Cooperative adaptive inertial control for PV and energy storage units with multiple constraints

Abstract

Virtual synchronous generator (VSG) control for increasing inverter-based sources is characterized by attractive features such as supporting virtual inertia, flexible design, and enhancing frequency stability. However, the performance and status of each VSG unit lead to differences in the inertial support capabilities. This paper investigates a cooperative adaptive inertial control method for multiple photovoltaic and energy storage units (PV-ESUs) to improve system inertia distribution capability during transient events. The frequency discrimination of power disturbances is realized through filters, and the operating ranges of different types of energy storage devices are determined. For the coordination problem with each VSG unit under low-frequency disturbance. The coordination controller, which regulates virtual inertia values by using technique for order preference by similarity to ideal solution (TOPSIS) evaluation algorithm, is proposed to adaptively adjust the inertial output capability of each VSG unit and provide optimized dynamic frequency support to the grid. The state of charge (SOC) of energy storage, converter adjustable capacity, the maximum adjustable output power of the system per unit time, and other influence factors are considered as actual multiple operation constraints. Finally, the effectiveness and engineering application value of the proposed control strategy is verified by the hardware-in-the-loop (HIL) experimental test platform.