An equivalent modeling method and device for wind farms considering low voltage ride-through characteristics

Abstract

The invention provides a wind power plant equivalent modeling method with the low voltage ride through characteristic considered. The method comprises the steps that action situations of Crowbars of all DFIG units are judged according to action area curves of the Crowbars of the DFIG units and the operation state of each unit in a wind power plant in the voltage dropping period, grouping is conducted on the units according to the action situations of the Crowbars, then, the units belonging to the same groups are combined by the adoption of the weighting volumetric method, parallel connection processing is conducted on current collection network impedance of the units belonging to the same groups, and equivalent models of two units of the wind power plant are obtained, wherein one equivalent unit represents the group of units where the Crowbars act during a power grid fault, the other equivalent unit represents the group of units where the Crowbars cannot act during the power grid fault and the equivalent input wind speed of the two equivalent units is solved by the adoption of the wind speed cubic weighting polymerization method. The invention further relates to a wind power plant equivalent modeling device with the low voltage ride through characteristic considered.

Description

technical field [0001] The invention relates to the technical field of renewable energy power generation, in particular to an equivalent modeling method and device for a wind farm considering low voltage ride-through characteristics. Background technique [0002] At present, as a representative of clean energy, the proportion of wind power in the power grid is increasing, and the mutual influence between wind power and power grid is becoming increasingly prominent. The interaction between wind power and power grid is currently mainly studied by digital simulation. Due to the small capacity and large number of wind turbines in a wind farm, if each wind turbine adopts a detailed model, the model order of the entire wind farm will be very high, which will seriously affect the efficiency of simulation analysis and the convergence of calculations. Moreover, when studying the impact of wind farms on the power grid, the focus is on the overall response of the wind farm, so the win...

AI Technical Summary

Problems solved by technology

For the DFIG unit using Crowbar, the rotor-side converter is blocked after the Crowbar is turned on, and the unit will enter the induction generator (IG) state from the DFIG state, and return to the DFIG state after the Crowbar is cut off. Aggregation inevitably introduces significant errors

However, the existing grouping methods of wind turbines cannot take into account the action of the crowbar of the DFIG unit, which will inevitably bring obvious dynamic errors to the equivalent model of the wind farm

Images