DC-link capacitors are a crucial component of many electronic converters because they aid in reducing dc-link voltage ripple, absorbing harmonics, and controlling the instantaneous power imbalance between the converter's frontend and rear-end. The dc-link's primary purpose is to operate as a continuous DC storage for the converter's injection current in response supply current. Uncontrolled dc-link capacitor voltage control can cause over-voltage and under-voltage, damaging the dc-link capacitor and disoperation of injection current. Due to the advantages of giving good accuracy of DC voltage and producing a clean and smooth regulated voltage with nearly no ripple, noise, and spike; a dc-link capacitor voltage control with self-charging technique is introduced. This paper reviews the recent self-charging technique applied to regulate the voltage of dc-link capacitor, which is typically categorized into two forms; (1) proportional-integral technique; and (2) fuzzy logic control (FLC) technique. In addition, the working principle, advantages, and disadvantages of both methods are discussed.
