Development of Intelligent Control Strategy for Dynamic Voltage Restorer Based on Energy Storage System

With the global energy crisis and environmental problems becoming more and more serious, the development of renewable energy and energy storage system application technologies has attracted more and more attention. However, the power quality disturbances would be caused due to the nonlinear loads in the local grid system when the renewable energy is connected to the power grid with the power electronic devices, such as inverters. Once the penetration rate of the renewable energy in the power grid is large enough, the short-time fault wouldlead to the tripping of renewable energy. In addition, the synchronous detection and control of dynamic voltage restorer would also be deteriorated due to the power quality disturbances. This would lead to the stability problem of power supply in the power grid. Therefore, the effective analysis for the control characteristics of dynamic voltage restorer and application of synchronous detection technique robust to power quality interference would enhance the safety and stability of renewable energy. However, the present commercial products mainly provide the dynamic voltage compensation ability based on the assumption that the system voltage is nominal sinusoidal. When the power quality disturbances are present, no technique can accurately detection the fundamental component and complete the correct voltage compensation. From above, this project would focus on (1) enhancement of detection accuracy for the fundamental signal to calculate the reference compensation signal and reduce the synchronous detection errors in the traditional algorithms; (2) reduction of computational complexity and enhancement of real-time control for the dynamic voltage restorer with the short-duration window for the fundamental signal analysis; (3) accurate detection of reference compensation signal under thepower quality interference to prevent the tripping of renewable energy when the short-time fault is present; (4) flexible customization of intelligent controller design to rapidly implement the compensation control system and adjust the parameters based on the field situation and international standards.