Method for suppressing sub-synchronous oscillation of wind power transmission system through series compensation by superconducting magnetic energy storage and control system for suppressing sub-synchronous oscillation of wind power transmission system through series compensation by superconducting magnetic energy storage

Abstract

The invention discloses a method for suppressing sub-synchronous oscillation of a wind power transmission system through series compensation by a superconducting magnetic energy storage and a controlsystem for suppressing sub-synchronous oscillation of a wind power transmission system through series compensation by a superconducting magnetic energy storage. The method comprises the steps of: thestep A, monitoring a bus power condition at the exit of a wind power plant in real time; the step B, if the control system determines the generation of sub-synchronous oscillation, starting an activeouter ring additional damping controller of a superconducting magnetic energy storage controller; the step C, observing the change state of the sub-synchronous oscillation, and if the convergence rateof the sub-synchronous oscillation does not reach a preset standard, starting a reactive outer ring additional damping controller of the superconducting magnetic energy storage controller; and the step D, when a sub-synchronous component of the power of the wind power plant in the system is smaller than an assigned value, quitting the outer ring additional damping controllers of the superconducting magnetic energy storage controller. Based on the sub-synchronous oscillation suppression method and the control system, on the basic function of the superconducting magnetic energy storage, the flexible and changeable operation conditions of the wind power plant can be adapted so as to effectively suppress the sub-synchronous oscillation of the wind power plant.

Description

technical field [0001] The present invention relates to the field of power system control, more specifically, to the technical field of new energy wind power control. Background technique [0002] In recent years, my country's wind power industry has developed rapidly. Affected by geographical conditions, wind power is mainly installed in the three northern regions, which are far from the load centers in the east and central regions. Series capacitor compensation technology is an important means to realize long-distance wind power transmission. Existing studies have shown that when the double-fed asynchronous wind turbine is sent out through series compensation, there is a risk of subsynchronous oscillation, which will have an adverse effect on the safe and stable operation of the wind farm. In 2009, a sub-synchronous oscillation occurred in a doubly-fed wind farm in Texas, USA, which caused a large number of units to trip and the crowbar circuit to be damaged. In 2012, a ...

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Problems solved by technology

Existing studies have shown that when the doubly-fed asynchronous wind turbine is sent out through series compensation, there is a risk of subsynchronous oscillation, which will adversely affect the safe and stable operation of the wind farm

In 2009, a synchronous oscillation occurred in a doubly-fed wind farm in Texas, USA, causing a large number of units to trip and damage the crowbar circuit

In 2012, subsynchronous oscillation occurred in a DFIG wind farm in northern Hebei, causing a large number of wind turbines to go off-grid

The additional damping control of wind turbines achieves the suppression effect by adding an additional command value of sub-synchronous frequency to the stator-side converter or rotor-side converter of the doubly-fed asynchronous fan, but this method is difficult to apply to the doubly-fed wind farm

The additional FACTS device is represented by parallel STATCOM, but the wind farm is sensitive to grid-connected voltage changes, and there is a risk of low-voltage and high-voltage off-grid. When the additional control of STATCOM has a great impact on the grid-connected point voltage, it is not conducive to the stable operation of the wind farm. And the STATCOM with constant voltage control has the risk of causing SSCI

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