Topology design method and device of current collecting system of offshore wind farm

The invention provides a topology design method and a topology design device of a current collecting system of an offshore wind farm. The topology design method comprises the following steps of: generating topological structures meeting the constraint conditions according to input information of a user and various constraint conditions; carrying out load flow calculation on the generated topological structures, obtaining line current values on all the topological structures, and selecting the types of cables and switches of corresponding lines; calculating the economy cost of all the topological structures according to the investment cost and the maintenance cost of the cables and switches selected; calculating the reliability cost of all the topological structures according to the fault occurrence probability of the selected cables and switches; and carrying out sequencing on all the topological structures according to the economy cost and the reliability cost or simultaneous consideration of the comprehensive cost of the economy cost and the reliability cost, and selecting the topological structures with preset quantity for output. The topology design method and the topology design device have the advantages that automatic design of the topological structures of the current collecting system of the offshore wind farm is realized by a computer, so that the investment on labor, cost and time is greatly saved.