The nitrogen pressure stabilization system is the core support of the valve cooling system for HVDC transmission. It can precisely maintain a constant pressure in the valve cooling circuit, prevent cavitation and boiling of the cooling medium to ensure heat dissipation efficiency, and also isolate air to prevent metal corrosion and impurities from invading. It directly affects the safety of the converter valve and the stability of the DC system. If the nitrogen consumption is too fast, it will disrupt the pressure balance, cause heat dissipation failure and accelerated corrosion. In severe cases, it may even cause the DC system to shut down. Therefore, analyzing and addressing this issue is necessary. It can identify the sources of leakage and equipment failures, formulate targeted solutions to prevent the expansion of faults, and ensure the reliable operation of the system and the safety of cross-regional energy transmission.
Shi et al. (2026) studied this question.