A comparative study of voltage stability NVSI Index and load margin index

With the development of new energy generation technologies, photovoltaic (PV) power generation has gained widespread application as a clean and sustainable source of electricity. However, the intermittency and variability of PV generation pose new challenges to power system secure and stable operation. The WSCC 9-bus system is used in this paper to investigate the effect of PV integration on static voltage stability in power systems. An improved voltage stability index (NVSI) considering the new energy was used to measure the voltage stability of the access point of PV plant. Compared with the P-V curve and the classic load margin index (I_LM), even if the index value is less than 0, the NVSI index has still a better measure effect on voltage stability.