Method and system for preventing direct current grounding relay protection maloperation

The invention discloses a DC grounding relay protection maloperation prevention method and system, and the method comprises the steps: carrying out the following different anti-interference strategies for an intelligent discrimination tripping circuit and a non-discrimination direct tripping circuit according to the charging and discharging characteristics of a capacitor and the fault characteristics of a power system; direct current grounding relay protection maloperation is prevented through delay and fault discrimination combined tripping; and for an undiscriminated direct tripping circuit, direct-current grounding relay protection maloperation is prevented through delay and high-power tripping starting. The grounding device is used for grounding a direct-current system of a power system substation, and can prevent the direct-current system from being influenced by grounding capacitance to cause protection mis-tripping caused by short-time conduction of cable loops such as a substation failure starting loo