A grid-connected control method for double-fed variable-speed pumped storage units under pumping conditions

Abstract

The invention discloses a grid-connected control method of a doubly-fed variable-speed pumped-storage unit under the pumping condition. First, ButterWorth low-pass filtering is performed on the collected stator voltage to obtain the filtered stator voltage, and then the grid voltage is locked. Phase, to get the grid voltage phase, use the phase to do Park transformation on the grid voltage and the filtered stator voltage, and obtain the d, q axis components of the grid voltage and the d, q axis components of the stator voltage in the rotating coordinate system; The four voltage components are closed-loop controlled, and the output of the closed-loop control is used as the rotor current compensation amount and the rotor position angle compensation amount to keep the stator voltage consistent with the grid voltage in amplitude and phase. When it is detected that the amplitude difference and phase difference between the stator voltage and the grid voltage are less than a given error and maintain several cycles, the grid-connected operation is performed. This method has the characteristics of fast dynamic response, high precision and good robustness.

Description

technical field [0001] The invention belongs to the application field of a double-fed variable-speed pumped storage unit in pumped storage, and in particular relates to a grid-connected control method for a double-fed variable-speed pumped storage unit under pumping conditions. Background technique [0002] The double-fed variable-speed pumped storage unit has the advantages of flexible output, quick response, wide application range, and high energy conversion efficiency. When applied to pumped storage, it can meet the needs of power grid frequency regulation and voltage regulation, and solve the problems caused by water head changes and output fluctuations. The resulting problem of reduced efficiency of the pump turbine. According to system requirements, doubly-fed variable-speed pumped storage units in pumped storage mainly operate in two working conditions: pumping water and power generation. In-depth study of grid connection process. [0003] In the case of pumping wat...

AI Technical Summary

Problems solved by technology

[0004] In order to solve the problem of inrush current caused by phase steady-state static difference and stator harmonic voltage in the actual grid-connected process, the present invention proposes a grid-connected control method under the pumping condition of double-fed variable-speed pumped storage unit, which is a Grid connection control method based on ButterWorth low-pass filter

Images