Single-phase self-excited wind power generation system

Abstract

The invention discloses a single-phase self-excitation wind power generation system. A single-phase self-excitation generator with adjustable excitation consists of a three-phase squirrel-cage motor, a capacitor with fixed excitation and a capacitor with adjustable excitation; the capacitor with adjustable excitation comprises a fixed capacitive value and an adjustable capacitive value, and the capacitive value adjustment is realized by IGBT duty ratio regulation and control; an alternating current load is connected with a bidirectional PWM converter in parallel, and coupled with an electric generator stator winding; an adjusting mechanism for adjusting voltage frequency of the electric generator is formed by a bidirectional converter and a storage battery; when the voltage control saturation of the capacitor with adjustable excitation is limited, the adjusting mechanism cooperatively controls the port voltage of the electric generator, and an active and reactive current reference tracking control policy is completed by adopting a 90-degree phase shift based single-phase voltage and current decoupling policy; and the active current reference is implemented by a frequency setting PI tracking controller, while the reactive current reference is implemented by a voltage amplitude PI tracking controller, and the reactive current reference value is the value, exceeding the saturation limited part, of the PI control output.

Description

technical field [0001] The invention relates to a single-phase self-excited wind power generation system, in particular to an independently operated single-phase self-excited wind power generation system applied to remote areas and islands without electric energy supply. Background technique [0002] With the increasingly serious energy crisis and environmental pollution, research on renewable energy has attracted widespread attention from researchers, especially in remote mountainous areas and islands where the power grid cannot reach. The problem of power supply has seriously restricted the improvement of the quality of life of local residents and border guards. Independently operated small wind power is an effective means to solve the above problems. At present, the widely used small wind power is single-phase self-excited wind power generation system, which is generally converted from a three-phase asynchronous motor. It has the advantages of compact structure, convenient...

AI Technical Summary

Problems solved by technology

In addition, the biggest defect of self-excited wind power is that the voltage regulation ability is poor, and the port voltage is easily fluctuated by the influence of generator speed, excitation capacitance and load current.

For this reason, two compensation strategies based on "C-2C" asymmetric excitation compensation and segmented additional shunt capacitors can solve voltage fluctuations, but cannot achieve flexible voltage adjustment under load fluctuations; The control strategy can match the output power of the generator in real time based on the load and generator power to ensure voltage stability, but the uncontrollable rectification produces harmonic interference, which affects the power supply quality of the generator and the load; based on back-to-back dual PWM conversion The generator control method can achieve precise control of voltage and frequency, but the cost is relatively high; in addition, the intermittency and volatility of wind energy itself makes the output voltage, frequency and output power of the generator fluctuate randomly, which cannot ensure the quality of power supply to the load, and increases the risk of self-sufficiency. Difficulty in controlling the excitation system

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