Yingkun, Z. , Guorui, X. , Siming, W. , Yongzhang, H. (2017). 'Techno-Economic Analysis of Motor-Generator Pair System and Virtual Synchronous Generator for Providing Inertia of Power System'. World Academy of Science, Engineering and Technology, Open Science Index 126, International Journal of Energy and Power Engineering, 11(6), 665 - 669.