Fault ride-through control method and device of new energy island flexible direct transmission system

Abstract

The invention provides a method and a device for realizing new energy fault ride-through control under the coordination control of an energy storage device and a flexible DC converter station. For theflexible grid with the island access to new energy, when the DC power grid fails, the transmission power is limited, signals on an AC bus (voltage change, frequency change, etc.) are controlled by the predetermined DC converter station, the energy storage device is subjected to fast active power control to reduce the impact of island access to the new energy power station to ensure that the DC converter station is not overloaded, then, according to the given power transmission capacity of the DC power grid after the fault is restored, a power control system of a new energy power station and the energy storage device are started to perform power control to achieve a balance with the capacity of the converter station, and fault ride-through is achieved. The method is advantaged in that theimpact of island access to the new energy power station can be reduced through rapid active power adjustment, moreover, the control system of the converter station of the DC power grid is further veryflexible, and coordinated adjustment of the two can effectively reduce the effect of the fault.

Description

technical field [0001] The present invention relates to the technical field of electric power system control, and more specifically, relates to a fault ride-through control method of a new energy island flexible direct transmission system based on the coordination of a flexible DC converter station and an energy storage device. Background technique [0002] China's energy resources and energy consumption are very unbalanced. Energy-rich areas are far away from economically developed areas. The geographical distribution of primary energy presents a pattern of more west and less east. Most of my country's new energy is concentrated in the three north regions of northeast, north and northwest. And the load center is in the southeast coast of Zhejiang and Jiangsu, and a large amount of enriched new energy needs to be sent out. Take Jiuquan 10 million-kilowatt wind power base in Gansu Province as an example. The base is more than 800-3,000 kilometers away from the central and east...

AI Technical Summary

Problems solved by technology

[0005] Large-scale new energy is connected to the flexible DC power grid in an island manner. It is difficult for new energy units to sense the occurrence of a fault in the flexible DC power grid in a timely manner, and they still generate power according to normal conditions, which will lead to overload blocking of the DC converter station

In addition, the current protection of the flexible straight grid is at the ms level, and it is difficult for new energy units to achieve emergency control of power within the ms level

Images