A new frequency control method to enhance fault ride-through capability of VSC-HVDC systems supplying industrial plants

•Voltage sags is the most important issue of power quality, which can disrupt industrial process and impose huge costs on industrial plants.•A new frequency control method is proposed for the VSC-HVDC in order to improve the voltage stability in industrial plants during voltage sag.•The performance of the proposed method is investigated under 3LGF, DLGF, and SLGF conditions.•The proposed method maintains the minimum AC voltage at an acceptable value for very sensitive loads, when voltage drop occurs under severe faults.