Single quadrant converter weak magnetic flux weakening control-based wind power system and operation method therefor

Abstract

An embodiment of the invention provides a single quadrant converter weak magnetic flux weakening control-based wind power system. The single quadrant converter weak magnetic flux weakening control-based wind power system provides unipolar armature voltage and armature currents to a rotor armature winding of a direct current motor via a single quadrant driving converter, unipolar excitation voltage and excitation currents are provided to a stator excitation winding of the direct current electric motor via an excitation converter, a direct current bus capacitor and a power frequency power grid are connected via a diode rectifier, the single quadrant driving converter and the excitation converter are used for replacing a bridge type reversible PWM converter, the diode rectifier is used for replacing a three phase PWM rectifier, the quantity and switch loss of power switch tubes are greatly reduced, and power fluctuation which is caused when a wind power generator rotating speed rapidly responds to wind speed change in order to improve wind energy utilization rates is compensated; technical problems of excess system cost and switch loss, damage risks caused by straight through short circuit faults and contradiction between wind energy utilization rates and power fluctuation caused by the three phase PWM rectifier and the bridge type reversible PWM converter can be solved.

Description

technical field [0001] The invention relates to the field of new energy power generation, in particular to a wind power system based on single-quadrant converter field-weakening control and an operating method thereof. Background technique [0002] Variable frequency transformer is a new type of grid interconnection equipment, which has unique advantages in solving many problems faced by wind power grid integration. On the one hand, variable frequency transformers can be used for grid-friendly transformation of constant-speed wind turbines to meet the grid's requirements for smooth output power of wind turbines, low-voltage ride-through capability, and reactive power support during grid voltage drops. On the other hand, using a variable frequency transformer to replace the power electronic converter in the traditional wind power system greatly reduces the capacity and cost of the power electronic device, and its overload capacity is also significantly enhanced. In view of i...

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Problems solved by technology

[0006] The embodiment of the present invention provides a wind power system based on single-quadrant converter field weakening control and its operation method, which is used to solve the excessive system cost and switching loss caused by the three-phase PWM rectifier and bridge reversible PWM converter. The risk of damage due to direct short circuit, the technical problem of contradiction between wind energy utilization rate and power fluctuation

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