Abstract：Rotational inertia of power system is reduced because of the large number of integrated distributed generators. As an effective way to solve this problem, virtual synchronous generator (VSG) technology has significant advantages in flexible adjustment of virtual inertia. However, the flexibility of the adjustment must meet various constraints. In this paper, a multi-constrained flexible virtual inertia (M-FVI) control method is proposed in combination with the actual working conditions. This method considers the limit working state of the energy storage unit, the system frequency change rate, the inverter capacity and the power adjustable amount of the system in unit time. The four-terminal system model with photovoltaic energy storage VSG unit is built, and the small-signal model of the system is established. The influence of key parameters on the system stability is analyzed by root locus method. The method and principle need to be followed for the design of control parameters are given. Finally, the effectiveness and practicability of the multi-constrained virtual inertial control strategy are verified by the hardware-in-the-loop experimental platform.
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2019, Vol. 34 
