Study On Economic Dispatich And Benefit Analysis Of Regional Power System Considering Deep-peak Regulation

As the stochastic uncertainty of new energy output and the unbalanced distribution of power source and load,the peak load pressure of regional power system is increasing.It is a feasible method to solve the problem by using peaking capability of thermal power units for peak shaving.However,nowadays the thermal power plants are unwilling to work in deep-peaking state,because deep-peak regulation brings poor economic benefit and high pollution emission.In this paper,deep-peak benefit of power units has been analyzed from various aspects:Firstly,the peaking capacity and peak process of thermal units and gas units was analyzed,from the aspects of unit operating state,combustion medium and emission product.Focused on different deep-peaking methods of thermal unit and gas unit,the full process peaking cost of the power unit was proposed.Secondly,in simulation of an actual power grid,generation cost of thermal units under different scheduling strategies was shown.Simulation results show that increasing peak-shaving depth of peak-shaving units appropriately,to 55%of rated capacity,can increase peak-shaving benefit,but further increase of peak-shaving depth will reduce benefit of whole system gradually.After increasing peak-shaving depth to 65%of rated capacity,the benefit is lower than that in basic peak-shaving stage.The results can provide theoretical reference for benefit analysis of deep peak-shaving auxiliary service of thermal power units.Finally,to minimize generation cost of the system,the economic dispatching model of the power system in consideration of gas unit's additional cost was established.Energy efficiency was used to assess the economy and feasibility of gas unit participating in deep peak regulation,from the economic,social and environmental perspective.Simulation results show that,in non-heating period,the gas unit should operate in deep peak regulation state.The economic dispatching mechanism should consider the additional cost of the gas unit to improve the energy efficiency of the power system.