Research On Optimal Operation And Control Techniques Of Virtual Power Plant For Active Distribution Network

With the increasing intensification of energy crisis and environmental pollution problems, the development of new renewable energy has become the research hotspot recently. Distributed generation resources provide effective supports for the traditional power system, but it has obvious shortcomings, such as poor controllability, small capacity and dispersion. To better integrate these distributed generation resources, domestic and foreign experts and scholars have proposed the concept of virtual power plant (VPP). At the same time, considering the increasing demand side resources and the access of distributed generation to the power distribution network in the form of independent power supply or microgrid, the traditional power distribution network will have many problems, for instance, the power flow will change from one-way to two-way, the line capacity cannot meet the demand and the operation and management method cannot adapt to the new environment. Therefore, domestic and foreign experts and scholars propose the concept of active distribution network (ADN)This paper is based on the background of the rapidly development of the distributed energy resouces,regarding this as the cutting point,and has systematic studied on the internal coordinative optimization strategy of the virtual power plant and initiative management technique under muti-sources grid enviroment.The main content of this dissertation is as follows:(1) Due to its inherent uncertainty and cannot be forecasted easily, wind power plants are often unable to participate in electricity market like the other predictable and controllable generators. Given this, this article using the electric vehicle(EV) energy storage settle the drawback of the wind power. Combined with distributed wind power and electric vehicle be a virtual power plant(VPP), to participate in day-ahead electricity market. By means of modeling the VPP in market form, using the receding horizon optimization, analyzes the profit of the distributed wind power VPP with the EV and the distributed wind power VPP without EV. Aiming at the wastage of the battery, this article shows a compensation scheme for EV. By simulating, the results show that comparing with the VPP without EV, the profit of the VPP with EV gain a significant promotion. And the compensation scheme for EV can motivate the EV owners to take part in the operation of the VPP effectively.(2) To optimize the dispatching cost for distributed energy resources within whole VPP, based on the multi agent structure of VPP an equilibrium dispatching model for DER inside VPP is established. Under the condition of meeting load demand of power system in real time the replicator dynamics algorithm (RDA) is utilized to allocate the DER inside VPP. By means of analyzing the fitness coefficients and dispatchable capacities of different types of DERs, a win-win equilibrium dispatching strategy among multi DERs within VPP is proposed; the smaller the fitness coefficient, namely the lower the invoking cost, the higher opportunity of DER to participate the dispatching is, and if the former is higher, the lower the latter will be. The reasonability and effectiveness of the proposed model and algorithm are validated by simulation results of a VPP containing six generating units. In the solution of DER problem within VPP, the dispatching cost can be controlled more effectively by RDA than traditional market mechanism based VPP methods, besides, RDA possesses the advantages such as convenient to use and easy to expand.(3) Aimed at the market-oriented operation of the active distribution network, the operation model of active distribution network under the market environment was researched, and the objective of market participant of active distribution network was analyzed. Based on the design application of multi-agent system in the active distribution network, the real-time bidding mode of actors of active distribution network was designed with consideration of the line capacity. Through the elaboration to the transformation of bid curve, the equilibrium optimization process of two objectives obtained from the capacity management-based technical indicator and market liquidation price-based economic indicator was analyzed. Through case analysis, the real-time bid operation mode of active distribution network considering the bid curve transformation of capacity management is compared with the active distribution network without this method to effectively limit the occurring of peak values and make the load curve smoother while reducing the line loss rate.