Research On Dynamic Service Restoration Strategy Considering Time Scale For Distribution Network With DGs

With the increasingly high permeability of distributed generation in the distribution network,making use of DG for s ervice restoration is becoming increasingly feasible.Based on that,a dynamic model considering time variation of DGs with time is proposed here and successfully applied to solving the problem of distribution network service restoration with DGs,correcti ng the error that we considered the output of DG as a constant value in the whole recovery period in the previous research.According to the actual situation that real-time output power of different types of DGs keeps changing over time,this paper conside rs extending the time scale to do the multi-period dynamic fault recovery.A minimum summation of load loss with weight coefficient in the restoration period is selected as the main objective function,and the minimum number of switching operations as the secondary objective function.Firstly,the improved binary particle swarm optimization is applied to obtain radial network structure excluding a large number of infeasible solutions.Secondly,the strategy based on optimal recovery path proposed in this paper is used to perform load shedding operation.Lastly,the minimal switch operation problem is solved by enumeration-combination method,then the optimal service restoration switch scheme was eventually obtain ed.The results of example show that the dynamic coordination of the main network and DGs in the distribution network service restoration would achieve a low load loss and practical restoration scheme.On the basis of the model above,this paper takes into account the load changes with time,ultra-short term load forecasting makes the data used by the recovery model more accurate,which makes up for the shortcomings of the previous model which has been calculated with the maximum load of each load node in all periods.In the choice of restoration strategy,taking into account the overall regulation of energy storage,selecting the recovery plan for each recovery period,and to do the service restoration scheme for the next period with the corresponding situation of the remaining energy storage for each recovery plan,thus the optimal solution is obtained.Based on the theory and method proposed in this paper and relying on the background of the project,the distribution network disaster protection decision support system based on GIS is developed.This s ystem is based on GIS interface,loading the load,line,emergency power supply and other modules,the system can achieve disaster early-warning,topology control decision-making,load risk assessment and other functions.The system is achieved based on Fl ex technology and J2 EE application framework and visualized on the basis of building Web GIS geographic information.A common Web architecture is used for open application framework and Flex technology is used for client development.Information integration platform for data exchange is based on IEC 61970/61968 standard Web Service interface.The system has been successfully applied to the scene to provide decision support for the scheduling staff.