RESEARCH ARTICLE Smart grid adds to renewable resources hosting capacity: Collaboration of plug‐in hybrid electric vehicles in Volt/VAr control process Amir Hamidi | Daryoush Nazarpour | Sajjad Golshannavaz Electrical Engineering Department, Urmia University, Urmia, Iran Correspondence Sajjad Golshannavaz, Electrical Engineering Department, Urmia University, Urmia, Iran. Email: s.golshannavaz@urmia.ac.ir Summary This paper develops an efficient energy management approach to increase the renewables share in energy provision of smart distribution grids (SDGs). Volt- age violation ends in curtailment of renewables generations and, hence, decreases the economic success of distribution companies. To avert such defi- cits, this study fosters the collaboration of SDG components in an intelligent Volt/VAr control process. The investigated SDG is characterized with high pen- etration of photovoltaics (PVs), dispatchable distributed generations (DDGs), plug‐in hybrid electric vehicles (PHEVs), and infield control devices say as under‐load tap‐changing transformers (ULTCs). In charge stations, PHEVs are coupled to the SDG through bidirectional inverters which are offering simultaneous exchanges of active and reactive powers. Thus, regarding the PHEV aggregators, optimal schedules of active power charge/discharge signals with their inductive/capacitive reactive power provisions are determined. This notion effectively increases PV power injections and, consequently, provides significant monetary savings. Besides, this mechanism reduces ULTC tap oper- ations in Volt/VAr control process maintaining its nominal lifetime. The Nomenclature Indices, Sets, and Symbols: i , j , B, Indices and set of busses; br, Index of feeders; a , A, Index and set of PHEV aggregators; e , E, Index and set of PHEVs at each aggregator; t , T, Index and set of time intervals; k , K, Index and set of different components in SDG; p , q, Indices of active and reactive powers, respectively; ; ¯ , Symbols for maximum and minimum values, respectively; ∣∣, Symbol for representing the magnitude of variables Parameters: A PV , PV panel surface area (m 2 ); I PV , Solar irradiance (kW/m 2 ); Z A , Binary parameter denoting the availability of PHEVs in aggregators; t d , Departure time of PHEVs; SOC ar , PHEV initial SOC; SOC f , PHEV desired SOC; P d , Q d , Active and reactive power demands (MW, MVAr); a DDG , b DDG , c DDG , Cost function coefficients of DDGs ($, $/MW, $/MW 2 ); U DDG , D DDG , Startup and shutdown costs of DDGs; c tap , Cost of each tap changing action ($/tap); r p , r q , Wholesale electricity prices for active and reactive powers, respectively ($/MW, $/MVAr); G , B, Conductance and susceptance of each branch (Ω -1 ); S ULTC , Apparent power through the substation transformer (MVA); S CS , Apparent power of PHEVs charge station inverter (MVA); S DDG , DDG apparent power (MVA); S PV , Apparent power of PV inverter (MVA); η ch , η dch , Charging and discharging efficiencies; η PV , Efficiency of PV inverter Variables and Functions: P DDG , DDG active power (MW); Q DDG , DDG reactive power (MVAr); PF DDG , DDG power factor; P PV , PV active power (MW); P ch , P dch , Charging and discharging power of PHEV (MW); P PHEV , PHEV net active power transfer (MW); P A , Active power exchange of PHEV aggregator (MW); Q A , Reactive power exchange of PHEV aggregator (MVAr); SOC, PHEV SOC; A DDG , Binary variable representing the status of DDG; h up , Binary variable denoting the startup decision of DDD; h do , Binary variable denoting the shutdown decision of DDG; Tap, Tap position of ULTC; N tap , Daily tap operations of ULTC; C ULTC , Daily costs of ULTC tap operations ($); P in , Q in , Imported active and reactive power from substation (MW, MVAr); V, Voltage magnitude (p.u.); S br , Power flow through each feeder (MVA); θ, Voltage phase angle difference (rad) Acronyms: SDG, Smart distribution grid; DSO, Distribution system operator; PV, Photovoltaics; DDG, Dispatchable distributed generator; PHEV, Plug‐in hybrid electric vehicle; DMS, Distribution management system; ULTC, Under‐load tap changer (ULTC); PF, Power factor; SOC, State of charge Received: 8 June 2017 Revised: 17 July 2017 Accepted: 17 July 2017 DOI: 10.1002/er.3843 Int J Energy Res. 2017;1–15. Copyright © 2017 John Wiley & Sons, Ltd. wileyonlinelibrary.com/journal/er 1