With deepening reform in retail side market of electric power, it is of great significance to explore transaction and bidding mechanism of electricity distribution market with multiple microgrids. In this paper, the bidding process is solved as a bi-level optimization problem. The lower level minimizes cost of electricity purchasing for distribution system operator, where both node voltage constraints and branch power flow constraints are considered to ensure safe operation of the system. Path-following interior point algorithm is employed to clear the market and obtain an economic dispatch scheme. In the upper level, the profit of each microgrid operator is maximized. Optimal bidding strategies of microgrid operators are determined with genetic algorithm under coalitional and independent conditions. Nash equilibrium of the electricity distribution market is achieved based on dynamic game under complete information. Testing results on IEEE 33-bus system demonstrate validity of the proposed method. In addition, economic performance of each market subject is further analyzed concerning reactive power auxiliary service from microgrid operators.
KEY WORDS :microgrid;distribution electricity market;bi-level optimization;dynamic game;
在竞争性电力市场中,发电商向市场运营商提交竞标时段的报价和相应的可用容量,市场运营商根据报价信息和负荷需求确定各个发电商的中标电量和市场的清算电价。其中,发电商的目标是通过报价竞争,最大化自身的收益;市场运营商的目标则是在确保系统负荷需求得到满足的前提下,最小化购电成本,实现社会效益最大化。在市场竞价和清算过程中,一方面发电商和市场运营商独立地优化各自的目标,另一方面两者之间又同时受到彼此行为的影响。因此,该模型可以描述为一个双层规划问题[9-16]。对于此类问题,常用的求解方法是将双层问题转化为单层问题,例如文献[9-11]将发电商在日前电力市场的最优竞价策略问题转化为带平衡约束的数学规划问题(mathematical program with equilibrium constraints,MPEC),随后利用二进制扩充法[9-10]或者库恩-塔克(Karush-Kuhn-Tucker,KKT)条件[11]将MPEC转化为混合整数线性规划(mixed integer linear program,MILP)问题进行求解;另一种方法采用供应函数均衡模型确定发电商的最优竞价策略[12-14]。该方法认为发电商的报价一般会高于其边际发电成本,通过改变供应函数的截距或斜率可优化自身的收益。其中,文献[14]在批发市场和配电市场中引入了负荷聚合商,分析了微电网、发电公司和负荷聚合商3者之间基于完全信息下的动态博弈行为,通过收益函数对报价策略的灵敏度矩阵更新自身的报价策略,直至市场达到均衡。除此之外,文献[15]提出了一种多领导者单追随者的非线性双层规划模型,并采用粒子群算法求解系统的广义纳什均衡点。文献[16]提出了一种非线性互补算法对此类双层规划问题进行求解。
本文所研究的配电侧日前电力市场结构如图1所示。配电系统运营商(distribution system operator,DSO)负责市场的运行和清算,各市场主体需要将竞价信息上报DSO。其中,电力零售商拥有该区域内的负荷资源,需要在配电市场中购买电能以满足第2日的负荷需求,其提交至DSO的信息为预测的第
[1]
王成山,武震,李鹏.微电网关键技术研究[J].,2014,29(2):1-12.WangChengshan,WuZhen,LiPeng.Research on key technologies of microgrid[J].,2014,29(2):1-12(in Chinese).
[2]
王蓓蓓,赵盛楠,刘小聪,等.面向可再生能源消纳的智能用电关键技术分析与思考[J].,2016,40(12):3894-3903.WangBeibei,ZhaoShengnan,LiuXiaocong,et al.Review on key technologies of smart power utilization for renewable energy integration[J].,2016,40(12):3894-3903(in Chinese).
[3]
张丹,王杰.国内微电网项目建设及发展趋势研究[J].,2016,40(2):451-458.ZhangDan,WangJie.Research on construction and development trend of micro-grid in China[J].,2016,40(2):451-458(in Chinese).
[4]
程林,刘琛,朱守真,等.基于多能协同策略的能源互联微网研究[J].,2016,40(1):132-138.ChengLin,LiuChen,ZhuShouzhen,et al.Study of micro energy internet based on multi-energy interconnected strategy[J].,2016,40(1):132-138(in Chinese).
[5]
BieZ,ZhangP,LiG,et al.Reliability evaluation of active distribution systems including microgrids[J].,2012,27(4):2342-2350.
[6]
邢海军,程浩忠,张沈习,等.主动配电网规划研究综述[J].,2015,39(10):2705-2711.XingHaijun,ChengHaozhong,ZhangShenxi,et al.Review of active distribution network planning[J].,2015,39(10):2705-2711(in Chinese).
[7]
乐健,柳永妍,叶曦,等.含高渗透率分布式电能资源的区域电网市场化运营模式[J].,2016,36(12):3343-3353.LeJian,LiuYongyan,YeXi,et al.Market-oriented operation pattern of regional power network integration with high penetration level of distributed energy resources[J].,2016,36(12):3343-3353(in Chinese).
[8]
Bakirtzis AG,Ziogos NP,Tellidou AC,et al.Electricity producer offering strategies in day-ahead energy market with step-wise offers [C]//Bulk Power System Dynamics and Control VII.Revitalizing Operational Reliability.Charleston,SC,,2007:1-18.
[9]
窦春霞,贾星蓓,李恒.基于多智能体的微电网中分布式发电的市场博弈竞标发电[J].,2016,40(2):579-586.DouChunxia,JiaXingbei,LiHeng.Multi-agent-system-based market bidding strategy for distributed generation in microgrid[J].,2016,40(2):579-586(in Chinese).
[10]
Bakirtzis AG,Ziogos NP,Tellidou AC,et al.Electricity producer offering strategies in day-ahead energy market with step-wise offers[J].,2007,22(4):1-18.
[12]
LiJ,LiZ,WangY.Optimal bidding strategy for day-ahead power market[C]//North American Power Symposium.Charlotte,NC,,2015:1-6.
[13]
TaheriI,RashidinejadM,BadriA,et al.Analytical approach in computing nash equilibrium for oligopolistic competition of transmission-constrained GENCOs[J].,2014,16(6):1-11.
[14]
Manshadi SD,Khodayar ME.A hierarchical electricity market structure for the smart grid paradigm[J].,2016,7(4):1866-1875.
[15]
ZhangG,ZhangG,GaoY,et al.Competitive strategic bidding optimization in electricity markets using bilevel programming and swarm technique[J].,2011,58(6):2138-2146.
[16]
LiH,LiY,LiZ.A multiperiod energy acquisition model for a distribution company with distributed generation and interruptible load[J].,2007,22(2):588-596.
[17]
赵敏,沈沉,刘锋,等.基于博弈论的多微电网系统交易模式研究[J].,2015,35(4):848-857.ZhaoMin,ShenChen,LiuFeng,et al.A game-theoretic approach to analyzing power trading possibilities in multi-microgrids[J].,2015,35(4):848-857(in Chinese).
[18]
史开拓,刘念,张建华,等.多运营主体的微电网随机匹配交易机制[J].,2016,40(2):587-594.ShiKaituo,LiuNian,ZhangJianhua,et al.Random matching trading mechanism in microgrid of multi-operators[J].,2016,40(2):587-594(in Chinese).
[19]
江润洲,邱晓燕,李丹.基于多代理的多微网智能配电网动态博弈模型[J].,2014,38(12):3321-3327.JiangRunzhou,QiuXiaoyan,LiDan.Multi-agent system based dynamic game model of smart distribution network containing multi-microgrid[J].,2014,38(12):3321-3327(in Chinese).
[20]
郭红霞,白浩,刘磊,等.统一电能交易市场下的虚拟电厂优化调度模型[J].,2015,30(23):136-145.GuoHongxia,BaiHao,LiuLei,et al.Optimal scheduling model of virtual power plant in a unified electricity trading market[J].,2015,30(23):136-145(in Chinese).
[23]
Moradi MH,AbediniM,Hosseinian SM.A combination of evolutionary algorithm and game theory for optimal location and operation of DG from DG owner standpoints[J].,2015,7(2):1-1.