基于有限时间观测器的三相混合变换器超螺旋滑模控制OA

In the context of energy transition and carbon neutrality goals,distributed renewable energy technologies have accelerated the adoption of microgrid systems.Compared to traditional bidirectional converters,three-phase hybrid converters offer advantages such as high efficiency,increased power density,and lower maintenance costs,making them suitable for energy exchange in microgrids.However,these converters face challenges such as slow dynamic response,susceptibility to disturbances,and periodic current distortion due to inherent structural limitations. In the DC-link voltage regulation loop,an improved super-twisting sliding mode controller(ISTSMC)is designed.The core mechanism of ISTSMC is an exponential adaptive gain based on the sliding mode surface distance|s|.It allows the controller gains to dynamically adjust according to the system state:when far from the sliding surface,gains are significantly increased to boost the dynamic response speed,conversely,when approaching or moving near the surface,gains automatically reduce towards their base value to effectively suppress high-frequency chattering.Load power and external disturbances are treated as a lumped disturbance and compensated for using a finite-time extended state observer(FTESO).The FTESO leverages dual-power terms(α1＜1 and β1＞1)and appropriate observer gains(ε1,ε2,ε3,ε4)to satisfy Hurwitz stability.By integrating the ISTSMC with the FTESO,the DC-link voltage can achieve superior dynamic and steady-state performance.Finally,the stability of the FTESO-ISTSMC system is analyzed using the Lyapunov function,with a general derivation framework.Furthermore,to mitigate periodic abrupt changes in the input currents of a three-phase hybrid converter,the design of the current inner loop controller considers the total input current on the AC side of the hybrid converter as the feedback value of the control loop.Then,its control objective is changed to achieving sinusoidal shaping of the total input current.Meanwhile,PI repeat control is adopted to attain static control of sinusoidal fundamental waves and harmonic currents. Finally,the experimental verification was conducted on a 2.25 kW prototype.Utilizing the ISTSMC-FTESO strategy,the hybrid converter demonstrates effective operation in rectifying and inverting modes.During rectification,the power factor approaches 0.999,while the total harmonic distortion is 3.71%,compliant with the IEEE 519 standard.During inversion,the power factor approximates-0.999.Energy exchange between its two sides is accomplished by transitioning between rectification and inversion modes.PI control,super-twisting sliding mode control(STSMC),and FTESO-ISTSMC are compared.Under the condition of sudden load drop,FTESO-ISTSMC reduces dynamic response time by 73.5%and 60.7%,and decreases DC-link voltage dip magnitude by 68.9%and 58.1%,compared to PI control and STSMC,respectively.Under the condition of a sudden load increase,the dynamic response time is reduced by 79.0%and 58.0%,and the DC-link voltage rise magnitude is decreased by 68.4%and 60.0%.Under reference voltage rise conditions,the dynamic response time is reduced by 47.6%and 39.3%and the voltage overshoot magnitude is reduced by 77.8%and 46.7%.During the reference voltage drop,the dynamic response time is reduced by 36.5%and 29.4%,and the voltage overshoot magnitude is reduced by 75.2%and 14.7%.For a 10%input voltage drop,the dynamic response time is reduced by 95.3%and 61.7%,with no significant drop in the DC side voltage.Experimental results demonstrate that the proposed scheme maintains stable operation under load transients,voltage step variations,and input voltage fluctuations,providing an effective solution for high-reliability operation of hybrid converters in microgrid applications.