Uninterrupted Voltage Regulation Strategy for ES‐Based Smart Loads in Low‐Voltage Distribution Networks

ABSTRACT Electric spring (ES)‐based smart load (ES‐SL) has proven to be an effective measure to address the grid voltage fluctuation problem caused by the renewable energy sources (RES). However, the existing ES‐SL is highly dependent on the noncritical load (NCL). If the NCL does not operate or malfunctions, the ES‐SL will lose its voltage regulation function. In order to enable the ES‐SL to provide a reliable and continuous voltage regulation service, this paper analyzes the mathematical model of the ES‐SL under different NCL operating states in detail and proposes an uninterruptible voltage regulation strategy for the ES‐SL. This strategy decouples the current of ES‐SL by single‐phase dq transformation, which realizes the decoupling control of active and reactive power of ES‐SL. Meanwhile, the current reference value is updated in real time based on the derived mathematical model, so that the ES‐SL can operate normally to regulate the voltage during both normal and stopped operation of the NCL. Finally, the effectiveness of the proposed strategy has been verified by experiments.