Analysis of the Maximum HVDC Infeed Power Based on Power System Minimum Inertia Constraint

With the increase of the proportion of HVDC transmission, some synchronous generators are replaced by HVDC, which leads to the decrease of the inertia level of the receiving-end grid and threatens the frequency stability of the power grid. In order to study the maximum infeed power of HVDC, firstly this paper derives the dynamic response expression of the power grid frequency including the inertia response and the primary frequency response of the synchronous generator. Secondly, on the premise of avoiding under frequency load shedding (UFLS), the minimum inertia required in the case of N-1 is solved based on the frequency dynamic response expression. Thirdly, taking the minimum inertia as a constraint, the maximum infeed power of HVDC transmission is estimated. Finally, the effectiveness of the method is verified in the IEEE 39-bus system.