Advanced EMS and its trial operation in Shanghai power system

Abstract

To meet the demand of high stability, high quality, and low losses of power systems, the advanced energy management system (AEMS) is established and revealed in this bulletin, which has been put into trial operation in Shanghai power system for almost half a year. The AEMS is novel from all aspects covering idea, theory, method, software, and engineering. The essence of AEMS is exercising the hybrid automatic control theory and technology to realize multi-objective optimal closedloop control of power systems. Based on an "event-driven" strategy, the AEMS transforms multi-objective optimal control problems into event identification and elimination by defining the unsatisfactory states of a power system as events. This bulletin concisely presents the theory and main advantages of AEMS, as well as its implementation in Shanghai power system. hybrid automatic control, multi-objective optimization, AEMS, event drivenModern power systems are complex giant ones which spread thousands upon thousands of square miles. Its control and dispatch mainly, up to now, depend on experiences of operators and the corresponding conventional EMS (energy management system) developed in the 1990s [1][2][3] . Restricted by computer technologies and power system control theory at those days, the main function of EMSs was to provide dispatchers with the operating data and information of power systems. Some EMSs might more or less offer advices to dispatchers; however, none of them was in the sense of closed-loop automatic control. The fulfillment of multi-objective optimal control was really the postponed expectation of both the theorists and engineers who dealt with power systems. We have been engaging in the AEMS (advanced energy management system) for eight years and now we have already completed the most important part of this task. The theoretical and relevant software systems have been formed, which are working for the Shanghai power sys-

Multi-level multi-area hybrid automatic voltage control system and its trial operation in Northeast China Grid

“…That is, the command interval of the conventional AVC control scheme is artificially pre-set, not entirely aiming at the actual status of the power system. Whereas the MLMA-HAVC system actually monitors the event occurred in the electrical power system, including all kinds of safety, economy and quality events, and uses the event-driven mechanism [10][11][12][13] to handle different voltage control systems' coordination and multi-objective coordination, in order to achieve the purpose of eliminating events, which means triple indices "safe, high quality and low consumption" can be realized. The event-driven mechanism includes event definition, analysis, dispatch, handling and verification steps.…”

Modern power systems control centers: from EMS to AEMS

“…The AEMS [3] developed on this event-driven idea consists of three modules: the event analysis module, the event handling module and the dispatcher decision-making support module.…”

“…It is becoming evident that it would be impractical for power system operations to satisfy multiobjectives such as security, high quality and economy by means of dispatchers' manual adjustment and control only. The advanced energy management system [2,3] (AEMS) was proposed and developed independently by power system researchers in China. The AEMS can coordinate all controllable resources in power grids in order to achieve multi-objective, near-optimal, and closedloop control of power grid operation.…”

On engineering implementation of the digital power system

“…The HACS can make dynamic quality, security and stability, economy efficiency of power system operation approach their optimal objectives simultaneously. Now, there have been some engineering applications of the HACS in some provincial power grids [5,6] .…”