Research On Scheduling Strategy And Model Of Renewable Energy Integration Involving Active Load

With the energy crisis and environment problem becoming more and more attention, the development of renewable energy has become a hot spot, however, due to the randomness and intermittency of renewable energy, renewable energy poses great challenges on power system operation. The issue of renewable energy integration is increasingly serious. Active load is important interactive resources under smart grid paradigm. Active load is gradually becoming an effective approach to integrate renewable energy as it could be flexibly deployed and follow the system requirement immediately. Due to micro-grid controllable on the macroscopic, uncontrolled renewable energy connects to the micro-grid has become an effective way to integrate renewable energy.Research on scheduling strategies and model of active load for renewable energy integration is discussed in this paper. Firstly, this paper reviews the development of micro-grid at home and abroad, the research status of active load and the scheduling method consider renewable energy integration; Secondly, this paper introduces dispatching mode considering the active load, and analyzes the feasibility of active load for renewable energy integration; To consider in the form of distributed renewable energy connecting to the micro-gird, this paper puts forward the independent micro-grid day-ahead scheduling plan model considering the active load; Considering the uncertainty of renewable energy and interactive model between micro-grids and the distribution network, this paper set up the bi-level programming model of the distribution network and micro-grids. The main contents are organized as follows.(1) The basic theory of micro-grid is introduced, including the micro grid basic structure, operation mode, the power supply model, control mode, etc. And this paper analyzes the active load model and the resources characteristics, the content includes the electric vehicle charging and discharging module and incentive-based demand response module, additional, this paper analyzes the feasibility of active load for renewable energy integration, the research content lays the foundation for subsequent paper.(2) This paper puts forward the day-ahead scheduling framework of the independent micro-grid, the day-ahead scheduling plan model of the independent micro-grid has established, the model covers the electric vehicle unordered charging model, the electric vehicle orderly charging and discharging model and the economic scheduling model of micro-grid. Case study indicated that the electric vehicle orderly charging and discharging can effectively smooth net load curve, reduce system requirements about climb and peak shaving, improve operating efficiency of power system, additional, active load resources to participate in the incentive-based demand response for the system to provide extra spare capacity, which can effectively reduce the cutting load and renewable energy, improve the reliability of the system operation and the integration rate of renewable energy.(3) This paper studies on the interactive operating mode between micro-grids and distribution network, puts forward the interactive scheduling framework between micro-grids and the distribution network. With micro-grid coordinate with the interests of the distribution network into consideration, using bi-level programming, this paper has established the double coordinate scheduling model between micro-grids and power distribution network, considering the electric vehicle charging and discharging in order and active load as backup resources of power system, and with electricity price as a lever, the model coordinates the interests distribution between micro-grids and power distribution network, and considering the uncertainty of renewable energy, this paper introduces chance constraints to spinning reserve constraints in the model. Case study indicated that by optimizing the electricity price, the model adjusts the interests between distribution network and micro-grids, and achieves their optimal results, and improves the integration rate of renewable energy, in addition, with the improvement of spinning reserve constraint in the confidence level, it increases spare capacity to bring down the intermittent of distributed renewable energy sources and uncertainty of load, reliability of the micro-grid system is improved, and the cost of the micro-grid also increases accordingly. This method can be used for coordinated operation of micro-grid and grid.