Abstract: To address the issue of frequency oscillation in variable-speed air conditioners caused by elevated discharge temperatures under high ambient and high compression ratio conditions, a compressor frequency control framework is developed. The framework introduces a dynamic discharge temperature threshold and target frequency mapping based on risk levels, integrates rate limiting and anti-windup compensation in the speed regulation loop, and establishes a coordinated control and parameter tuning procedure that balances discharge temperature regulation with actuator rate and amplitude constraints. Experimental results show that, compared with conventional fixed-threshold logic, the proposed method reduces the frequency oscillation amplitude from±10 Hz to ±2 Hz ~±4 Hz, significantly shortens protection activation and recovery times, and mitigates fluctuations in airflow and room temperature while improving overall energy efficiency. Without any hardware modification, the proposed framework effectively enhances system stability and operational efficiency.

Key words: Exhaust temperature, Compressor, Control, Experimental study