With the integration of high penetration renewable energy

the increasing disparities in power source structures across interconnected power system control areas have become prominent. In some control areas

the growing share of renewable energy and reduced conventional generation units lead to higher frequency regulation demands but diminished control capabilities. The traditional control performance standard (CPS) under tie-line power and frequency bias control (TBC) mode defines assessment thresholds using frequency deviation coefficients

but fails to account for the impact of the actual power source structures in different control areas. This inadequacy becomes increasingly evident in the renewable energy dominated power systems. This study first analyzes the assumptions and principles of existing CPS

revealing its limitations in high proportion renewable energy systems. Subsequently

the concept of control area inherent ACE standard deviation is proposed to determine assessment thresholds

forming an improved CPS methodology. A comparative analysis with the original CPS demonstrates that the refined approach ensures greater fairness and rationality. Case studies further validate that the proposed method outperforms conventional CPS in addressing structural disparities across control areas.