Stator current sinusoidal control method for DFIG-DC (Double-Fed Induction Generator Direct Current) system

Abstract

The invention discloses a stator current sinusoidal control method for DFIG-DC (Double-Fed Induction Generator Direct Current) system, which enables a stator current to be sinusoidal, reduces a statorand rotor harmonic current and meanwhile, reduces a torque and a power pulse. According to the invention, a voltage sensor is not used, the stator current is directly adopted to represent a stator voltage, then a required rotor harmonic voltage is obtained by a double-fed motor model, and after the suitable harmonic voltage is added on a rotor side, sinusoidal processing of the stator current isimplemented; and such control method can reduce loss of the stator and rotor harmonic current, promote system operation efficiency and operation performance, and is an optimal control method very suitable for such topology.

Description

technical field [0001] The invention belongs to the technical field of new energy power generation, and in particular relates to a stator current sinusoidal control method of a DFIG-DC system. Background technique [0002] In the last ten years, DC microgrids based on new energy power generation equipment have been more and more researched and applied. The DC micro-grid has the advantages of high stability, simple grid connection, no reactive power loss, and wire cost saving, and most of the new energy generation units such as photovoltaics and wind power have DC ports, and most of the loads are DC loads, so for It is more economical, affordable and reliable to use DC micro-grid for these new energy power generation equipment. [0003] In new energy power generation, wind power generation based on doubly-fed motors occupies a high proportion, so in the study of new energy DC grid-connected, it is of great significance to study doubly-fed motors DC-grid-connected. At presen...

AI Technical Summary

Problems solved by technology

However, two converters are still needed, and when the slip control is not optimal, the capacity of the two converters is greater than the capacity of the slip times the power, and the cost is still high

On this basis, Spanish scholar G.D.Marques and others proposed a DC grid-connected structure of doubly-fed motors based on a single converter. The control rectifier bridge further reduces the cost of the topology structure, and only one converter needs to be controlled to further improve the reliability of control; however, due to the uncontrolled rectifier bridge on the stator side, the stator and rotor currents are distorted, resulting in power and torque with great pulsation

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