The integration and accommodation of the wind and solar energy pose great challenges on today’s power system operation due to the intermittent nature and volatility of the wind and solar resources.High efficient large-scale electrical energy storage is one of the most effective and economical solutions to those problems.After the comprehensive review of the existing storage technologies,this paper proposes an overall design scheme for the Non-supplementary Fired Compressed Air Energy Storage(NFCAES)system,including system design,modeling and efficiency assessment,as well as protection and control.Especially,the design principles of the multistage regenerative,i.e.heat recovery system which is used to fully recycle and utilize the waste heat from compression are provided,so as the overall system efficiency evaluation method.This paper theoretically ascertains the storage decoupling rules in the potential and internal energy of molecular compressed air and reveals the conversion mechanism of gas,heat,power,electricity and other forms of energy.On this basis,a 500-k W physical simulation system of CAES system(TICC-500,Tsinghua-IPCCAS-CEPRI-CAES)is built,which passed a system-wide 420-k W load power generation test with less pollution and zero carbon emissions.Besides,the multi-form energy conversion of multi-stage regenerative CAES and storage efficiency is verified,especially its incomparable superiority in solving the uncertainty problem in wind and solar power generation.Finally,the propaganda and application scenario of the CAES system in China is introduced.
MEI Sheng WeiWANG Jun JieTIAN FangCHEN Lai JunXUE Xiao DaiLU QiangZHOU YuanZHOU Xiao Xin
Increased penetration of large-scale renewable sources such as wind and solar power creates additional constraints for power system maintenance,reliability and security.The intermittent and fluctuation characteristics of renewable energy require robust operation methodologies.Co-optimized scheduling of multiple energy resources is regarded as an efficient way to accommodate renewable energy.As the second largest source of electricity in the world,hydro power is clean and has the merits of ease of regulation,low cost and high flexibility.In this regard,it can play an important role in mitigating the uncertainty of wind power.This paper proposes a robust wind-hydro-thermal unit commitment(UC)model that provides reliable day-ahead unit commitment decisions.The hydro units are operated in longer time scales than the thermal units,so as to capture reservoir operations.The hydro production capability curve is linearized by using variable separation and the piecewise linear(PWL)function,leading to a mixed integer linear programming(MILP)problem that can be solved using mature software such as CPLEX.Numerical tests on an IEEE 39-bus system demonstrate the effectiveness of the proposed model to increase system flexibility in accommodation of uncertain wind power.
具有出力不确定性和反调峰特性的可再生能源大规模并网给电力系统调度运行带来了新的挑战。压缩空气储能(Compressed Air Energy Storage,CAES)系统以其调节速率快、选址灵活、使用寿命长等特点为解决可再生能源利用率低这一难题提供了新的解决思路。特别地,回热式压缩空气储能(Regenerative CAES,RCAES)系统因可以有效利用压缩过程释放的热量而备受关注。能量转换效率是RCAES系统的重要性能指标,但当前研究集中在系统热力学过程分析上,对其效率评估研究有限。本文从RCAES系统的电能-机械能-热能转换过程及基准参数出发,提出了一种RCAES系统效率评估方法。通过某典型RCAES系统设计方案,本文对所提方法进行了详细计算说明,验证了其合理性。
