摘要
Abstract
In the context of economic globalization,the escalating demand for electricity from residential,commercial,and industrial sectors has accelerated the depletion of non-renewable energy resources such as coal,oil,and natural gas.Coupled with mounting environmental concerns,this trend has prompted global efforts to accelerate the development of renewable energy technologies,with solar energy emerging as a primary focus.As part of this international movement,China has been steadily advancing its sustainable energy development strategy to optimize energy structure and reduce carbon emissions.
However,the inherent limitations of distributed power generation systems—including intermittent power output,low operational flexibility,and grid integration challenges—necessitate innovative solutions.Microgrids have emerged as a promising technical approach to address these issues,particularly in remote or off-grid areas where reliable power supply cannot be guaranteed by conventional utility grids.Presently,microgrid systems are classified into three operational architectures:DC microgrids,AC microgrids,and hybrid AC/DC microgrids.The hybrid configuration,which integrates the complementary advantages of both AC and DC systems,has become a focal area of contemporary research.
For isolated microgrids operating in island mode,the photovoltaic(PV)storage AC/DC hybrid system represents a critical technological solution.This system architecture typically comprises PV generation units,battery energy storage systems(BESS),AC/DC busbars,interlinking power converters,and bidirectional AC/DC loads.Given the inherent volatility and unpredictability of standalone PV systems,BESS plays a pivotal role as an energy buffer to mitigate power imbalances.To ensure efficient solar energy utilization while preventing premature battery degradation from overcharging/discharging,a sophisticated collaborative power regulation mechanism must be established among generation,storage,and load components.
This paper proposes an adaptive power coordination control strategy specifically designed for islanded PV storage AC/DC microgrids.The control architecture adopts a hierarchical structure:(1)the energy storage system maintains DC bus voltage stability through droop control or model predictive control algorithms;(2)the interlinking converter implements a V/f(voltage-frequency)control strategy to establish stable AC subnet parameters;and(3)the DC bus voltage serves as the system's power balance reference,enabling autonomous power coordination among PV arrays,BESS,and converters.
Simulation validation on a real-time digital simulator demonstrates the strategy's efficacy across three operational scenarios:
(1)Under varying environmental conditions(temperature fluctuations,irradiance changes),the PV system achieves accurate maximum power point tracking(MPPT)with>98%efficiency.
(2)The V/F-controlled interlinking converter maintains AC subnet voltage within±2%of rated value and frequency stability within±0.1 Hz,providing reliable reference signals for downstream loads.
(3)During abrupt load transitions(±50%step changes in AC/DC demand),the DC bus voltage remains regulated within 3%deviation from nominal value,while the BESS exhibits smooth power absorption/injection characteristics following predefined state-of-charge(SOC)constraints.
This control paradigm not only ensures stable operation of islanded microgrids but also prolongs energy storage system lifespan through intelligent power dispatch,offering a viable solution for decentralized renewable energy deployment in remote regions.关键词
光伏发电/储能系统/光储一体孤岛微电网/自动功率协调Key words
photovoltaic power generation/energy storage system/AC-DC hybrid microgrid/automatic power coordination分类
信息技术与安全科学
