| As the economy of China enters into the new normal state,power demand slows down,the space for electricity growth is much lower than expected and the number of hours of utilization of coal has declined year by year.At the same time,there is a great gap between the energy consumption of power grid peak shaving and the international advanced level.At present,our country’s energy consumption of power system peak is high.The function and structure of the power grid peak shaving is still relatively single,mainly due to the low load peak shaving of the coal-fired units.The proportion of distributed renewable energy in grid which participates in peak shaving is low.It is urgent to improve the peaked energy efficiency.This paper,according to the relevant requirements of intelligent energy construction ’’several opinions on further deepening the reform of electric power system’’,and the ’’Internet +’’,systematically analyzes the key factors of influence of supply and demand side peak shaving regulation on energy efficiency of power system as well as the ways and methods to improve energy efficiency of the system.This paper has made some theoretical,engineering practical and valuable research results in achieving complementary optimization of multi-type energy,making the system to maximize the utilization of renewable energy and clean energy and increasing the energy efficiency of the system in peak load shaving.In this paper,the main research contents and innovation include:(1)Optimization of joint peak shaving of two-shift coal electricity and pumped storage.The denitration system is usually not normally used which has become an urgent problem to be solved in green power dispatching in regional power grid during the period of low load peak shaving of coal-fired units.In this paper,based on the qualitative analysis of the influence of pumped storage and coal-fired units on the denitrification energy efficiency,an optimal model for regional peak regional system peak shaving based on two-shift coal electricity and pumped storage is established.Through the establishment of an optimal combined peak load shaving model with pumped storage and coal-fired units considering pollutant treatment and the cost of emission.Compared with the system load peak shaving before optimization,the optimized method is based on the mode of joint peaking with pumped storage and two-shift coal-fired units.During a daily peak load cycle,denitrification,desulfurization,dust disposal costs,the cost of carbon emissions and the total cost of power generation are reduced.As the operating parameters of low load peaking has a greater impact on denitrification system energy consumption,the impact on cost is more obvious.In this paper,the optimal joint peak load shaving model with pumped storage and coal-fired units considering pollutant treatment and the cost of emission has improved the economic and environmental benefits of regional power grid,proved the rationality and practicability of the model and method as well as the accessibility of the pollutant ultra-low emission of regional system peaking.(2)Analysis on energy conservation of joint peak shaving of two-shift coal electricity,pumped storage and wind-light-water power.This paper,based on the operational characteristics of hydropower units,wind power,photovoltaic power generation,analyzes the emission reduction mechanism and calculation methods associated with the joint peak load shaving operation of coal-fired power generating units.On the basis of determining the priority of power generation in renewable energy generation units and heating units in heating period,this paper analyzes the potential of energy conservation and emission reduction of each regional system based on the electricity displacement.In addition,the co-operation of coal-fired power generation and renewable energy power generation(hydropower,wind power,photovoltaic power generation),need to take full account of the alternative benefits of clean energy,the load balance benefits and peak adjustment benefits of coal-fired generating units,as well as influences of generating units and time distribution,should play a supporting role in coal-fired generating units.(3)Quantitative analysis on influence of supply and demand-side peaking on energy efficiency of system peaking.Based on the influence of supply and demand-side peaking on energy efficiency of system peak shaving,as well as the potential of system absorbing renewable energy power generation,this paper has taken a regional power system as an example to simulate and has proved that the supply side is optimized by the two-shift system of coal-fired units,which can greatly improve the operation load rate of coal-fired generating units and system energy efficiency.on the basis of coal-fired generating units using operation mode of two shift peak,participation of hydropower units peak shaving in the system will increase the flexibility of system operation as well as the potential of the system to absorb the potential of renewable energy power generation,thereby improving the system energy efficiency.Under the condition of ensuring that wind power,photovoltaic power generation priority access to network,the optimal joint peak shaving of coal-fired generating units and hydropower generating units without additional cost,only need to change the peak shaving mode.(4)Design of evaluation method of energy efficiency of supply and demand-side peak shaving regulation.It’need to establish the peak load regulation energy efficiency evaluation system based on entropy weight attribute recognition.The evaluation system,using the system coal consumption,coal consumption of coal power units,grid-connected coefficient of renewable energy,rate of abandoned air and load rate of power network as the five energy efficiency evaluation indicators of the system peak shaving regulation scheme and combining the model of attribute recognition and the theory of information entropy in information theory,has established the attribute space of the peak shaving scheme and perform an orderly segmentation.Then the entropy method is used to determine the objective weight range of attributes and calculate the attribute measure of scheme for peak shaving with weighted sums.Finally,according to the confidence criterion,we can determine the virtues or defect of the peak regulation program to ensure the objectivity and accuracy of the results of evaluation.Taking a regional power grid in the north as an example,this paper has selected a typical day as an evaluation object and has applied the peak regulation energy efficiency evalution system based on entropy attribute recognition to evaluate.Through the comparison and summary it is found that the economy of two-shift peak regulation is better than the low load peak shaving and it is proved that the peak shaving comprehensive evaluation method based on entropy weight and model of attribute recognition is effective in decision of system peak shaving.The evaluation method can objectively evaluate the virtues or defect degree and quantify the problem studied to show the feasibility and practicability of the evaluation method.(5)This paper put forward countermeasures and suggestions on improvment of supply and demand-side peak shaving.On the basis of analysis on system energy efficiency evaluation,in the respect of ancillary services like complementary operation of supply-side,the co-operation of supply-side and demand-side,the peak shaving mode as well as reserve capacity,this paper has analyzed the problem of power structure and load structure and put forward the relevant countermeasure suggestions from the perspective of the optimal operation of the system peak shaving,system energy efficiency evaluation and the government supervision.In this paper,the analysis on the influence of supply and demand-side peak shaving mode on system energy efficiency has provided valuable reference program to achieve the target of energy conservation and emission reduction for the current regional power system peak shaving.At the same time it can provide theoretical guidance for relevant countermeasures.This analysis not only has cacdemic value,but also has the practical value to improve the power system peak shaving mode and promote the harmonious development of low carbon society and electric power industry. |
