Electromagnetic Interference on Secondary Systems of UHVDC Convertor Substation Caused by Ground Potential Rise

This paper analyzed the effect of transient ground potential rise on the secondary system of UHVDC convertor substation and searched for better grounding ways for suppressing interference voltage in secondary cables' core wires caused by ground potential rise. Through simulation of the real secondary cables' layout, we proposed that cable's shielding sheath should be grounded only in protecting cabin for a single secondary cable harness with armor double-ended grounded. Through test on a four-segment secondary cable carried out in one UHVDC convertor substation, we found it's benefit to ensure shielding sheath be grounded both in phase B's operating cabinet and terminal box at least. Besides, for the purpose of suppressing interference on cores caused by ground potential rise, through comparison we can get one of the most effective grounding way is guaranteeing armor and shielding sheath grounded both in protecting cabin and terminal box, meanwhile, the armor and sheath among operating cabinet should be grounded only in phase B's cabinet.