Research Of Thermostatically Controlled Loads In Demand Response Of Community Power System

The scale of the power grid has expanded significantly with the access of large-scale renewable energy under the background of the energy internet,then the stability control of power system is becoming difficult with the complex situations of the grid side and the user side.The emergence of demand response technology provides a new solution for stability control of power system.Household load has been able to respond to the demand of power system to a certain extent,as an important part of household load,thermostatically controlled loads has become a kind of friendly and dispatchable resource for power system.Therefore,it is necessary to study the thermostatically controlled loads' participating in the power system demand response,it is of great significance for the stability control of new power system and the balance between supply and demand.In this paper,the demand side domestic electric water heaters load is taken as research object.The domestic electric water heaters are expected to participate in the community level power system demand response,and the load model,cluster load characteristics and demand response scheduling strategy are studied.Firstly,some loads(air conditioners,refrigerators and electric water heater)can store energy or change the electric consumption time,and the demand response potential is measured from electricity time and price sensitivity by focusing on three indexes: Sheddability,Controllability and acceptability.Then,the modeling theory of load in power system is introduced,including dynamic load modeling and static load modeling;considering the thermodynamic process of temperature control load,the equivalent thermodynamic model of household electric water heater is simplified,and the dynamic and static load model is established;the control structure for electric water heater is designed to participate in the demand response in the community power system.The load characteristics of the cluster electric water heater are simulated by Monte Carlo,and the original operation data is obtained.Finally,the coupling relationship between the operating state of the electric water heater and the active power and frequency fluctuation of the community level power system is established,and the temperature state priority list strategy is proposed.The simulation case verifies the domestic electric water heater's positive effectiveness in community power system demand response,it not only can stabilize the original peak valley difference and frequency fluctuation of the system,but also can buffer the intermittent impact caused by renewable energy's grid-connection grid.In this paper,while the proposed temperature state priority list strategy and corresponding control structure is not good enough to track the power fluctuation when the load changes suddenly,however,it can fully respond to the active and frequency regulation demand in the community power system,it not only can guarantee the comfort of the users,but also can reduce the net loss.The strategy is instructive for the stability control of power system in the new energy environment.