Core Selection Logic The DC power supply system panel provides an uninterruptible DC control power supply for protection, control, communication, and circuit-breaker closing circuits within the substation. Battery capacity selection must simultaneously satisfy two operating condition verifications, with the maximum value adopted as the final selection to ensure system safety and stability under contingency conditions: […]

AGC regulates active power to stabilize grid frequency; AVC regulates reactive power to stabilize nodal voltage. The two systems control two independent electrical quantities of the power grid and coordinate to guarantee safe and high-quality grid operation.

Current instantaneous trip protection (also referred to as instantaneous overcurrent protection, ANSI/IEC code 50) is the primary protection for transmission lines and transformers. Its core advantage is 0-second instantaneous tripping without intentional time delay.