This paper presents a reliable power supply island scheme

which has the advantages of not only providing highly reliable and high quality power

but also promoting the intelligence of distribution network. Taking the reliable power supply island with double sources and double loads as an example

this paper firstly proposes the topology of the scheme

expounds the control strategy and establishes its mathematical model. Theoretical analysis shows that except for value setting of the controllable quantity

no switching control strategy is required when reliable power supply island operates in different working conditions. Secondly

based on the control strategy

this paper designs the specific control mode for every converter in detail. Finally

a simulation model is built to test the realizability of reliable power supply island under different working conditions. Simulation results also show that the scheme can guarantee supply of highly reliable and high quality power.