The study of two improved photovoltaic grid-connected control strategy basing the Sliding Mode

To simplify grid-connected inverter control system, improve dynamic characteristics of the system, and reduce the hardware and software cost of inverter control design, the exponential sliding mode control (ESMC) and the square root sliding mode control (SRSMC) were designed. Theory testify of the sliding mode approach law applied in the grid-connected inverter was completed, and system stability was proven using Lyapunov theorem. In order to reduce the intensity of chattering, the sliding mode control (SMC) function may smooth deal with. The unit to control continuous method is used to improve the two SMC systems, it can enable smooth after the control with high gain characteristic nearby the cut surface, and it has the resistance disturbance and parameter perturbation ability. Finally, compared with the two control methods, the result had proven the proposed modified exponential sliding mode control strategy accurate and the system has a better control precision and tracking characteristic.