[Objective] In photovoltaic-concentrating solar power-battery energy storage system (PV-CSP-BESS) coordinated frequency regulation, unresolved response sequence coupling, control instruction conflicts, and state-of-charge (SOC) divergence remain critical challenges. This paper proposes a temporal coordinated control strategy based on state quadrant perception and adaptive frequency-domain decoupling to enhance system disturbance rejection capability.  

[Methods] First, an adaptive high-pass filter driven by the rate of change of frequency (RoCoF) is introduced into the BESS control loop to achieve temporal decoupling between transient high-frequency damping and steady-state low-frequency support. Second, to address long-term steady-state bias, a non-symmetric quadrant isolation mechanism based on Sigmoid function is proposed. This mechanism blocks reverse power feedback through the product of frequency deviation and SOC features, effectively preventing SOC drift in BESS. The adaptive time constant of the high-pass filter is dynamically adjusted in real time according to RoCoF magnitude, ensuring that BESS provides enhanced power support during severe transient disturbances while smoothly withdrawing during frequency recovery phases. The quadrant perception module monitors the algebraic signs of frequency deviation and RoCoF simultaneously: when both share the same sign, the system is in a perturbed state requiring immediate BESS intervention; when their signs differ, the system enters the recovery phase and BESS should withdraw to avoid power conflicts with CSP, thereby suppressing reverse power injection.  

[Results] Simulation results demonstrate that under step disturbances and low-inertia conditions, the proposed strategy effectively suppresses system transient extrema, with improvements in maximum frequency deviation and RoCoF reaching 21.6% and 43.2%, respectively, while reducing the risk of CSP main steam pressure violations. Under continuous random fluctuation scenarios, the equivalent cycling mileage of BESS decreases by 85.4%, the depth of discharge converges to 0.007%, and the steady-state SOC drift remains below 0.001%, achieving asymptotic stability. In scenarios where CSP output is constrained, photovoltaic reserve capacity is triggered to compensate for the steady-state active power gap, reducing the integral absolute error of frequency by 32.3%. Comparative analysis reveals that fixed-parameter decoupling control exhibits transient improvement at the cost of overall performance deterioration, whereas the proposed adaptive mechanism maintains robust performance across diverse operating boundaries.  

[Conclusion] The proposed strategy effectively mitigates power response conflicts between transient support and steady-state recovery, enhancing the dynamic complementarity and frequency stability support capability of multi-source heterogeneous equipment under complex operating boundaries. The approach provides a systematic solution for temporal coordination in hybrid renewable energy systems with diverse dynamic characteristics.