Dual feedback asynchronous wind power generator rotor side inverter control method under unbalanced electric grid voltage

Abstract

The invention designs a control method of an inverter on a rotor side of a double fed wind induction generator. In the control method, a traditional PI adjustor is changed into a PIR adjustor, and a setting frequency Omega c in the PIR adjustor is set as a bisynchronous revolution angular speed Omega s, that is, a double frequency negative sequence component in disturbance quantity can be restrained completely, so the situation that power outputted to a power grid oscillates caused by impulsive motion of the electromagnetic torque of an engine because of unequal power grid voltage can be avoided. At the same time, the PIR adjustor can track a positive sequence component with frequency being zero and the double frequency negative sequence component in the forward path which are input in an astatic manner, thereby avoiding that unequal voltage aggravates the imbalance of stator current to cause a stator winding to heat because of serious imbalance. In addition, the control method realizes the control of the inverter on the rotor side of the generator under the condition of the unequal power grid voltage only through the replacement of the adjustor, the alteration thereof is simple, the effect is obvious, the design of complex elements is not involved, and the actualization is easy.

Description

technical field [0001] The invention relates to a control method for a rotor-side inverter of a doubly-fed asynchronous wind power generator, in particular to a control method capable of effectively suppressing the torque ripple of the generator caused by the unbalanced voltage of the grid without aggravating the height of the stator current The invention discloses an unbalanced doubly-fed asynchronous wind generator rotor-side inverter control method, which belongs to the technical field of wind power generation. Background technique [0002] With the subsequent growth of energy demand, large-scale wind farms have been planned and constructed all over the world, and the single-unit capacity of wind turbines is also increasing rapidly. At present, the megawatt-level variable-speed constant-frequency double-fed asynchronous power generation system has been widely used in wind power generation, and has become the mainstream of wind power farms around the world. The double-fed...

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to solve the problems existing in the prior art, and to provide a control method for the rotor-side inverter of the doubly-fed asynchronous wind power generator under unbalanced grid voltage, so as to prevent the doubly-fed asynchronous wind power generator from being caused by unbalanced power grid voltage. The high imbalance of the stator current and the torque ripple of the generator caused by it

Images