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The penetration of solar energy in the modern power system is still increasing with a fast growth rate after long development due to reduced environmental impact and ever-decreasing photovoltaic panel cost. Meanwhile, distribution networks have to deal with a huge amount and frequent fluctuations of power due to the intermittent nature of solar energy, which influences the grid stability and could cause a voltage rise in the low-voltage grid. In order to reduce these fluctuations and ensure a stable and reliable power supply, energy storage systems are introduced, as they can absorb or release energy on demand, which provides more control flexibility for PV systems. At present, storage technologies are still under development and integrated in renewable applications, especially in smart grids, where lowering the cost and enhancing the reliability are the main tasks. This study reviews and discusses several active power control strategies for hybrid PV and energy storage systems that deliver ancillary services for grid support. The technological advancements and developments of energy storage systems in grid-tied PV applications are also reviewed.

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PV and battery systems have been widely deployed in residential applications due to increasing environmental concerns and fossil energy prices. Energy management strategies play an important role in reducing energy bills and maximize profits. This paper first reviews the state of energy management problems, including commonly used objectives, constraints, and solutions for PV and battery applications. Then, a comparative study of different energy management strategies is conducted based on a real applied product and household profile. Moreover, results are discussed, and suggestions are given for different scenarios. Finally, conclusions and insights into future directions are also provided.

With the increasing penetration of solar energy, a huge amount of fluctuating power is injected into the power grid, which has a negative influence on power quality (e.g., voltage fluctuation). To solve this problem, power ramp rate control has been introduced in grid codes. In recent years, hybrid energy storage systems have been widely used in many applications for limiting the ramp rate of the power, due to their control flexibility. Currently, the integration of supercapacitors in such hybrid systems is still a hot issue to extend the battery lifespan and improve the dynamic performance. In this paper, an adaptive ramp-rate control strategy is conducted using low-pass filters, which can change the filter time constant to reduce the overall battery cycles. The results show that the proposed strategy can effectively reduce the battery cycles by about 20% compared to the traditional two-stage strategy during days with fast-moving clouds.