Modular submarine power supply capacitor voltage ripple suppression method, system and controller

Abstract

The invention discloses a modular submarine power supply capacitor voltage ripple suppression method and system and a controller, and the method comprises the steps: taking each phase of bridge arm of a modular submarine power supply as a target object, and combining the equivalent capacitance values of an upper bridge arm and a lower bridge arm according to the principle that the upper bridge arm and the lower bridge arm are in parallel connection with the AC side current for shunting; and extracting a circulating current instruction value used for suppressing a capacitor voltage ripple component, obtaining modulation signals of the upper bridge arm and the lower bridge arm, and finally determining that the upper bridge arm and the lower bridge arm are put into sub-modules so as to realize ripple suppression of the capacitor voltage on the premise of meeting the requirements of direct-current side voltage input and alternating-current side voltage output. The problems that capacitor voltage ripples reduce the internal energy stability of the modular submarine power supply and increase the harmonic distortion rate of the output voltage on the alternating current side of the power supply are solved.

Description

technical field [0001] The invention relates to the field of modular submarine power supply control, in particular to a method, system and controller for suppressing voltage ripple of a modular submarine power supply capacitor. Background technique [0002] The sinusoidal characteristics of the output waveform of the modular subsea power supply (hereinafter referred to as "subsea power supply") are determined by the modulation signal and the modulation strategy. The modulation signal is mainly determined by the control method, and is related to the tracking effect of the control system on the command signal. Therefore, the modulation signal is generated. Key technologies in modular subsea power control process. For the modular submarine power supply, the modulation of the capacitor voltage ripple of the sub-module will excite harmonic components in the output voltage of the AC side. The research on the voltage ripple suppression method of the modular submarine power supply c...

AI Technical Summary

Problems solved by technology

Due to the complexity and symmetry of the modular multi-level structure, the analysis of the coupling relationship between its input and output is also relatively complicated, which poses great challenges to the research on capacitor voltage fluctuations and sub-module voltage balance.

[0003] Existing studies directly analyze the harmonic components contained in the sub-module capacitor voltage ripple, and use the harmonic circulation control method to effectively reduce the capacitor voltage ripple amplitude. This method suppresses the capacitor voltage ripple from the perspective of harmonic suppression , but the harmonic circulating current cannot directly reflect the ripple characteristics of the capacitor voltage, and it is urgent to explore a control method that uses the analysis and derivation of the capacitor voltage characteristics to obtain the circulating current command

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