A Method for Suppressing Supersynchronous Oscillation of Doubly-fed Fan Grid-connected with Additional Damping Control

Abstract

The invention discloses a method for suppressing sub-supersynchronous oscillation of doubly-fed fan grid-connected with additional damping control. Aiming at the sub-supersynchronous oscillation phenomenon caused by doubly-fed fan connected to the grid through series-compensated transmission lines, the converter on the rotor side of doubly-fed fan is controlled A second-order low-cut filter is added to the link to suppress its generation. First establish the mathematical impedance model of the double-fed fan with additional damping control in the dq coordinate system, and the impedance model in the dq coordinate system of the equivalent grid; then draw the Nyquis of the system according to the impedance model in the double-fed fan and the grid dq coordinate system By adjusting the damping coefficient of the second-order damper, the Nyquist curve satisfies the generalized Nyquist stability criterion, so that the system is stable. The invention can effectively suppress the sub-supersynchronous oscillation of the fan by adding a second-order low-resistance filter to the control link of the converter on the rotor side of the double-fed fan.

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...

AI Technical Summary

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

Images