| "Three North" area owns rich wind power resources.As a result,the wind power installation capacity increases rapidly.However,the imperfect power grid structure and the CHP units’ "thermo-electric coupling" constraints lead to serious phenomenon of wind power curtailment.The existing references only analyze the mechanism of wind power curtailment and the consumption measures in CHP system from single aspect,which is the power network safety or CHP units’ "thermo-electric coupling" constraints.Therefore,these strategies are only applicable to the curtailed wind power caused by single reason.This dissertation analyzes wind power curtailment mechanism from both perspectives,which are power transmission line limitation and "thermo-electric coupling" constraints.It researches the influence of power grid operation mode on wind power consumption.Also,it carries out researches from the perspective of source-grid collaboration and source-grid-load coordination in order to consume wind power,which is caused by both reasons.Firstly,this paper studies the influence of power grid operation mode on wind power consumption in CHP system.It analyzes the wind power curtailment mechanism affected by power grid operation mode in CHP system.Assessment indicators for wind curtailment reasons are raised.An optimal dispatch model of CHP system is established.It includes power and heat network security constraints,units’ operating states,power network topological changes and the penalty cost of electric& heat load loss.Case study shows the CHP unit "thermo-electric coupling" constraints and power network safety constraints may alternately or simultaneously cause wind power curtailment in dispatching period.The unit startup plan and the power network topology all affect the reasons,the periods and the rate of wind power curtailment.In addition,the changes of grid operation mode due to quit equipment in different periods also affect the wind power curtailment rate.Meanwhile,the amount can be reduced by prioritized starting standby units in plant which occurs unit shutdown,and putting in standby transmission lines near the wind farm.Then,dispatching model of wind power consumption by source-grid collaboration in CHP system is raised.It proposes an improved DC power flow algorithm considering line reconstruction.Based on the algorithm,a source-grid collaboration dispatch model including unit combination and line reconstruction in CHP system is established.Case study shows through reasonable choice or combination of three strategies,which are unit output optimization,unit combination and line reconstruction,the model can reduce curtailed wind power caused by those two reasons according to the amount and the reason of wind power curtailment.And it can achieve maximum wind power consumption without new investment.Finally,dispatching model of wind power consumption by source-grid-load coordination in CHP system is raised.It analyses the mechanism of wind power consumption caused by two reasons through electric boiler.It proposes TEC & PNS wind power curtailment flags,and the flags are introduced to electric boiler control strategy.The source-grid-load coordination dispatch model in CHP system is established.Case study shows the flags can identify wind power curtailment status correctly.The model can in turn dispatch the low-cost,good-consumption schedulable resources according to the amount and the reason of wind power curtailment.It can consume the curtailed wind power further caused by both reasons. |
