Study Of New Generation Of EMS Based On Three Dimensions Coordination

With the power grid interconnection, large-capacity, ultra or extra-high voltage power equipments and new electric components have been linked together in ultra-large-scale grid, a super power grid is coming into being. Higher and more requirement is put forward to energy management system (EMS). Part of requirement is associated with the technical characteristics of grid, the performance of super grid is very complex because of mutual constraints and mutual influence of electric components, EMS is needed to analyze and control grid accuratly. Other requirement is associated with the non-technical characteristics of the power grid itself, EMS must meet the need of hierarchical dispatching system, power market and energy conservation, etc. The issues in technique aspect, management aspect, market aspect and policy aspect are intertwined, new ideas, new analysis and control technology are needed to apply in new generation of EMS.The complexity of super grid is showed in three dimensions of space, time and control objective, new generation of EMS must be compatible with it. New generation of EMS is an online analysis, early warning, automatic operation and intelligent decision-making system, which can adapt well to the characteristics of grid in space, time and objective dimensions, is a real-time closed-loop control system based on global optimization.Study work is executed from some spots to the whole situation in the paper. For new idea and solution to develop new generation of EMS, several research hotspots and emphases in constructing new generation of EMS are discussed and studied. The main research contents and conclusions are as follows:1) Power system modelling research based on CIM. By studying the topology model, equipment model, measurement model, control model and protection model in CIM and their way of information acquisition, in addition to the mechanical and electrical transient analysis, we know CIM has had the practical ability in the network analysis. If CIM can be consummated and supplemented in the practical application, simultaneously, defects in the control model and the ambiguous question can be solved properly, CIM model ought to be able to adapt the higher request of network analysis application.2) Study of application software transplant based on CIS. Transplant of short-circuit current software based on CIS is elaborated, plug and play between isomerous application softwares and platforms can be achieved by CIS interface, application software's independence and versatility can be guaranteed, software resource can be protected effectively. For real-time check of circuit breakers' interrupting capacity, the existing short-circuit current algorithm has been improved, re-numeration and re-optimization of nodes is avoided and computation speed is improved effectively by parallelling branch of negative impedance.3) Study of information interaction between different EMS systems based on IEC 61970 standard. The online external network auto-equivalence software as an example is introduced to explain how the information of EMSs in defferent dispatching centers is interacted based on the IEC 61970 standard. By the test of equivalent effect, information interaction between EMSs can improve the computational accuracy of network analysis software effectively.4) Study of the closed-loop active power automatic control system based on the coordination control in three dimensions of time, space and control objective. In time dimension, frequency regulation, AGC, the real-time dispatching and energy conservation dispatching at present as a research hotspot constitute the coordination control in time series; In space dimension, grid dispatching center, provincial dispatching center, power plants and generators constitute coordination control; In objective dimension, grid's technical characteristics such as frequency quality, balance between generation and load, security constraint and non-technical characteristics such as power market, energy conservation dispatching and so on are interweaved, the closed-loop active power control must adapt to all of the characteristics, coordination control is constituted based on the multi-objective. AGC control strategy based on CPS and real-time dispatch algorithm based on ultra short-term load forecast have been studied, the research results has been applied in practice, the remarkable effect has been obtained.5) Study of the closed-loop reactive power (voltage) automatic control system based on the coordination control in three dimensions of time, space and control objective. In time dimension, AVC system of defferent level should choose appropriate control cycle, the difference of discrete control device and continual control device in time characteristic makes discrete equipment's control should combine the results of short-term and ultra short-term load forecast; In space dimension, appropriate coordination control variables among grid dispatching center, provincial dispatching center and regional dispatching center or between AVC primary station and AVC terminals in power plants are chosen to constitute coordination control; In objective dimension, mathematical model of reactive power optimization as well as the coordination between static voltage stabilization and AVC constitute coordination control.6) Study of joint anti-accident exercise based on DTS systems' interconnection. All kinds of joint anti-accident exercise's modes are introduced and compared in this paper, the mode based on multistage DTS systems' interconnection has a lot of advantage as well as feasibility in practice, which can be achieved by the information interaction in time dimension and space dimension. In time dimension, information interaction between DTS systems is needed before, in and after joint anti-accident exercise; In space dimension, joint anti-accident exercise is achieved by the information interaction among three level dispatching centers (province, region and county), exercise between province and region is achieved by DTS systems' information interaction, exercise between region and county is achieved by WEB visit.