Research On Flexible Control Strategy Of Integrated Energy System Considering Multiple Objectives

Integrated energy system(IES)is a multi-energy coupling system that combines information flow,energy flow and business flow.It can make the coordinated control of the power system,natural gas system and thermal system,which is of vital significance in promoting the consumption of renewable energy,improving the utilization efficiency of clean energy,transforming energy infrastructure and maintaining the safe operation of energy supply systems.The development in energy and information technologies accelerates the transformation of traditional discrete energy system into integrated energy system,where electricity,gas and heat dispatch and control in a highly coupled and coordinated manner.IES promoting and replicating at the terminal of distribution grid provides a new idea for optimal operation and emergency control strategies of the traditional distribution grid.This paper mainly studies the flexible control strategy of IES considering multiple objectives based on smart building level,agent level and distribution grid level.The main work of this paper is as follows:(1)Mathematical models of smart building component-level integrated energy devices are firstly built.Then,a detailed dynamic characteristic model of the smart building IES is developed considering the source-load dual characteristics and multi-energy coupling characteristics.Futhermore,a virtual energy storage model considering the characteristics of power,power change rate,energy,etc.are proposed to describe the external energy characteristics of IES.(2)A three-layer building-agent-distribution interaction architecture is constructed based on the multi-agent technology.Based on building virtual energy storage model(VESM),a quantitative analysis method of a single agent’s VESM is developed considering the multi-building power exchange,grid-connected energy storage,micro gas turbine and other resources controlled by the agent.On the basis of this,a multiagent-based IES coordinated control strategy of energy consumption is further proposed.(3)A hierarchical scheduling optimization model of IES with multiple objectives is proposed,which considers the differences in response time characteristics of different energy sources and incorporates multi-objective operational constraints such as environmental protection,energy consumption,and reliability constraints.The lowest total system operating cost is set as the objective function to implement day-ahead optimization and intra-day correction so as to reasonably arrange the output plan and output adjustment of each controllable unit.(4)A multiagent-based emergency control scheme is proposed for several IESs to participate in the distribution grid power shortage control.Based on the determinate optimum operation state of IES,the adjustable power potential of each IES is evaluated and uploaded with regulation capacity and regulation rate considered.Then,the response power demand of each IES proportionally to the potential is calculated and delivered.Finally,an emergency control scheme and process considering the priority and capacity of controllable devices is formulated to compensate for the power shortage.