Novel impedance source direct-drive permanent magnet wind power generation system and control method thereof

Abstract

The invention discloses a novel impedance source direct-drive permanent magnet wind power generation system and a control method thereof. The impedance source direct-drive permanent magnet wind powergeneration system comprises fan blades, a permanent magnet synchronous generator, a three-phase uncontrollable rectifier, an impedance source network, a three-phase six-switch inverter bridge arm, a filtering inductor and a controller. The control method is characterized in that impedance source network inductive currents iL1, impedance source network capacitor voltage VC2, the position angle theta r and rotation speed omega r of the permanent magnet synchronous generator, three-phase grid connection voltage ega, egb and egc and three-phase grid connection currents ia, ib and ic are sampled, and permanent magnet synchronous generator rotation speed stability, impedance source network capacitor voltage stability and grid connection power factor control can be achieved by one controller. Bythe novel impedance source direct-drive permanent magnet wind power generation system and the control method thereof, effective grid connection under large wind speed change can be achieved, device voltage stress can be lowered, and accordingly system reliability can be increased, and cost can be lowered.

Description

technical field [0001] The invention belongs to the field of grid-connected control of wind power generation, and in particular relates to a novel impedance source direct-drive permanent magnet wind power generation system and a control method thereof. Background technique [0002] As a clean and renewable new energy generation method, wind power has developed rapidly this year. The converter device is the core device in the wind power generation system. It not only directly affects the reliability and stability of the wind power generation system, but also relates to the overall system efficiency and cost. Compared with the voltage-type PWM inverter, the impedance source inverter has the advantages of allowing the inverter bridge arm to pass through and single-stage control. At present, the impedance source inverters used in wind power generation include Z-source inverters, quasi-Z-source inverters, etc. Traditional impedance source direct-drive permanent magnet wind power...

AI Technical Summary

Problems solved by technology

At present, the impedance source inverters used in wind power generation include Z-source inverters, quasi-Z-source inverters, etc. Traditional impedance source direct-drive permanent magnet wind power generation When the step-up ratio of the impedance source inverter has reached the limit value, the voltage can only be increased by increasing its modulation degree, and at this time it will inevitably cause the impedance source network capacitance and the three-phase six-switch inverter bridge arm to bear a greater voltage stress

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