基于固定时间补偿的风电并网电力系统频率波动快速平抑策略OA

The increasing penetration of wind power in power systems poses significant challenges to grid frequency stability due to the inherent volatility of wind power output.Traditional frequency regulation methods are insufficient to handle the rapid fluctuations caused by wind power variations,especially in systems with high wind power penetration.To address this issue,this paper proposes a fixed-time compensation(FTC)-based fast frequency regulation strategy for wind power integrated power systems,specifically designed for doubly-fed induction generator(DFIG)-based wind turbines. The proposed strategy consists of two main components:a fixed-time observer(FTO)and a linear state error feedback(LSEF)controller.Firstly,considering the frequency dynamic response model of a power system integrated with high-proportion DFIGs,a FTO based on fractional power feedback is designed,which can accurately estimate both the true system frequency deviation and the aggregated unknown disturbances within a predetermined finite time,independent of initial conditions.The FTO captures temporal-spatial correlation information from system frequency dynamics,providing deterministic observation for rapid frequency regulation initiation.Secondly,the observed frequency deviation is integrated with an LSEF controller to form the complete FTC strategy.The LSEF generates control signals based on the error between observed and reference frequency values,while the FTO's disturbance estimates are actively compensated in real-time.This integrated approach enables rapid suppression of frequency fluctuations and reduction of transient frequency deviations. The theoretical foundation of the proposed method is rigorously established.The convergence and stability of the FTC controller are analyzed using Lyapunov stability theory,while parameter tuning rules are derived based on fixed-time stability theory.This ensures the FTO's convergence time remains bounded regardless of initial conditions. Simulation results on Matlab/Simulink platform demonstrate the effectiveness of the proposed method.Under 25%wind power penetration with random wind speed conditions(mean 8.42 m/s),the FTC strategy achieved significant performance improvements.Compared to the maximum power point tracking(MPPT)mode,it reduced the maximum frequency deviation by 97.76%(over-frequency)and 88.77%(under-frequency),and decreased the root mean square of frequency deviation by 78.86%.The duration during which frequency deviation exceeded±0.03 Hz was shortened by 61.69%,while the mean absolute deviation of DFIG output was reduced by 76.56%.The covariance between system frequency and wind power output decreased by 96.72%,indicating effective decoupling of wind power fluctuations from frequency variations.Under higher penetration scenarios(50%wind power),the FTC strategy maintained its superior performance.Compared to MPPT,it reduced the maximum frequency deviation by 84.27%(over-frequency)and 100%(under-frequency),and decreased ΔfRMS by 78.17%.The PMAD was reduced by 90.63%,demonstrating consistent performance across different penetration levels.Comparison with other control strategies revealed the advantages of the FTC approach as well.Against fixed-gain droop control,the FTC strategy reduced ΔfRMS by 69.41%under 25%penetration and by 65.04%under 50%penetration.Compared to variable-gain droop control,these improvements were 67.50%and 66.92%respectively.Against active disturbance rejection control,the improvements were 64.38%and 61.26%respectively. The proposed method also showed strong robustness in challenging conditions.With±10%parameter perturbations in generator inertia constants and 100 ms communication delays,the system maintained stable performance without requiring controller retuning.Validation on the IEEE 39-bus system further confirmed the method's applicability in large-scale complex grids,with ΔfRMS reduced to 0.008 Hz under FTC compared to 0.098 Hz under MPPT. The following conclusions can be drawn from the theoretical analysis and simulation results:(1)The FTO effectively estimates system disturbances and true frequency deviation within predetermined time bounds,providing a deterministic foundation for fast frequency regulation.(2)The integrated FTC strategy significantly outperforms conventional control methods in suppressing frequency fluctuations,with performance improvements consistently exceeding 60%across all evaluated metrics.(3)The method demonstrates strong robustness against parameter uncertainties and communication delays,making it suitable for practical implementation in real-world power systems.(4)The theoretical framework based on Lyapunov stability and fixed-time stability provides reliable guidelines for controller parameter tuning and system implementation. In summary,the proposed FTC strategy offers an effective solution for fast frequency fluctuation suppression in high-wind-penetration power systems,with demonstrated performance advantages,theoretical soundness,and practical applicability.