Control system of offshore wind power flexible DC power transmission current transformer

Abstract

The invention relates to a control system of a flexible wind power DC convertor on the sea, which pertains to the technical field of power transmission in wind power generation and comprises the doubly closed loop control structure of a sending end rectifier on the sea and the doubly closed loop control structure of a receiving end inverter on the coast; the doubly closed loop control structure of the sending end rectifier on the sea is used for controlling the active power of a flexible DC transmission system and the voltage stability of a wind power AC system; the doubly closed loop control structure of the receiving end inverter on the coast is used for controlling the constant voltage of the DC side of a receiving end convertor and the dynamic regulation of the reactive power of the main network accessing end of the receiving end convertor; two control structures are mutually independent and no data communication exists between the two control structures. The control system can fast and correctly control the active power of wind power transmission on the sea as well as promote the stability of the wind power AC system on the sea and the transmission efficiency and the power quality of the whole DC transmission system.

Description

technical field [0001] The present invention relates to a control system in the technical field of electric power transmission, in particular to a control system for an offshore wind power flexible direct current transmission converter. Background technique [0002] Offshore wind farms have the characteristics of high wind speed, low rate of change of wind speed with altitude, low wind turbulence, and high wind energy output. my country has abundant offshore wind energy resources. In recent years, the development and utilization of offshore wind energy has been widely and highly valued. Flexible DC transmission is a new type of power transmission technology based on voltage source converter (VSC), insulated gate bipolar transistor (IGBT) and pulse width modulation (PWM). It has the advantages of independent control of active power and reactive power of the transmission system, no need for additional reactive power compensation equipment, etc., and meets the requirements of ...

AI Technical Summary

Problems solved by technology

This kind of control system has the advantages of simple structure and quick response to changes in transmission power. Its disadvantages are mainly that it cannot accurately estimate the electrical power loss of the offshore wind farm and the power loss of the local load of the wind farm, and it is prone to power imbalance and high probability of failure. question

[0004] The search also found that Weixing Lu et al published on IEEE Power Engineering Review Optimal Acquisition and Aggregation of Offshore Wind Power by Multiterminal Voltage-Source HVDC Power Engineering Review, January 2003, No. 1), designed an indirect power control system, which indirectly adjusts the rectifier at the offshore sending end by observing the frequency of the AC system of the wind farm according to the power-frequency characteristics of the wind farm AC system Although it can effectively overcome the shortcoming of underestimating the power loss, this system belongs to the indirect power control system. When the wind speed of the wind farm changes, the dynamic response of the transmission power is slow, the transmission efficiency is low, and the control effect is not good. very ideal

Images