When master-slave microgrid is transfered from grid-connected mode to islanding mode

the control mode of master inverter changes from current control to voltage control. But the controller structrue must be transferred and voltage is unable to be controlled in islanding detection period. To solve the above problems

a control strategy based on collaborative control of voltage and current is proposed

in which load voltage is controlled by voltage controller during the whole working process. In the grid-connected mode

voltage controller keeps power balance with microgrid load and makes a stable output

meanwhile an additional current controller is introduced to regulate output current and keep power balance between microgrid and the grid. In islanding mode

the current controller quits from working

and the load voltage is still maintained by voltage controller. So the power can be balanced and the output of controller is continuous. Besides

the control mode has been transferred to voltage control mode seamlessly. According to the described collaborative control of voltage and current

a voltage controller and a current controller are designed. Finally

simulations using Simulink and experiments show that the collaborative control of voltage and current can realize seamless transfer of microgrid.