| Smart district Micro-grid can be defined as a low voltage distribution networks clustered distributed power sources, storage devices and loads that is serciced by a distribution network and can operate either grid-connected or isolated modes. As the access terminal of new generation technologies and methods, smart district micro-grid needs to realize the energy coordination between distributed power sources, energy storage unit, loads and distribution network, ensure system reliable and economic power supply, which require the feasible operation and control strategy of smart district micro-grid.Economic dispatching for smart district micro-grid is an in portant aspect at the operation control stage, it employ economic generation scheduling to coordinate the output of the distributed power sources as well as to meet the given load level, then minimize the total operation cost of smart district micro-grid; Frequency regulation for smart district micro-grid is an important guarantee for the realization of system safe and economic operation, it through control the output of frequency modulation unit to meet the changing demand, maintain the frequency constant of smart district micro-grid, and ensure the economic and stable operation of smart district micro-grid.This article focuses on economic dispatch and frequency regulation of distributed generation and smart district micro-grid, the detailed research contents are summarized as follows:(1) The paper firstly analyzing former researches of smart district micro-grid at home and abroad, give an integrated design for smart district micro-grid on the basis of technical characteristics, geographical environment and weather conditions, and introduced the detail functions of main composition, then established the mathematical models of the residential micro-grid, which consists models of wind turbine(WT), photovoltaic array(PV), battery storage(BAT), micro turbine(MT), and electric vehicle(EV).(2)Aiming at local climate conditions, the distributed energy data were processed. Based on priority mode of distributed power sources and system operation mode, four typical control strategies of smart district micro-grid are developed. From the optimization objectives of production cost, transaction cost, penalty cost and emission cost, established the economic dispatch model of residential micro-grid with distributed power sources embedded, and then use an improved particle swarm optimization method to solve the dispatch model. In the study case, compare the optimization results under different optimization model and different control strategies. Case study results indicate the smart district micro-grid has a greater potential for grid-connected mode.(3) In addition, research on frequency regulation for smart district micro-grid operating in islanded mode is of great important. Aim at micro-sources of good ability in frequency regulation, control strategy of electric vehicle (EV) participate in system frequency regulation is proposed. Designed the dynamic model consider EV participating in system frequency regulation, and established large-scale EVs engagement model in system frequency regulation, achieved the charging/discharging control of large-scale EVs; Consider the Dynamic characteristics of DFIQ designed frequency control link, achieved the control of rotor kinetic energy and pitch angle, realized the power output of DFIG response to system frequency changes. In view of islanded mode, a dynamic model considering EVs participating in frequency regulation is established. Through simulation demonstrates that the proposed frequency regulation method improved the performance of the system and improved the ability to withstand loads disturbance. |
PDF Full Text Request