A　novel　hybrid　control　strategy　for　energy　storage　(ES)　is　applied　in　accordance　to　the　recommendations　by　the　IEEE　Std.　1676.　The　strategy　mainly　consists　of　the　model　predictive　controller　(MPC),　two-degree　of　freedom　algorithm　and　modified　droop　control.　In　inverter　control　layer,　MPC　and　two-degree　of　freedom　algorithm　are　adopted　to　construct　a　generalized　controller　to　enable　ES　operate　in　microgrid　grid-connected　and　islanded　operation　modes　with　a　single　control　structure,　motivating　the　smooth　transition　between　microgrid　operating　modes.　And　MPC　and　two-degree　of　freedom　algorithm　are　used　in　the　control　layer＇s　current　inner　loop　and　voltage　outer　loop,　respectively.　Comparing　with　the　traditional　double　loop　control　from　the　perspective　of　structure,　with　the　novel　strategy　the　control　layer＇s　current　inner　loop　is　without　pulse　width　modulation　(PWM)　and　only　a　single　proportional-integral　(PI)　controller　is　applied　in　its　voltage　outer　loop,　so　that　ES＇s　robust　performance　can　be　enhanced.　And　because　of　the　high　frequency　inverter＇s　equivalent　transfer　function　with　the　smaller　time　constant,　MPC＇s　transfer　function　approximated　as　being　unitary.　Therefore,　when　the　two-degree　of　freedom　algorithm　construct　the　inverse　model　for　the　controlled　object　in　control　layer＇s　voltage　outer　loop,　from　the　application　layer　perspective,　the　control　layer　can　be　recognized　as　unity　gain.　Thus,　the　control　layer＇s　harmful　disturbances　associated　with　the　operation　mode　transitions　can　be　removed.　In　the　application　layer,　through　adding　decoupling　inductance　and　introducing　microgrid＇s　voltage　and　angular　frequency　feedforward　compensations　to　carry　out　PQ　and　modified　droop　controls,　the　grid-connected　and　island　control　targets　of　ES　application　layer　can　be　realized.　In　particular,　when　microgrid　operation　mode　is　switched　to　island,　with　the　help　of　modified　droop　control,　microgrid＇s　voltage　and　frequency　can　be　quickly　restored　to　standard　values.　Through　the　theoretical　derivation　and　simulation　results,　it　can　be　proved　that　under　microgrid＇s　plan　or　non-plan　operation　mode　switching,　the　proposed　method　can　not　only　can　not　only　implement　the　microgrid　smooth　switching,　but　also　strengthen　its　transient　performance.　©　2013　IEEE.