Direct hanging type energy storage converter redundancy control method and system based on port voltage state discrimination

Abstract

The invention discloses a direct hanging type energy storage converter redundancy control system based on port voltage state judgment, which comprises a central processing unit and a coprocessor, each phase comprises a phase switch (1) and a plurality of sub-modules (2), the sub-modules (2) are connected to a circuit through a bypass switch S, each sub-module (2) comprises a power module and a battery pack, and the power modules are connected to the central processing unit. The power module comprises an H-bridge bypass switch, a pre-charging switch group (4), a capacitor C, a first inductor L1 and a second inductor L2; the battery pack comprises a battery resistor R0 and a battery; when a plurality of power modules or battery packs of the medium-voltage direct-hanging type energy storage system break down, judgment and positioning of a fault state and bypass of a fault chain link are rapidly completed, seamless switching between a healthy operation state and a redundant operation state is achieved at the same time, power shortage caused by short-time shutdown of the system is avoided, and the service life of the system is prolonged. And loss caused by shutdown of the system due to faults of part of chain links is reduced.

Description

technical field [0001] The invention relates to the field of energy storage. The invention provides a redundant control method for a medium-voltage direct-mounted energy storage system, which is suitable for the field of energy storage. Background technique [0002] Energy storage technology is widely used because it can improve the utilization rate of new energy power generation, smooth active power fluctuations, and play a role in power system load shifting and valley filling. Among them, the cascaded energy storage power conversion system (Power Conversion System, PCS), also known as the direct-mounted energy storage power conversion system, has the advantages of modular structure and high safety, and has attracted widespread attention in high-voltage and large-capacity occasions. The quality of the control strategy directly affects the performance and reliability of the energy storage system. Due to the large power / capacity of a single unit of the direct-mounted energy ...

AI Technical Summary

Problems solved by technology

Due to the large number of power modules, the switching sequence is too complicated, and the calculation load on the central processing unit is too heavy, so it is impossible to accurately predict the output power or current within a unit control cycle

Compared with the redundant control method of the existing direct-mounted energy storage system, the biggest difference is that the existing patent is still based on vector control and carrier phase-shift modulation technology. The modulating voltage of the module needs to be recalculated and adjusted. At the same time, the triangular carrier phase angle of the healthy power module needs to be recalculated and distributed during the shutdown process. There is at least tens of milliseconds of shutdown time, which causes a large power shortage during this period. , unable to realize the requirement of continuous operation of the system and seamless switching of redundant state

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