Multi-mode operation control method of single-phase cascaded optical storage hybrid system

Abstract

The invention discloses a multi-mode operation control method of a single-phase cascaded optical storage hybrid system. The daytime photovoltaic power generation period of peak-hour price is defined as a fluctuation suppression mode according to the difference between peak-hour price and off-peak price of time price and the characteristic that the photovoltaic power generation system only generates electricity in daytime, and the power fluctuation in photovoltaic power generation is suppressed by the storage cell to assist discharging of the photovoltaic cell. The daytime photovoltaic power generation period of the off-peak price is defined as a self-charging mode, and the storage cell is utilized to absorb all the active power emitted by photovoltaic power and the whole photovoltaic grid-connected system only compensates for the reactive power. The non-generation period of night photovoltaic power is defined as a night mode, and the photovoltaic cell is regarded as a static synchronous compensator and the storage cell completes the charge and discharge work at night. The night peak hour electricity price period is defined as the night discharge working state and the night off-peakhour electricity price period is defined as the night charging working state according to the time-of-use electricity price. The all-day economic operation of the photovoltaic grid-connected system can be guaranteed.

Description

technical field [0001] The invention relates to photovoltaic power generation technology, in particular to a multi-mode operation control method of a single-phase cascaded photovoltaic-storage hybrid system. Background technique [0002] The single-phase cascaded solar-storage hybrid system has the characteristics of smoothing photovoltaic power fluctuations, grid connection without transformers, wide-range reactive power compensation, and independent maintenance of photovoltaics and batteries, and has been widely used in the field of photovoltaic power generation. At present, most of the research on cascaded solar-storage hybrid systems focuses on improving the quality of grid connection, such as "Research on Control Strategy of Single-phase Hybrid Cascaded Photovoltaic Inverter with Energy Storage" (Guiyuan, Hubei University of Technology, 2018) A coordinated control method for cascaded photovoltaic grid-connected inverters is disclosed, which optimizes the effect of energ...

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Problems solved by technology

However, this method only considers the situation with sufficient light, and the night time period with insufficient light or even no light is not considered.

However, the effective power generation time of the photovoltaic system is concentrated in the daytime, and its power generation peak period is from noon to afternoon, while the power consumption peak of the power system occurs in the evening, and it is the off-peak period of power consumption at noon, which leads to serious problems. The contradiction between power generation and power consumption, coupled with the popularization of time-based electricity prices, obviously, the operation of one working mode can no longer meet the requirements of photovoltaic grid-connected systems, and a more economical multi-mode power coordinated distribution is urgently needed method

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