Additional damping control doubly-fed fan grid-connected sub-super-synchronous oscillation suppression method

Abstract

The invention discloses an additional damping control doubly-fed fan grid-connected sub-super-synchronous oscillation suppression method. For the sub-super-synchronous oscillation phenomenon caused bygrid connection of a doubly-fed fan through a series compensation power transmission line, a second-order low-resistance filter is added to a doubly-fed fan rotor side converter control link to suppress the generation of the sub-super-synchronous oscillation phenomenon. The method comprises the following steps: firstly, establishing a mathematical impedance model under a dq coordinate system of the doubly-fed fan with additional damping control and an impedance model under a dq coordinate system of an equivalent power grid; and drawing a Nyquist curve graph of the system according to the doubly-fed fan and the impedance model under the dq coordinate system of the power grid, and enabling the Nyquist curve to meet a generalized Nyquist stability criterion by adjusting the damping coefficient of the second-order damper, thereby enabling the system to be stable. According to the invention, the second-order low-resistance filter is added to the control link of the rotor side converter ofthe doubly-fed fan, so that the sub-super-synchronous oscillation of the fan can be effectively suppressed.

Description

technical field [0001] The invention relates to the technical field of grid-connected power generation of wind power generators, in particular to a sub-supersynchronous oscillation suppression method for grid-connected doubly-fed wind turbines with additional damping control. Background technique [0002] With the global energy crisis and the impact of fossil fuels on the earth's environment, more and more wind power generators have been put into use. At present, wind power has become another major power source after thermal power and hydropower. my country's wind power generation is mainly concentrated in the Three North region, which is far away from the load center, and the electrical distance between the wind farm and the load center must be reduced through series compensation transmission lines, but this method will cause sub-supersynchronous oscillation. For example: In March 2013, a subsynchronous oscillation of 8.1 Hz and a supersynchronous oscillation of 91.9 Hz occ...

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Problems solved by technology

Wang Yang et al. found that changing the integral parameters of the phase-locked loop in the doubly-fed fan control link can suppress the subsynchronous oscillation, but the parameter modification is more complicated; Tang Bingjie et al. changed the closed-loop pole of the impedance model by changing the current inner loop ratio parameter of the rotor-side converter position, thereby suppressing the sub-supersynchronous oscillation; Zhen Zijing et al. added damping control to the control link of the direct-drive permanent magnet synchronous machine grid-side converter and the control link of the photovoltaic inverter converter, which suppressed the occurrence of sub-supersynchronous oscillation in the wind-solar hybrid grid. Synchronous oscillation; for the sub-supersynchronous oscillation caused by the renewable energy hydrogen production system connected to the grid, Zhao Qiang et al. added an additional damping controller to the outer ring of the converter, which consists of a first-order high-pass filter and a second-order band-pass filter and proportional-phase-shift link; Chen Baoping suppresses subsynchronous oscillation and low-frequency oscillation by adding an additional damping controller to the excitation system of the fan and the control system of the grid-side converter

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