Abstract: Against the background of the “dual carbon” goal and the construction of a new-type power system, the 35 kV collector systems of large-scale centralized photovoltaic power stations feature a high cable ratio and large capacitive current, while traditional grounding methods tend to cause overvoltage and protection issues. Based on the power-frequency arc extinction theory and the RLC damped oscillation mechanism, an overvoltage suppression and parameter matching model for low-resistance grounding systems is established, and derives refined calculation methods for neutral point resistance, grounding transformer capacity, and zero-sequence CT transformation ratio. A three-in-one collaborative optimization scheme integrating parameter design, overvoltage suppression and protection sensitivity is proposed and verified through engineering practice. The results show that the proposed method can limit the single-phase grounding steady-state overvoltage within 1.5 times the phase voltage and keep the transient overvoltage below 2.0 times the phase voltage, with the zero-sequence protection sensitivity coefficient stably greater than 2, which effectively improves the operational safety and grid-connected stability of photovoltaic power stations.