a fault ride-through control method for an offshore wind power direct current collection and transmission system. Background technique [0002] With the continuous and rapid development of my country's economy, the contradiction between environmental protection and economic development has become increasingly prominent. The low-carbon economy based on energy conservation and emission reduction has become a strategic measure to maintain sustainable social development. Offshore wind power has the characteristics of abundant resources, relatively high utilization hours of power generation, and relatively high-end technology. It is the frontier field of new energy development. [0003] The large-scale offshore wind power collection and transmission system is the key to realize grid-connected consumption of offshore wind power. When the large-scale offsh...

AI Technical Summary

Problems solved by technology

However, this solution is aimed at the transmission mode of "AC collection + DC transmission" of offshore wind power. If it is applied to the "DC collection + DC transmission" system, the overall number of unloading devices is large and the investment is large. Between multiple unloading devices There is also a lack of coordination and cooperation, resulting in low efficiency of fault ride-through control of offshore wind power collection and transmission systems

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