Multi-level comprehensive evaluation method for reliability of energy storage grid-connected system

Abstract

The invention discloses a multi-level comprehensive evaluation method for reliability of an energy storage grid-connected system, a top-down hierarchical state space of a BESS grid-connected model is constructed, various operation strategies and equipment operation characteristics are comprehensively considered, a system cooperative work mechanism is simulated through a reliability parameter coupling calculation method, a state space multi-level analysis method of the BESS grid-connected system is provided, an evaluation result truly reflecting the reliability of the BESS grid-connected system is obtained through calculation, and the engineering application requirement for carrying out BESS grid-connected system reliability evaluation under the actual working condition is met.

Description

technical field [0001] The invention relates to the technical field of battery energy storage system performance evaluation, in particular to a multi-level comprehensive evaluation method for the reliability of an energy storage grid-connected system. Background technique [0002] In recent years, with the widespread implementation of renewable energy, the reliability of power systems has been affected by the intermittent and fluctuating characteristics of distributed generation (DG) such as wind power and photovoltaics. In order to stabilize the fluctuation of renewable energy processing and restrain its impact on the grid, BESS (battery energu storage system) is increasingly integrated into the grid. BESS has high energy density, fast cycle response, and low construction environment requirements, making it an ideal device for improving system stability and reliability. However, the safety features and operation strategies of large-capacity BESS have a great impact on the ...

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Problems solved by technology

[0012] 1) The existing technology has established a complete BESS grid-connected system model, which explains the mechanism of various faults in the BESS grid-connected system. The reliability of a single component has been studied in depth, but the BESS grid-connected system is essentially a large number of components The reliability evaluation of a complex system formed by multi-level coupling considers the reliability of collaborative work among complex systems. The existing reliability evaluation methods often focus on the reliability of individual components under laboratory preset conditions. Component parameters are simply accumulated, ignoring the cooperative working characteristics of each component, and it is difficult to accurately reflect the working reliability of the BESS grid-connected system under actual working conditions

[0013] 2) The reliability assessment of BESS grid-connected system in the existing technology often relies on the online monitoring data of each part of the system, and adopts the empirical estimation method to set the reliability threshold. The accuracy of reliability assessment is related to the accuracy of data monitoring. The environment conditions are complex and the operation strategies are diverse, and the reliability parameter estimation of each component has different degrees of deviation. If the actual working conditions are not considered, the operating state and its own safety characteristics of the complex system are directly preset, and the reliability threshold is established based on experience. , then the monitoring data of the BESS grid-connected system in normal operation will easily exceed the preset threshold, resulting in misjudgment of faults, making the reliability evaluation results unable to reflect the real operating status of the BESS grid-connected system

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