A Feeder Power Flow Control Based On The Priority Of Generation Cost For The Islanded Microgrid

Microgrid has become an important platform for distributed generation(DG).Due to the particularity of different types of DG uinits in low carbon index and generation cost,the research on optimal economic operation of microgrid has gradually attracted attention.And the power flow distribution of microgrid has important influence on the economic optimization of system.Based on the generation cost of different DG uinits,the paper has contrasted operation cost of low voltage microgrid under different droop control strategies,and analyzed the power loss of unit output power control mode and feeder power flow control mode.Additionally,based on the idea of the optimal power flow control of microgrid,the economy of the system can be improved by setting the objective function of the cost and constraint conditions.Aimed at reducing the generation cost and feeder loss,the research on improving the economic efficiency of islanded microgrid is conducted.In the low voltage microgrid,the traditional droop control strategy distributes loads just according to the rated capacity of DG uinits,which does not consider the generation cost of DG.The generation cost is combined to the nonlinear droop control strategy through weighting factor,but the determination scheme of weighting factor value is not proposed and the loss of no-load is ignored in the method.With considering these disadvantages,the control method of feeder power flow based on the priority of generation cost for islanded microgrid is put forward in the paper,which combines the advantages of the linear droop control strategy,the nonlinear droop control strategy and the feeder power control strategy.Based on reducing the feeder loss,frequency fluctuation and generation cost,the optimized operation of microgrid is implemented by the control strategy.The strategy makes full use of the new energy distributed generation to achieve the DG unit putting into operation according to the load size.And in order to reduce the power loss of the feeder in the low voltage microgrid,the feeder power flow control strategy is adopted to realize the local load near distributed.Thus the economic operation through the inverter control strategy has been realized in the low voltage microgrid system.Based on accomplishing the simulation and analysis by the MATLAB/Simulink,theexperiment platform is built and a series of experiments are completed,which include the traditional droop control strategy,the nonlinear droop control strategy based on the priority of generation cost,the feeder power flow control strategy and the feeder power flow control strategy based on the priority of generation cost.The experimental results present that the generation cost and feeder loss are reduced significantly by the control strategy of feeder power flow based on the priority of generation cost under the premise of ensuring the system stable operation.