Research On Optimal Scheduling Method Of Distribution Network Coordinating Multiple Controllable Resources

In modern distribution network,controllable resources are defined as renewable energy,reactive power compensation equipment,energy storage,flexible load and all other resources that can participate in regulation in distribution network.With the massive access of controllable resources and the diversified development of loads in the distribution network,it makes the optimal scheduling of modern distribution network more difficult.Therefore,it is of great significance for the stable operation of distribution network to study optimal scheduling methods based on the coordination of controllable resources.Firstly,the research background,purpose and significance of distribution network optimization scheduling are described in this paper.The research status of various methods of distribution network optimal scheduling are introduced in detail.Secondly,the types and characteristics of controllable resources are analyzed in the distribution network.Taking distributed generation as an example,this paper analyzes the influence of distributed generation on power flow distribution in distribution network,and studies the power flow calculation method including distributed generation.At present,many research methods analyze the optimization scheduling problem based on the static perspective,without considering the influence of load time variability and uncertainty on the system.Based on the above problem,this paper proposes an improved polynomial load model(ZIP model),to describe the change of load as time scale increases.On this basis,the day-ahead and intraday two-stage optimization method of active and reactive power is proposed,and the objective function including dayahead optimal scheduling cost and intraday real-time optimal scheduling cost is established in this paper.The day-ahead cost includes power purchase cost,distributed power generation cost and standby cost,flexible load standby cost,and day-ahead network loss cost.Intraday scheduling cost mainly includes real-time network loss cost and load loss cost.Finally,a simulation experiment is conducted on the actual power grid to analyze the node voltage,network loss,fluctuation of load and the scheduling cost of day-ahead optimization and intraday optimization.The distribution of node voltage and network loss in four different cases are compared.In this example,the results show that on-load voltage regulator has the most significant effect on voltage regulation.Moreover,the optimal scheduling cost is the least when the on-load regulator,renewable energy and reactive power compensator are involved.This paper takes controllable resources of distribution network as the research object.Considering the time-varying and uncertainty of loads,an improved polynomial load model(ZIP model)is established to describe the actual load characteristics more accurately.Then,a day-ahead and intraday two-stage optimal scheduling method is proposed to effectively regulate voltage and minimize the operation cost of distribution network through coordination of controllable resources.