Control method for virtual active power filter of alternating-current and direct-current hybrid microgrid

Abstract

The invention discloses a control method for a virtual active power filter of an alternating-current and direct-current hybrid microgrid. The control method adopts predictive current control for performing energy exchange on the virtual active power filter, an alternating-current bus Ua, an alternating-current bus Ub, an alternating-current bus Uc, an alternating-current microgrid and a large power grid in the virtual active power filter of the alternating-current and direct-current hybrid microgrid. Through the control method, the virtual active power filter of the alternating-current and direct-current hybrid microgrid can work in three modes of the active power filter, rectification and inversion; the active power filter can be used for filtering harmonic waves of the hybrid microgrid through compensation reactive power, so that the electric energy quality is improved; and the rectification mode and the inversion mode can enable the alternating-current and direct-current hybrid microgrid to carry out energy bidirectional flow, and also can filter the harmonic waves of the hybrid microgrid through the compensation reactive power, so that the electric energy quality is improved.

Description

technical field [0001] The invention relates to a hybrid microgrid, in particular to a control method for a virtual active power filter of an AC / DC hybrid microgrid. Background technique [0002] The equipment we use can be divided into AC loads and DC loads. In the past, AC loads were mainly used, but now more and more DC loads are used, thus forming a situation where a large number of AC equipment and DC equipment coexist. [0003] In an independent AC microgrid or DC microgrid, multiple AC-DC conversions are required to meet the access requirements of distributed power sources and loads. At the same time, due to the extensive use of power electronic equipment and nonlinear loads in the AC-DC hybrid microgrid, especially the AC-DC hybrid microgrid that uses photovoltaics as the main distributed power source in distributed power generation, it is extremely vulnerable to natural conditions such as sunlight and wind. , generating harmonics. [0004] In addition, due to the ...

AI Technical Summary

Problems solved by technology

The new type of power converter composed of these switching tubes may not work properly, which may cause a short circuit in severe cases. Harmonics may also cause partial discharge of the capacitor on the DC side of the microgrid, accelerate the aging of the capacitor dielectric, and shorten the service life. The possible resonance problem can also cause The capacitor is burned due to overvoltage and overload

The harmonics in the AC bus will also generate corresponding harmonic voltages in the DC bus, so that the harmonics on the AC side will be transmitted to the DC side, which will have a great impact on the safe and stable operation of the DC microgrid.

[0005] Traditional large power grid active power filters mainly use single-cycle control, hysteresis current control, space vector modulation, deadbeat control, sliding mode control, repetitive control, fuzzy control, adaptive control, iterative self-learning control, Passive control, artificial neural network control methods, these controls can only perform one-way harmonic control, but cannot make the energy of the hybrid microgrid flow bidirectionally

The AC / DC hybrid microgrid adopts constant voltage constant frequency control and virtual synchronous generator control, which can only make the hybrid microgrid energy flow bidirectionally, but cannot control the harmonics of the hybrid microgrid.

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