Dynamic power regulation and optimization method of impedance source direct-drive permanent magnet wind power generation system in grid voltage fault

Abstract

The invention discloses a dynamic power regulation and optimization method for an impedance source direct-drive permanent magnet wind power generation system in a grid voltage fault. The dynamic powerregulation and optimization method includes: collecting a grid-connected point voltage U<abc>, and determining whether the U<abc> is less than a grid-connected preset voltage U<abc*>; acquiring an impedance source network capacitor voltage U<C1>, and determine whether the U<C1> is greater than an impedance source network capacitance threshold voltage U<C1N>; allowing the impedance source direct-drive permanent magnet wind power generation system to enter an electromagnetic torque self-tuning mode if Uabc<Uabc* and U<C1> > U<C1N>, obtaining an impedance source network inductor current set value I<L*> according to a drop state of the grid voltage; acquiring the wind turbine speed omega g, and determining whether the omega g exceeds the rated speed omega gN of the wind turbine; and adjustingthe pitch angle to make the impedance source direct-drive permanent magnet wind power system enter a constant speed mode if omega g> omega gN. The invention can avoid the Crowbar circuit, simplifiesthe system structure, and improves the response speed and the stability of the system.

Description

technical field [0001] The invention belongs to the field of grid-connected control of wind power generation, and in particular relates to a dynamic power adjustment and optimization method of an impedance source direct-driven permanent magnet wind power generation system under grid voltage failure. Background technique [0002] Impedance source (Z source, quasi-Z source, semi-quasi-Z source, etc.) direct-drive permanent magnet wind power generation system has the advantages of single-stage control, allowing the inverter bridge arm to pass through, and no need to insert dead time. In order to further improve the reliability of grid connection And reduce system cost provides a new way of thinking. At present, when the grid voltage fails, the impedance source direct drive permanent magnet wind power generation system continues to use the fault ride-through method of three-phase uncontrollable +Boost and dual PWM topology, and uses a crowbar circuit to balance the energy betwee...

AI Technical Summary

Problems solved by technology

At present, the impedance source direct drive permanent magnet wind power generation system continues to use the fault ride-through method of three-phase uncontrollable +Boost and dual PWM topology when the grid voltage fails, and uses a crowbar circuit to balance the energy between the machine side and the grid side. This method greatly increases the system cost and control difficulty, and reduces the economy and reliability of the system

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