Abstract:The scale of offshore wind power is expanding, and the power needed to transmit to land is also increasing rapidly. Affected by the cost and the channel, the submarine cable can not be laid on a large scale. It is an important way to enhance the transmission capacity of the submarine cable by reactive power compensation. In this paper, the influence of reactive power on the maximum transmission capacity near the wind farm of the submarine cable is analyzed. When the reactive power of the middle point of the submarine cable is minimum, the voltage is highest, and the reactive power is evenly distributed among the terminals of the submarine cable line, the transmission capacity will be improved. On this basis, a simplified method for calculating the optimal shunt reactor capacity near the wind farm side of the submarine cable is proposed. When the power factor on the wind farm side is adjusted to a reasonable small negative value, it is helpful to consume part of the charging power of the submarine cable and reduce the investment cost of reactive compensation.