5 results about "Doubly fed machine" patented technology

The invention discloses a method for discriminating transient synchronization stability of a multi-wind-power grid-connected system in an asymmetric short-circuit scene, which comprises the following steps of: firstly, calculating positive and negative sequence components of generator end voltage of double-fed wind turbine generators in an asymmetric short-circuit fault of a power grid, and then calculating positive and negative sequence q-axis components of the generator end voltage of each double-fed wind turbine generator; if the positive and negative sequence components of the output current of each unit in the system can be reasonably distributed and the q-axis components of the generator terminal voltage of all the doubly-fed wind turbine generators are corrected to be zero, the transient state of the system is stable under the asymmetric short-circuit fault of the power grid; otherwise, transient synchronous instability of the system occurs. According to the method, the coupling effect caused by control performance and response characteristics of different doubly-fed units between positive and negative sequence networks of the system under the asymmetric short-circuit scene of the power grid is comprehensively considered, and whether transient synchronization of the system is stable or not can be intuitively judged according to the criterion provided by the method.

The invention relates to a double-fed wind power plant equivalent modeling method considering low voltage ride through power characteristics, and belongs to the technical field of power system research. The method comprises the following steps: calculating the output power of a DFIG unit under LVRT, and obtaining a corresponding relation between a rotor current d / q axis component reference value and steady-state reactive power and active power during LVRT based on a voltage and flux linkage equation under a synchronous rotation coordinate and a wind power grid-connected dynamic reactive current; establishing a two-stage cluster division method based on the corresponding relationship to obtain a cluster division result; modeling a wind turbine, a fan transmission system and a stator and rotor side converter, and carrying out doubly-fed wind power plant parameter equivalence; and introducing an improved COA algorithm to identify control parameters of the doubly-fed wind power plant, determining to-be-identified parameters and an objective function, and optimizing and solving the parameters when the objective function is minimum, thereby completing equivalent modeling of the doubly-fed wind power plant. The objective of the invention is to solve the technical problems of power characteristic difference of a doubly-fed unit under a non-serious fault and difficult identification of parameters of a doubly-fed wind power plant.

The application discloses a kind of double-fed network unit positive and negative sequence current collaborative control method and system, it is related to double-fed unit network control technical field, the method includes: S1.data acquisition;S2.coordinate transformation and positive and negative sequence separation;S3.negative sequence current collaborative enabling logic design and negative sequence current instruction distribution;S4.network loop control;S5.positive and negative sequence reference voltage synthesis and generation rotor reference voltage.The application aims to solve how to improve positive and negative sequence separation method to adapt to double-fed unit variable speed operation characteristics and combined with network control, and how to design the collaborative control strategy of machine network side negative sequence current ring, to realize the high stability, high reliability operation of double-fed unit under the condition of weak power grid and asymmetric power grid.

The utility model discloses a tool for cleaning a radiating air duct of a generator of a GE doubly-fed unit, which comprises a mounting part, a positioning part and a cleaning part. The front surface of the mounting part is provided with a placing cavity; the driving assembly is arranged in the mounting part, one end of the driving assembly penetrates out of the mounting part and is in transmission connection with an external driving part, the external driving part comprises a servo motor, the driving assembly is driven by the servo motor to rotate, and then the cleaning assembly is driven by the driving assembly to rotate; the cleaning assembly is composed of a cleaning part and a transmission part, and the transmission part is also arranged in the mounting part and is in transmission connection with the driving assembly; through the design, the whole tool is convenient to carry, does not occupy space in the operation process, is simple in use mode and easy to operate, can utilize an electric tool, saves manpower and time, can easily solve the problem of high-temperature alarm caused by blockage of a heat dissipation air duct of the generator, meets the cleaning function, and improves the working efficiency. And the blank in the aspect of cleaning the radiating air duct of the GE fan generator in the prior art is filled.

The invention discloses a positive and negative sequence current cooperative control method and system for a doubly-fed network construction unit, and relates to the technical field of network construction control of the doubly-fed network construction unit, and the method comprises the steps: S1, data collection; s2, coordinate transformation and positive and negative sequence separation; s3, negative-sequence current collaborative enabling logic design and negative-sequence current instruction distribution are carried out; s4, network construction loop control; and S5, synthesizing the positive and negative sequence reference voltages and generating a rotor reference voltage. The invention aims to solve the problems of how to improve a positive and negative sequence separation method to adapt to variable-speed operation characteristics of the doubly-fed unit and combine with network construction control and how to design a cooperative control strategy of a machine-network side negative sequence current loop so as to realize high-stability and high-reliability operation of the doubly-fed unit under the conditions of a weak power grid and an asymmetric power grid.