• N.Balavenkata Muni
• Dr.S.Sasikumar
• Dr.P.Nagaraju Mandadi

The recent developments in semiconductors and control equipment have made the voltage source converter based high voltage direct current (VSC-HVDC) feasible. Due to the use of VSC technology and pulse width modulation (PWM) the VSC-HVDC has a number of potential advantages as compared with classic HVDC, such as short circuit current reduction, rapid and independent control of active and reactive power, etc. This paper proposes a modified current limit strategy (MCLS) and a frequency hysteresis control (FHC) for improving the disturbance ride-through capability of a VSC-HVDC link supplying passive industrial installations. Since industrial loads are more sensitive to voltage drops than frequency deviations, it’s essential to guarantee the stability of voltage during severe faults. The development of the control methods includes three steps. First, the main factor that affects the ac voltage in the passive industrial system is analyzed in order to enhance the voltage stability more effectively. Secondly, according to the analytical results, the MCLS is proposed to increase the ac voltage in transient conditions. Thirdly, in order to make the MCLS have a better control result, the FHC is added to the VSC controller with the MCLS, which can also further enhance the ac voltage of the passive system. The simulation tests under metallic single-phase and three-phase faults are done in MATLAB/SIMULINK, and the results verify thevalidity of the control methods.

passive industrial installations, voltage stability, Voltage Source Converter (VSC), modified current limit strategy, frequency hysteresis control.

"Improvement of voltage stability and current limiting strategy for VSC-HVDC Systems using adaptive controllers", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.5, Issue 4, page no.1096-1101, April-2018, Available :http://www.jetir.org/papers/JETIR1804220.pdf

"Improvement of voltage stability and current limiting strategy for VSC-HVDC Systems using adaptive controllers", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.5, Issue 4, page no. pp1096-1101, April-2018, Available at : http://www.jetir.org/papers/JETIR1804220.pdf