基金项目:
国家电网公司科技项目“提高光伏扶贫地区电网消纳能力与保障技术的研究与应用”;
Project Supported by Technology Project of State Grid Corporation of China (Research and Application of Improving Accommodation Capacity and Support Technology for PVs in Poverty Area);
It is critical that accommodation and application of residential photovoltaics (PVs) help to mitigate environment and energy crisis. Voltage problems caused by high proportion of residential PVs have become one of key factors restricting hosting capacity of low voltage distribution network (LVDN) for PVs. Voltage problems in LVDN with high proportion of residential PVs are described and voltage control principle based on voltage sensitivity is presented in this paper. Based on this, overview about voltage control strategies of LVDN depending on active and reactive power control, tap changer control and coordination control with multiple devices are presented. Application scenarios, advantages and shortcomings of these researches are summarized and future development trend about voltage control in LVDN with high proportion of residential PVs are prospected.
KEY WORDS :residential PV;LV distribution network;voltage control;voltage violation;voltage variation;
图1
常见的低压配电网通信配置图
Fig. 1
Communication configuration figure of common low voltage distribution network
3.2 基于有功的电压控制方法
3.2.1 光伏并网有功削减
在r显著大于x的低压配网中,削减户用光伏并网功率是一种非常简单有效的抑制网络过电压的方法,并且可以有助于降低过电压情形下线路中的有功流动,从而降低网络损耗。图2为一种常用的光伏有功削减曲线,其中,PPV为光伏并网有功,若并网节点的电压低于允许电压上限Vth-OV时,光伏发电按照最大功率点跟踪(maximum power point tracking,MPPT)功率并网;若并网节点的电压超过允许电压上限时,光伏发电不再按照MPPT功率并网,而按照预定的电压-有功曲线切除光伏并网有功。多数研究均以此为基础提出控制策略[37-39],但是仅仅以防止各节点电压不越限为目标,不考虑各
图2
电压-有功控制曲线
Fig. 2
Control curve under voltage-activepower strategy
[1]
刘健,黄炜.分布式光伏电源与负荷分布接近条件下的可接入容量分析[J].,2015,39(2):299-306.LiuJian,HuangWei.Analysis on grid-connectible capacity of distributed PV generation in case of PV generation distribution close to load distribution[J].,2015,39(2):299-306(in Chinese).
[2]
郑超,林俊杰,赵健,等.规模化光伏并网系统暂态功率特性及电压控制[J].,2015,35(5):1059-1071.ZhengChao,LinJunjie,ZhaoJian,et al.Transient power characteristic of scaled photovoltaic grid-connected system and its voltage control[J].,2015,35(5):1059-1071(in Chinese).
[3]
左伟杰,马钊,周莉梅,等.基于配电网电能质量健康评估策略的分布式光伏接入方法[J].,2015,39(12):3442-3448.ZuoWeijie,MaZhao,ZhouLimei,et al.Grid-connection of distributed photovoltaic generation method based on the power quality health status of distribution system[J].,2015,39(12):3442-3448(in Chinese).
[4]
马丽,刘念,张建华,等.自动需求响应模式下光伏用户群的优化运行模型[J].,2016,36(13):3422-3432.MaLi,LiuNian,ZhangJianhua,et al.Optimal operation model of user group with photovoltaic in the mode of automatic demand response[J].,2016,36(13):3422-3432(in Chinese).
[5]
赵晋泉,刘绪,林昌年,等.单相光伏大量接入的三相不平衡配电网无功优化[J].,2016,40(13):13-18.ZhaoJinquan,LiuXu,LinChangnian,et al.Three-phase unbalanced reactive power optimization for distribution systems with a large numberof single phase solar generators[J].,2016,40(13):13-18(in Chinese).
[6]
Mejbaul HM,PeterW.,2016(62):1195-1208.
[7]
LiQ,WolfsP.A review of the single phase photovoltaic module integrated converter topologies with three different DC link configurations[J].,2008,23(3):1320-1333.
[8]
NasifM,ZahediA.,2016(64):582-595.
[9]
BenoitB,SerdarK,RomanB,et al.Voltage control with PV inverters in low voltage networks-in depth analysis of different concepts and parameterization criteria[J].,2017,32(1):177-185.
[10]
AfshinS,RobertE,LennartS,et al.Coordinated active power-dependent voltage regulation in distribution grids with PV systems[J].,2014,29(3):1454-1464.
[11]
KarlW,Kellett CM,PhilippB,et al.Distributed and decentralized control of residential energy systems incorporating battery storage[J].,2015,6(4):1914-1923.
[12]
Alam M JE,Muttaqi KM, SutantoD.A multi-mode control strategy for var support by solar PV inverters in distribution networks[J].,2015,30(3):1316-1326.
[13]
SamW,JohanD.Optimal local reactive power control by PV inverters[J].,2016,7(4):1624-1633.
[14]
许晓艳,黄越辉,刘纯,等.分布式光伏发电对配电网电压的影响及电压越限的解决方案[J].,2010,34(10):140-146.XuXiaoyan,HuangYuehui,LiuChun,et al.The solution of distributed PV generation on distribution network voltage and voltage limit[J].,2010,34(10):140-146(in Chinese).
[15]
王颖,文福拴,赵波,等.高密度分布式光伏接入下电压越限问题的分析与对策[J].,2016,36(5):1200-1206.WangYing,WenFushuan,ZhaoBo,et al.Analysis and countermeasures of voltage violation problems caused by high-density distributed photovoltaics[J].,2016,36(5):1200-1206(in Chinese).
[16]
AhmedE-N,IstvànE.Control approach of three-phase grid connected PV inverters for voltage unbalance mitigation in low-voltage distribution grids[J].,2016,10(10):1577-1586.
[17]
刘科研,何开元,盛万兴.基于协同粒子群优化算法的配电网三相不平衡状态估计[J].,2014,38(4):1026-1031.LiuKeyan,HeKaiyuan,ShengWanxing.A cooperative particle swarm optimization based state estimation of unbalanced three-phase distribution network[J].,2014,38(4):1026-1031(in Chinese).
[19]
温阳东,王欣.分布式发电对配电网继电保护的影响[J].,2008,36(1):12-14.WenYangdong,WangXin.Effect of distributed generation on protection in distribution system[J].,2008,36(1):12-14(in Chinese).
[20]
Procopiou AT,Ochoa LF.Voltage control in PV-rich LV networks without remote monitoring[J].,2017,32(2):1224-1236.
[21]
LongC,O L F.Voltage control of PV-rich LV networks: OLTC-fitted transformer and capacitor banks[J].,2016,31(5):4016-4025.
[22]
ReinaldoT,Lopes L A C,El-Fouly T H M.Coordinated active power curtailment of grid connected PV inverters for overvoltage prevention[J].,2011,2(2):139-147.
[23]
张璐,唐巍,丛鹏伟,等.含光伏发电的配电网有功无功资源综合优化配置[J].,2014,34(31):5525-5533.ZhangLu,TangWei,CongPengwei,et al.Optimal configuration of active-reactive power sources in distribution network with photovoltaic generation[J].,2014,34(31):5525-5533(in Chinese).
[24]
MorrisB,Ettore DB,Luca DC,et al.Automatic distributed voltage control algorithm in smart grids applications[J].,2013,4(2):877-885.
[25]
Alam M JE,Muttaqi KM,SutantoD.A SAX-based advanced computational tool for assessment of clustered rooftop solar PV impacts on LV and MV networks in smart grid[J].,2013,4(1):577-585.
[26]
李清然,张建成.含分布式光伏电源的配电网电压越限解决方案[J].,2015,39(22):117-123.LiQingran,ZhangJiancheng.Solutions of voltage beyond limits in distribution network with distributed photovoltaic generators[J].,2015,39(22):117-123(in Chinese).
[27]
AbdullahB,AshharR,MarcD-A,et al.Combined effect of CVR and DG penetration in the voltage profile of low-voltage secondary distribution networks[J].,2016,31(1):286-293.
[28]
IzudinD,Jabr RA,EmaH,et al.A sensitivity approach to model local voltage controllers in distribution networks[J].,2014,29(3):1419-1428.
[29]
AlbertoB,MauroB,SamueleG,et al.Short-term scheduling and control of active distribution systems with high penetration of renewable resources[J].,2010,4(3):313-322.
[31]
MorrisB,Ettore DB,Luca DC,et al.Automatic distributed voltage control algorithm in smart grids applications[J].,2013,4(2):877-885.
[32]
蔡永翔,张璐,唐巍,等.考虑逆变器无功充裕性的含高比例户用光伏低压配电网电压控制策略[J].,2017,41(9):2799-2807.CaiYongxiang,ZhangLu,TangWei,et al.A voltage control strategy for LV distribution network with high proportion residential PVs considering reactive power adequacy of PV inverters[J].,2017,41(9):2799-2807(in Chinese).
[33]
ThomasS,FrankM,MartinB.Improved low voltage grid-integration of photovoltaic systems in Germany[J].,2013,4(2):534-542.
[34]
TonkoskiR,Lopes L A C.Impact of active power curtailment on overvoltage prevention and energy production of PV inverters connected to low voltage residential feeders[J].,2011,36(12):3566-3574.
[35]
Farag H EZ,El-Saadany EF.A novel cooperative protocol for distributed voltage control in active distribution systems[J].,2013:1645-1656.
[36]
WangY,Tan KT,Peng XY,et al.Coordinated control of distributed energy-storage systems for voltage regulation in distribution networks[J].,2016,31(3):1132-1141.
[37]
KeigoS,AkikoT,ImaiJun,et al.A novel voltage control method in low-voltage distribution systems:cooperative autonomous switching control[C]//Industrial Electronics Society,IECON 2015- Conference of the IEEE.Yokohama,,2015:583-588.
[38]
Wai KY,HavasL,OverendE,et al.Neural network-based active power curtailment for overvoltage prevention in low voltage feeders[J].,2014,41(4):1063-1070.
[39]
TonkoskiR,LopesL.Voltage regulation in radial distribution feeders with high penetration of photovoltaic[C]//Energy 2030 Conference,2008.Atlanta,,2008:1-7.
[40]
WangP,Liang DH,YiJ,et al.Integrating electrical energy storage into coordinated voltage control schemes for distribution networks[J].,2014,5(2):1018-1032.
[41]
GillS,KockarI,Ault GW.Dynamic optimal power flow for active distribution networks[J].,2014,29(1):121-131.
[42]
WongJ,Lim YS,MorrisE.Novel fuzzy controlled energy storage for low-voltage distribution networks with photovoltaic systems under highly cloudy conditions[J].,2015,141(1):B4014001.
[43]
AlamM,MuttaqiK,SutantoD.A novel approach for ramp-rate control of solar PV using energy storage to mitigate output fluctuations caused by cloud passing[J].,2014,29(2):507-518.
[44]
Chua KH,Yun SL,TaylorP,et al.Energy storage system for mitigating voltage unbalance on low-voltage networks with photovoltaic systems[J].,2012,27(4):1783-1790.
[45]
Kein HC,Yun SL,JianhuiW,et al.Voltage unbalance mitigation in low voltage distribution networks with photovoltaic systems[J].,2012,10(1):1-6.
[46]
WangY,Wang BF,Ping LS.A voltage regulation method using distributed energy storage systems in LV distribution networks [C]//IEEE International Energy Conference.Leuven,, 2016:1-6.
[47]
WorthmannK,Kellett CM,BraunP,et al.Distributed and decentralized control of residential energy systems incorporating battery storage[J].,2015,6(4):1914-1923.
[48]
WangL,Liang DH,Crossland AF,et al.Coordination of multiple energy storage units in a low-voltage distribution network[J].,2015,6(6):2906-2918.
[49]
OlekB,WierzbowskiM.Local energy balancing and ancillary services in low-voltage networks with distributed generation, energy storage, and active loads[J].,2015,62(4):2499-2508.
[50]
SugiharaH,YokoyamaK,SaekiO,et al.Economic and efficient voltage management using customer-owned energy storage systems in a distribution network with high penetration of photovoltaic systems[J].,2013,28(1):102-111.
[51]
KabiriR,Holmes DG,McGrath B P,et al.LV grid voltage regulation using transformer electronic tap changing,with PV inverter reactive power injection[J].,2015,3(4):1182-1192.
[52]
CENELEC.EN 50160 Voltage characteristics of electricity supplied by public distribution networks[S].,2010.
[54]
DemirokE,González PC,Frederiksen K H B,et al.Local reactive power control methods for overvoltage prevention of distributed solar inverters in low-voltage grids[J].,2011,1(2):174-182.
[55]
Pham HV,Rueda JL,ErlichI.Probabilistic evaluation of voltage and reactive power control methods of wind generators in distribution networks[J].,2014,9(3):195-206.
[56]
MokhtariG,GhoshA,NourbakhshG,et al.Smart robust resources control in LV network to deal with voltage rise issue[J].,2013,4(4):1043-1050.
[57]
Vasquez JC,Mastromauro RA,Guerrero JM,et al.Voltage support provided by a droop-controlled multifunctional inverter[J].,2009,56(11):4510-4519.
[58]
JahangiriP,Aliprantis DC.Distributed volt/var control by PV inverters[J].,2013,28(3):3429-3439.
[60]
BletterieB.Local voltage control by PV inverters:first operating experience from simulation,laboratory tests and field tests[C]// European Photovoltaic Solar Energy Conference and Exhibition.Paris,,2013:4210-4216.
[61]
WangH,StetzT,KraiczyM,et al.Parallel operation of photovoltaic inverters with autonomous voltage control strategies comparison of Q(V)/P(V) and automatic voltage limitation[C]//European Photovoltaic Solar Energy Conference EUPVSEC.Amsterdam,,2014:2921-2926.
[62]
LongC,Procopiou AT,Ochoa LF,et al.Performance of OLTC-based control strategies for LV networks with photovoltaics [C]//2015 IEEE Power & Energy Society General Meeting.Denver,,2015:1-5.
[63]
LongC,Ochoa LF.Voltage Control of PV-Rich LV Networks:OLTC-Fitted Transformer and Capacitor Banks[J].,2016,31(5):4016-4025.
[64]
Muttaqi KM,Le A D T,Negnevitsky M,et al.A coordinated voltage control approach for coordination of OLTC, voltage regulator, and DG to regulate voltage in a distribution feeder[J].,2015,51(2):1239-1248.
[65]
LiuX,AichhornA,LiuL,et al.Coordinated control of distributed energy storage system with tap changer transformers for voltage rise mitigation under high photovoltaic penetration[J].,2012,3(2):897-906.
[66]
Kabir MN,MishraY,LedwichG,et al.Coordinated control of grid-connected photovoltaic reactive power and battery energy storage systems to improve the voltage profile of a residential distribution feeder[J].,2014,10(2):967-977.
[67]
吴聪,唐巍,白牧可,等.基于能源路由器的用户侧能源互联网规划[J].,2017,41(4):20-28.WuCong,TangWei,BaiMuke,et al.Energy router based planning of energy internet at user side[J].,2017,41(4):20-28(in Chinese).
[68]
宋强,赵彪,刘文华,等.智能直流配电网研究综述[J].,2013,33(25):9-19.SongQiang,ZhaoBiao,LiuWenhua,et al.An overview of research on smart DC distribution power network[J].,2013,33(25):9-19(in Chinese).
[69]
BokyungK,Utomo NP,JangG,et al.Optimal scheduling for the complementary energy storage system operation based on smart metering data in the DC distribution system[J].,2013,6(12):6569-6585.
[70]
HakalaT,LahdeahoT,JarventaustaP.Low-voltage DC distribution- utilization potential in a large distribution network company[J].,2015,30(4):1694-1701.
[71]
Hamad AA,Farag HE,El-Saadany E F.A novel multiagent control scheme for voltage regulation in DC distribution systems[J].,2015,6(2):534-545.
[72]
PeiW,DengW,ZhangX,et al.Potential of using multiterminal LVDC to improve plug-in electric vehicle integration in an existing distribution network[J].,2015,62(5):3101-3111.
[73]
ElNozahy MS,Salama M MA.uncertainty-based design of a bilayer distribution system for improved integration of PHEVs and PV arrays[J].,2015,6(3):659-674.
[74]
AlatrashH,MensahA,MarkE,et al.Generator emulation controls for photovoltaic inverters[J].,2012,3(2):996-1011.
[76]
郑天文,陈来军,刘炜,等.考虑源端动态特性的光伏虚拟同步机多模式运行控制[J].,2017,37(2):454-464.ZhengTianwen,ChenLaijun,LiuWei,et al.Multi-mode operation control for photovoltaic virtual synchronous generator considering the dynamic characteristics of primary source[J].,2017,37(2):454-464(in Chinese).