Cascaded symmetrical flying capacitor type topology static compensator based on hybrid switch

Abstract

The invention relates to a cascade symmetrical flying capacitor type topology static compensator based on a hybrid switch. The cascade symmetrical flying capacitor type topology static compensator comprises a symmetrical flying capacitor module and a coupling inductor which are connected in series; the symmetrical flying capacitor module comprises three groups of module units which are connected in series; each module unit comprises a first switch pair group, a second switch pair group and a third switch pair group, a first unipolar capacitor is arranged between the first switch pair group and the second switch pair group, a second unipolar capacitor is arranged between the second switch pair group and the third switch pair group, and the first switch pair group, the second switch pair group, the third switch pair group, the first unipolar capacitor and the second unipolar capacitor are connected in series. According to the cascade symmetrical flying capacitor type topology static compensator based on the hybrid switch, the efficiency of an inverter is improved, the number of used switching devices is reduced, losses are small, the heat dissipation requirement of a system is lowered, and meanwhile modularization and expandability of the system are kept.

Description

technical field [0001] The invention belongs to the technical field of static compensators, and in particular relates to a hybrid switch-based cascaded symmetrical flying capacitor topology static compensator. Background technique [0002] Static compensators based on multilevel inverters play a vital role in controlling grid voltage and regulating grid reactive power. The quality of inverter output voltage is closely related to the number of output levels of the inverter. More levels not only make the output waveform smoother, but also can effectively reduce electromagnetic interference and harmonic content. In practical applications, it can also increase System reliability. [0003] At present, the cascaded multi-level topology is widely used in static compensators, but because this structure requires a large number of switching devices, the complexity of system architecture and control increases, thereby affecting system efficiency and reliability. In order to reduce th...

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Problems solved by technology

Among them, the cascaded topology can be set symmetrically or asymmetrically according to its voltage. In most asymmetric structures, the power of different units is completely different. Due to the asymmetrical configuration, the power distribution is unbalanced, and the module units are not easy to replace. For high Power application environment, this method has a large limit

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