Study On Optimal Scheduling Model Of Power System Considering Peak Load Regulation Of Nuclear Power Plant

At present,nuclear power of China is in a period of rapid development.Considering the fact that the distribution of nuclear power plants is concentrated in coastal areas near the load center,the base-load operation mode of nuclear power units at full power brings tremendous peaking pressure to the power system.Coupled with the large-scale wind power integrated to grid and the continuous increase of the peak-valley difference of load,the demand of nuclear power participating in peak load regulation is increasingly urgent.Although modern nuclear power units are designed with the capability of load following,peak load regulation with participation of nuclear power are rarely considered in optimal scheduling of power system.Corresponding researches such as peaking cost calculation,safety constraints and risk assessments of nuclear power have not been conducted deeply.Therefore,it is of great theoretical value and practical application significance to study the related issues of power system optimization scheduling considering nuclear power peak load regulation.Based on reviewing a large number of domestic and foreign literatures,this dissertation combines several research projects to deeply and systematically study the cost calculation,the operation mode of load following,the optimal scheduling of joint operation and the risk assessment of nuclear power participating in peak load regulation.The main work is as follows:The research status and progress of optimal scheduling of power system,peak load regulation with participation of nuclear power and corresponding economic and safety evaluation were summarized.The load following characteristics of nuclear power are analyzed from three aspects:the typical power control mode,the power regulation performance and the load following operation mode.Considering the economic influence of peak load regulation on operation of nuclear power,a calculation and analysis method for the related cost was proposed.With the establishment of the nuclear power operation index system and the comprehensive application of the life cycle theory,a calculation method of the leveling power generation cost with consideration of nuclear power peak load regulation was put forward.Aiming at the key links of nuclear fuel cycle affected by peak load regulation,a method for calculating the additional fuel and spent fuel treatment cost was proposed to realize comprehensive quantification of peaking cost.According to the historical operating data,the leveling power generation costs and peaking costs of nuclear power were practically calculated.The benefits of nuclear power participating in peak load regulation was analyzed through the peaking cost curve,laying the foundation for operation strategy research with consideration of nuclear power peak load regulation.Comprehensively considering the operating economy and safety requriements of peak load regulation,an optimal model of nuclear power units in load following operation was established.The model determines the basic operation inode according to the fuel life req,uirements and the annual planning arrangement of load following.The optimization target was set to maximize the operation benefit of the nuclear power plant with consideration of net benefit of electricity sale,cost of peak load regulation and penalty cost of output plan deviation.Targeting at the safety requirements,the operating state variables of nuclear power were proposed and the constraints including basic constraints,continuous operating time constraints with constant power and state shifting constraints with power up/down were established to satisfy the output characteristics of peak load regulation.The effectiveness of the model was verified with practical examples and the influences of the peak-valley electricity price,the punishment force of output deviation and the standard of compensation were analyzed.A model of economic dispatch with joint operation of thermal power-nuclear power-pump storage hydro was established.The objective function is to minimization the total operating cost including fuel cost,start-stop cost and the peak load regulation cost.Considering the conventional constraints of thermal power and pumped storage hydro,the regulation characteristics of nuclear power mode was analyzed from the time,the depth and the speed of peak load regulation.Combining with operating state variables,the output constraints of nuclear power with consideration of the flexibility of peaking operation were proposed.The validity of the established model was verified by example analysis and the strategies of peak load regulation with different operation mode of nuclear power are compared.The effects of spin reserve requirements,deep peak regulation capacity of thermal power and peaking cost on the strategy of peak load regulation were analyzed.Considering the impact of peak load regulation on the safe operation of nuclear power,an optimal scheduling model of power system which took the peaking risk into account was established.Based on the mechanism analysis of peak load regulation causing outage failure,the risk index system of nuclear power peak load regulation xwas proposed.According to the security risk theory,the risk assessment method and model were put forward to achieve the calculation and analysis of safety risk increment of peak load regulation of nuclear power.Incorporating the peaking risk into the operating cost of power system in the form of peaking safety cost,an optimal scheduling model with multi-source joint operation was established with consideration of the randomness and volatility of wind power.The validity of model is verified through a practical example and the influences of the safety value of nuclear power is analyzed.