Residential energy optimization control method based on V2B, V2G and electric energy sharing

Abstract

The invention relates to the technical field of power utilization management of a power system, in particular to a residence energy optimization control method based on V2B, V2G and electric energy sharing, and the method comprises the steps: obtaining an electric vehicle cluster participating in ordered discharge in each building in each time period; according to the electric vehicle discharge time model, the discharge sequence of electric vehicle clusters participating in ordered discharge in each building in each time period is determined; according to the load capacity of each building in each time period, determining an ordered discharge mode in which the electric vehicle cluster participating in ordered discharge participates in each building in each time period; and obtaining the minimum value of the energy consumption cost of each building based on the electric energy cost of the power grid purchased by each building in each time period within the preset time and the electric vehicle discharging electric energy cost, and combining the battery loss cost generated by charging and discharging of the electric vehicle of each building to obtain the minimum value of the energy consumption cost of each building. According to the invention, charging and discharging of the electric vehicle are guided orderly, the load peak-valley difference is reduced, the operation efficiency and reliability of the power grid are improved, and the investment of the power grid on distribution network construction is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of power system electricity management, and in particular to a residential energy optimization control method based on V2B, V2G and power sharing. Background Art

[0002] With the development of new energy, actively exploring the bidirectional charging and discharging application mode of efficient integration of new energy vehicles with buildings, homes and other scenarios is a new research direction in the field of power system power management technology. In order to meet the requirements of the future energy revolution on the consumer side, there will be three development directions: 1) electric vehicles plus smart charging piles. Electric vehicles are flexible power loads, and their renewable electricity can replace fossil fuel; 2) distributed batteries in buildings; 3) demand-side response to flexible power terminal loads.

[0003] The research on the application mode of bidirectional charging and discharging in the prior art includes: the document "Smart Home Energy Optimization Control Strategy of Hybrid Energy Collaborative Control" proposes a smart home energy optimization control model of hybrid energy collaborative control with electricity cost and user comfort as optimization targets; the document "Real-time Energy Scheduling Strategy of Home Microgrid Considering Uncertainty of Electric Vehicles" proposes a Markov chain Monte Carlo (MCMC)-based method to model the randomness of electric vehicles, but does not consider the responsiveness of electric vehicles in practice; the document "Orderly Charging and Discharging Strategy of Electric Vehicles Considering User Responsiveness" establishes an electric vehicle responsiveness model based on consumer psychology, but the model cannot meet the time when all electric vehicles return home and leave home, and the model needs to be further improved; the document "Day-ahead Collaborative Optimization Scheduling of Integrated Energy Building Group Considering Electricity Sharing" considers electric vehicle-grid (V2G) in the day-ahead collaborative optimization scheduling of integrated energy building groups, and does not consider the application of electric vehicle-building (V2G). Building, V2B) can improve the local consumption rate of clean energy and further reduce the electricity costs of residents; the smart building group power optimization model established in the document "Day-ahead optimization and sharing of power in smart building groups" only considers the battery loss cost of electric vehicles, but does not consider the battery loss of storage batteries; the application document with application number "2018107339594" studies the charging and discharging behavior characteristics of electric vehicles, and constructs a model for the coexistence of V2B and V2G application scenarios for electric vehicles, which can provide technical support for the charging and discharging management of electric vehicles parked in building parking lots in the future; the device for the coexistence of V2B and V2G application scenarios can be used to calculate and optimize the electricity costs of buildings.

[0004] In summary, the interaction mode between electric vehicles and buildings in the prior art is mostly a single V2B or V2G mode. The few interaction modes consider both V2B and V2G modes, but the interaction is only between electric vehicles and single buildings or between electric vehicles and power grids. It does not consider linking electric vehicles with all buildings and power grids in the community to exchange electricity, resulting in failure to meet users' charging needs, thereby increasing car owners' electricity purchase expenses, and causing low grid operation efficiency and reliability, increasing the grid's investment in distribution network construction, and increasing electricity costs between buildings. Summary of the invention

[0005] To this end, the technical problem to be solved by the present invention is to overcome the problem that the prior art does not consider linking electric vehicles with all buildings and power grids in the entire community to exchange electric energy, resulting in the inability to meet the charging needs of users, thereby increasing the owner's electricity purchase expenses, and causing low grid operation efficiency and reliability, increasing the grid's investment in distribution network construction, and increasing the electricity costs between buildings.

[0006] In order to solve the above technical problems, the present invention provides a residential energy optimization control method based on V2B, V2G and power sharing, comprising:

[0007] Obtain the electric vehicle clusters in each building in each time period whose arrival time is during the peak electricity price period and whose charge state value when arriving home is greater than the minimum charge state threshold, and obtain the electric vehicle clusters participating in orderly discharge in each building in each time period;

[0008] According to the electric vehicle discharge time model, the discharge order of the electric vehicle cluster participating in orderly discharge in each building in each period is determined;

[0009] If the current building load in the t-th period is greater than zero, the electric vehicle cluster participating in the orderly discharge in the current building in the t-th period enters the V2B orderly discharge mode; based on the constructed electric vehicle V2B discharge model, the actual discharge amount of the electric vehicle cluster participating in the V2B orderly discharge mode in the current building in the t-th period is obtained;

[0010] If the load of the current building in the tth period is equal to zero, and the load of other buildings in the residential area is greater than zero, then the electric vehicle cluster participating in the orderly discharge of the current building in the tth period enters the electric energy sharing orderly discharge mode, and the current building is regarded as the surplus power building; all buildings in the residential area with a load equal to zero in the tth period are regarded as the surplus power building cluster, and all buildings with a load greater than zero are regarded as the power-deficient building cluster; based on the constructed electric vehicle-building power sharing model, the actual discharge of all electric vehicle clusters participating in the electric energy sharing orderly discharge mode in the surplus power building cluster in the tth period is obtained; the dispatching control center obtains the actual discharge of each surplus power building in the tth period through the load and available discharge of each surplus power building in the tth period;

[0011] If the load of all buildings in the residential area is zero in the tth period, the electric vehicle cluster participating in the orderly discharge of the current building in the tth period enters the V2G orderly discharge mode; based on the constructed electric vehicle V2G discharge model, the actual discharge amount of the electric vehicle cluster participating in the V2G orderly discharge mode in the current building in the tth period is obtained;

[0012] Based on the electric vehicle battery loss model, the battery loss cost caused by charging and discharging electric vehicles in each building is obtained;

[0013] According to the actual discharge amount of the electric vehicle cluster participating in each discharge mode in each building in each period within the preset time, the load of each building in each period, and the electricity sales price and electricity purchase price based on the time-of-use electricity price, the minimum value of the grid electricity purchase cost and electric vehicle discharge electricity cost of each building in each period within the preset time is obtained, and then combined with the battery loss cost generated by the charging and discharging of electric vehicles in each building, the minimum energy consumption cost of each building is obtained.

[0014] Preferably, the expression for the minimum value of the energy consumption cost of each building is:

[0015]

[0016] Among them, f i represents the energy consumption cost of the i-th building; T D represents the preset time; t represents the tth period; Δt represents the time interval; λ sell , buy The electricity price of electric vehicle discharge adopts the electricity price of time-of-use electricity price λ sell ;p g，i (t) indicates the purchase of grid electricity by the i-th building in the t-th period; p evd，i (t) represents the electric energy discharged by the electric vehicle purchased by the i-th building in the t-th period; C ev，i represents the battery loss cost caused by charging and discharging of electric vehicles in the i-th building;

[0017] The dispatching and control center obtains the electric energy discharged by electric vehicles purchased by each building in each period through the actual discharge amount of the electric vehicle cluster participating in each discharge mode in each building in each period within the preset time and the load amount of each building in each period.

[0018] Preferably, the constructed electric vehicle V2B discharge model is:

[0019] P V2B (t) = min{P evd，V2B (t)η evd η AC-DC , P L (t)}

[0020] Among them, P V2B (t) represents the actual discharge amount of the electric vehicle cluster participating in the V2B orderly discharge mode in the current building in the tth period; P L (t) represents the current building load in the tth period; P evd，V2B (t) represents the available discharge capacity of the electric vehicle cluster participating in the V2B orderly discharge mode in the current building in the tth period; η evd Represents the discharge efficiency of electric vehicles; η AC-DC Indicates the AC-DC converter conversion efficiency.

[0021] Preferably, the constructed electric vehicle-building power sharing model is:

[0022] P ev，TSP (t) = min{P TBP (t), P evd，TSP (t)η DC-AC}

[0023] Among them, P ev，TSP (t) represents the actual discharge capacity of all electric vehicle clusters participating in the orderly discharge mode of power sharing in the surplus power building cluster in the tth period; P TBP (t) represents the load of the power-deficient building cluster in the tth period; P evd，TSP (t) represents the available discharge capacity of all electric vehicle clusters participating in the orderly discharge mode of power sharing in the surplus power building cluster in the tth period; η DC-AC Indicates the DC-AC converter conversion efficiency.

[0024] Preferably, the constructed electric vehicle V2G discharge model is:

[0025] P V2G (t) = P evd，V2G (t)η DC-DC

[0026] Among them, PV2G (t) represents the actual discharge amount of the electric vehicle cluster participating in the V2G orderly discharge mode in the current building in the tth period; P evd，V2G (t) represents the available discharge capacity of the electric vehicle cluster participating in the V2G orderly discharge mode in the current building in the tth period; η DC-DC Indicates the conversion efficiency of the DC-DC converter.

[0027] Preferably, the step of determining the discharge order of the electric vehicle cluster participating in orderly discharge in each building in each time period according to the electric vehicle discharge time model comprises:

[0028] After obtaining the start discharge time of each electric vehicle in the electric vehicle cluster participating in orderly discharge in each building according to the electric vehicle discharge time model, determine the order in which each electric vehicle in the electric vehicle cluster participating in orderly discharge in each building performs orderly discharge on the building under its corresponding discharge mode;

[0029] The electric vehicle discharge time model is:

[0030]

[0031] Among them, t d Indicates the charging time of electric vehicles; SOC evin Indicates the state of charge value of the electric vehicle when it arrives home; SOC evmin Indicates the minimum state of charge threshold of electric vehicles; t ps ,t pe They represent the start and end time of the peak electricity price period; t1 represents the time when the electric vehicle returns home; t vs ,t ve Respectively represent the start time and end time of the electricity price valley period; t out Indicates the time when the electric vehicle leaves home the next day; SOC eve It represents the state of charge value of the electric vehicle that the owner expects when the electric vehicle leaves home the next day; Q ev Indicates the battery capacity of electric vehicles; p evd Indicates the discharge power of the electric vehicle; p evc Represents the charging power of the electric vehicle; η evd Represents the discharge efficiency of electric vehicles; η evc represents the charging efficiency of electric vehicles; k represents a random number in the interval [0, 1]; t dis Indicates the start discharge time of the electric vehicle.

[0032] Preferably, in each building in each time period, the electric vehicle cluster whose arrival time is during the peak electricity price period and whose charge state value when arriving home is greater than the minimum charge state threshold value is orderly discharged during the peak electricity price period and then orderly charged during the valley electricity price period; in each building in each time period, the electric vehicle cluster whose arrival time is during the peak electricity price period and whose charge state value when arriving home is less than or equal to the minimum charge state threshold value is directly orderly charged during the valley electricity price period; in each building in each time period, the electric vehicle cluster whose arrival time is during the valley electricity price period is directly orderly charged during the valley electricity price period; wherein, the electric vehicle cluster that is orderly charged during the valley electricity price period in each building in each time period is regarded as the electric vehicle cluster that participates in orderly charging in each building in each time period.

[0033] Preferably, the process of determining the charging order of the electric vehicle cluster participating in the orderly charging in each building in each time period includes:

[0034] According to the electric vehicle charging time model, after obtaining the start charging time of each electric vehicle in the electric vehicle cluster participating in orderly charging in each building, determine the order of orderly charging of each electric vehicle in the electric vehicle cluster participating in orderly charging in each building at the beginning of the electricity price valley period;

[0035] The electric vehicle charging time model is:

[0036]

[0037] Among them, t c Indicates the charging time of electric vehicles; t d Indicates the discharge time of the electric vehicle; p evd Indicates the discharge power of the electric vehicle; p evc Represents the charging power of the electric vehicle; η evc Indicates the charging efficiency of electric vehicles; SOC evin Indicates the state of charge value of the electric vehicle when it arrives home; SOC eve It represents the state of charge value of the electric vehicle that the owner expects when the electric vehicle leaves home the next day; Q ev Indicates the battery capacity of electric vehicles; T stay represents the time that electric vehicles stay in the electricity price valley period; t out represents the time when the electric car leaves home the next day; t vs ,t ve Respectively represent the start time and end time of the electricity price valley period; t start represents the start charging time of the electric vehicle; k represents a random number in the interval [0, 1].

[0038] Preferably, the battery loss cost generated by charging and discharging electric vehicles in each building based on the electric vehicle battery loss model includes:

[0039] The electric vehicle battery loss model includes an electric vehicle state of charge loss model and an electric vehicle discharge depth loss model;

[0040] The expression of the electric vehicle state of charge loss model is:

[0041]

[0042] Among them, C SOC (t) represents the loss cost of the state of charge of the electric vehicle in the tth period; C0 represents the cost of purchasing the electric vehicle battery; SOC(t) represents the state of charge value of the electric vehicle in the tth period; α represents the first linear processing data; β represents the second linear processing data; CF max Indicates the maximum capacity attenuation constant of the battery; T Ω Indicates the service life of electric vehicle batteries; T D Indicates the preset time; d indicates the time interval;

[0043] The expression of the electric vehicle discharge depth loss model is:

[0044]

[0045] Among them, C DOD Indicates the loss cost of the electric vehicle's discharge depth; N represents the number of discharge cycles in a day; ΔL D0D (m) represents the discharge depth of the mth discharge cycle; f(ΔL DOD (m)) represents ΔL DOD (m) corresponding battery cycle life; ω1, ω2, ω3, ω4, ω5 represent the first coefficient, the second coefficient, the third coefficient, the fourth coefficient, and the fifth coefficient, respectively;

[0046] The battery loss cost C generated by charging and discharging electric vehicles in the i-th building ev，i The expression is:

[0047]

[0048] in, represents the loss cost of the electric vehicle charge state in the i-th building in the t-th period; represents the loss cost of the electric vehicle discharge depth in the i-th building in the t-th period; T represents the total number of periods, T = T D / d.

[0049] Preferably, the electric vehicle constraint condition is always satisfied during the charging and discharging process of the electric vehicle, and the expression of the electric vehicle constraint condition is:

[0050] SOCevmin ≤SOC ev (t)≤SOC evmax

[0051] Among them, SOC evmin Indicates the minimum state of charge threshold of electric vehicles; SOC ev (t) represents the state of charge value of the electric vehicle in the tth period; SOC evmax Indicates the maximum state of charge threshold of an electric vehicle.

[0052] The above technical solution of the present invention has the following beneficial effects compared with the prior art:

[0053] The residential energy optimization control method based on V2B, V2G and electric energy sharing described in the present invention optimizes the residential area with the minimum energy consumption cost of each building as the goal; designs three discharge modes of V2B, V2G, and electric vehicle-building electric energy sharing, and judges whether the electric vehicle enters the discharge mode and which discharge mode it participates in according to the time when the electric vehicle returns home and the charge state of the electric vehicle when it returns home; calculates the discharge time of each electric vehicle and the time to start discharging according to the electric vehicle discharge time model, so that each electric vehicle can discharge in an orderly manner during the peak electricity price period; at the same time, calculates the charging time of each electric vehicle according to the electric vehicle charging time model. The charging time and the time to start charging are taken into consideration so that each electric vehicle can be charged in an orderly manner during the electricity price valley period; this method considers linking electric vehicles with all buildings and power grids in the entire community to exchange electricity, and providing electricity to buildings through electric vehicle discharge, thereby reducing electricity costs between buildings and alleviating the pressure on the power grid; in addition, the charging and discharging of electric vehicles are guided in an orderly manner, and the electric vehicle (V2B, V2G)-residential area-power grid interaction mode is used to assist in peak load regulation, reduce the load peak-valley difference, improve the power grid operation efficiency and reliability, and reduce the power grid's investment in distribution network construction; at the same time, the charging needs of users are met, and car owners can obtain electric vehicle discharge income and reduce their electricity purchase expenses. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein:

[0055] Figure 1 It is a flow chart of a residential energy optimization control method based on V2B, V2G and power sharing provided by the present invention;

[0056] Figure 2 It is a framework diagram of energy management operation in residential areas;

[0057] Figure 3is the charging load bar chart of electric vehicles in building A before and after optimization; Figure 3 The middle left picture is a bar chart of charging load of electric vehicles in Building A before optimization; Figure 3 The middle right picture is a bar chart of charging load of electric vehicles in Building A after optimization;

[0058] Figure 4 is the charging load bar chart of electric vehicles in building B before and after optimization; Figure 4 The middle left picture is a bar chart of charging load before optimization of electric vehicles in Building B; Figure 4 The middle right picture is a bar chart of the charging load of electric vehicles in Building B after optimization. DETAILED DESCRIPTION

[0059] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0060] Reference Figure 1 As shown, Figure 1 The present invention provides a flow chart of a residential energy optimization control method based on V2B, V2G and power sharing; specifically including:

[0061] S1: When an electric vehicle is connected to a building, the electricity price information, the state of charge of the electric vehicle, and the building load are obtained; the electric vehicle clusters in each building in each time period whose arrival time is during the peak electricity price period and whose charge state value when arriving home is greater than the minimum state of charge threshold are obtained, and the electric vehicle clusters participating in orderly discharge in each building in each time period are obtained;

[0062] S2: According to the electric vehicle discharge time model, determine the discharge order of the electric vehicle cluster participating in orderly discharge in each building in each period, including:

[0063] After obtaining the start discharge time of each electric vehicle in the electric vehicle cluster participating in orderly discharge in each building according to the electric vehicle discharge time model, determine the order in which each electric vehicle in the electric vehicle cluster participating in orderly discharge in each building performs orderly discharge on the building under its corresponding discharge mode;

[0064] The electric vehicle discharge time model is:

[0065]

[0066] Among them, t d Indicates the discharge time of electric vehicles; SOC evin Indicates the state of charge value of the electric vehicle when it arrives home; SOC evmin Indicates the minimum state of charge threshold of electric vehicles; t ps ,t peThey represent the start and end time of the peak electricity price period; t1 represents the time when the electric vehicle returns home; t vs ,t ve Respectively represent the start time and end time of the electricity price valley period; t out Indicates the time when the electric vehicle leaves home the next day; SOC eve It represents the state of charge value of the electric vehicle that the owner expects when the electric vehicle leaves home the next day; Q ev Indicates the battery capacity of electric vehicles; p evd Indicates the discharge power of the electric vehicle; p evc Represents the charging power of the electric vehicle; η evd Represents the discharge efficiency of electric vehicles; η evc represents the charging efficiency of electric vehicles; k represents a random number in the interval [0, 1]; t dis Indicates the start discharge time of the electric vehicle;

[0067] S3: If the current building load in the t-th period is greater than zero, the electric vehicle cluster participating in the orderly discharge in the current building in the t-th period enters the V2B orderly discharge mode; based on the constructed electric vehicle V2B discharge model, according to the available discharge capacity of the electric vehicle cluster participating in the V2B orderly discharge mode in the current building in the t-th period, the load capacity of the current building in the t-th period, and the electric vehicle discharge efficiency, the actual discharge capacity of the electric vehicle cluster participating in the V2B orderly discharge mode in the current building in the t-th period is obtained;

[0068] The constructed electric vehicle V2B discharge model is:

[0069] P V2B (t) = min{P evd，V2B (t)η evd η AC-DC , P L (t)}

[0070] Among them, P V2B (t) represents the actual discharge amount of the electric vehicle cluster participating in the V2B orderly discharge mode in the current building in the tth period; P L (t) represents the current building load in the tth period; P evd，V2B (t) represents the available discharge capacity of the electric vehicle cluster participating in the V2B orderly discharge mode in the current building in the tth period; η evd Represents the discharge efficiency of electric vehicles; η AC-DC Indicates the conversion efficiency of AC-DC converter;

[0071] S4: If the current building load in the t-th period is equal to zero, and the load of other buildings in the residential area is greater than zero, then the electric vehicle cluster participating in the orderly discharge of the current building in the t-th period enters the electric energy sharing orderly discharge mode, and the current building is regarded as the surplus power building; all buildings in the residential area with a load equal to zero in the t-th period are regarded as the surplus power building cluster, and all buildings with a load greater than zero are regarded as the power-deficient building cluster; based on the constructed electric vehicle-building power sharing model, according to the available discharge capacity of all electric vehicle clusters participating in the electric energy sharing orderly discharge mode in the surplus power building cluster in the t-th period and the load capacity of the power-deficient building cluster in the t-th period, the actual discharge capacity of all electric vehicle clusters participating in the electric energy sharing orderly discharge mode in the surplus power building cluster in the t-th period is obtained; the dispatching control center obtains the actual discharge capacity of each surplus power building in the t-th period through the load capacity and available discharge capacity of each surplus power building in the t-th period;

[0072] The constructed electric vehicle-building power sharing model is:

[0073] P ev,TSP (t) = P sell,TSP (t) = P buy,TBP (t) = min{P TBP (t), P evd,TSP (t)η DC-AC}

[0074] Among them, P ev，TSP (t) represents the actual discharge capacity of all electric vehicle clusters participating in the orderly discharge mode of power sharing in the surplus power building cluster in the tth period; P TBP (t) represents the load of the power-deficient building cluster in the tth period; P evd,TSP (t) represents the available discharge capacity of all electric vehicle clusters participating in the orderly discharge mode of power sharing in the surplus power building cluster in the tth period; η DC-AC Indicates the conversion efficiency of DC-AC converter; P sell,TSP (t) represents the electricity sold by the surplus power building cluster; P buy,TBP (t) represents the purchased electricity energy of the power-deficient building cluster;

[0075] S5: If the load of all buildings in the residential area is zero in the tth period, the electric vehicle cluster participating in the orderly discharge of the current building in the tth period enters the V2G orderly discharge mode; based on the constructed electric vehicle V2G discharge model, according to the available discharge capacity and electric vehicle discharge efficiency of the electric vehicle cluster participating in the V2G orderly discharge mode in the current building in the tth period, the actual discharge capacity of the electric vehicle cluster participating in the V2G orderly discharge mode in the current building in the tth period is obtained;

[0076] The constructed electric vehicle V2G discharge model is:

[0077] P V2G (t) = P evd,V2G (t)η DC-DC

[0078] Among them, P V2G (t) represents the actual discharge amount of the electric vehicle cluster participating in the V2G orderly discharge mode in the current building in the tth period; P evd,V2G (t) represents the available discharge capacity of the electric vehicle cluster participating in the V2G orderly discharge mode in the current building in the tth period; η DC-DC Indicates the conversion efficiency of DC-DC converter;

[0079] S6: In each building in each time period, the electric vehicle cluster whose arrival time is during the peak electricity price period and whose charge state value when arriving home is greater than the minimum charge state threshold value is discharged in an orderly manner during the peak electricity price period, and then is charged in an orderly manner during the valley electricity price period; in each building in each time period, the electric vehicle cluster whose arrival time is during the peak electricity price period and whose charge state value when arriving home is less than or equal to the minimum charge state threshold value is directly charged in an orderly manner during the valley electricity price period; in each building in each time period, the electric vehicle cluster whose arrival time is during the valley electricity price period is directly charged in an orderly manner during the valley electricity price period; wherein, the electric vehicle cluster that is charged in an orderly manner during the valley electricity price period in each building in each time period is regarded as the electric vehicle cluster that participates in orderly charging in each building in each time period;

[0080] S7: The process of determining the charging order of the electric vehicle cluster participating in the orderly charging in each building in each period includes:

[0081] According to the electric vehicle charging time model, after obtaining the start charging time of each electric vehicle in the electric vehicle cluster participating in orderly charging in each building, determine the order of orderly charging of each electric vehicle in the electric vehicle cluster participating in orderly charging in each building at the beginning of the electricity price valley period;

[0082] The electric vehicle charging time model is:

[0083]

[0084] Among them, t c Indicates the charging time of electric vehicles; t d Indicates the discharge time of the electric vehicle; p evd Indicates the discharge power of the electric vehicle; p evc Represents the charging power of the electric vehicle; η evc Indicates the charging efficiency of electric vehicles; SOC evin Indicates the state of charge value of the electric vehicle when it arrives home; SOC eveIt represents the state of charge value of the electric vehicle that the owner expects when the electric vehicle leaves home the next day; Q ev Indicates the battery capacity of electric vehicles; T stay represents the time that electric vehicles stay in the electricity price valley period; t out represents the time when the electric car leaves home the next day; t vs ,t ve Respectively represent the start time and end time of the electricity price valley period; T start represents the start charging time of the electric vehicle; k represents a random number in the interval [0, 1];

[0085] S8: Based on the electric vehicle battery loss model, the battery loss costs caused by charging and discharging electric vehicles in each building are obtained, including:

[0086] The electric vehicle battery loss model includes an electric vehicle state of charge loss model and an electric vehicle discharge depth loss model;

[0087] The expression of the electric vehicle state of charge loss model is:

[0088]

[0089] Among them, C SOC (t) represents the loss cost of the state of charge of the electric vehicle in the tth period; C0 represents the cost of purchasing the electric vehicle battery; SOC(t) represents the state of charge value of the electric vehicle in the tth period; α represents the first linear processing data; β represents the second linear processing data; CF max Indicates the maximum capacity attenuation constant of the battery; T Ω Indicates the service life of electric vehicle batteries; T D Indicates the preset time; d indicates the time interval;

[0090] In a specific embodiment of the present invention, the service life of the electric vehicle battery is T s 15 years; preset time T D is 24 hours; the time interval d is 30 minutes;

[0091] The expression of the electric vehicle discharge depth loss model is:

[0092]

[0093] Among them, C DOD Indicates the loss cost of the electric vehicle's discharge depth; N represents the number of discharge cycles; ΔL DOD (m) represents the discharge depth of the mth discharge cycle; f(ΔL DOD (m)) represents ΔL DOD(m) corresponding battery cycle life; ω1, ω2, ω3, ω4, ω5 represent the first coefficient, the second coefficient, the third coefficient, the fourth coefficient, and the fifth coefficient, respectively;

[0094] In a specific embodiment of the present invention, ω1=1.06, ω2=-2.08; ω3=2.66; ω4=-1.07, ω5=1.07;

[0095] The battery loss cost C generated by charging and discharging electric vehicles in the i-th building ev，i The expression is:

[0096]

[0097] in, represents the loss cost of the electric vehicle charge state in the i-th building in the t-th period; represents the loss cost of the electric vehicle discharge depth in the i-th building in the t-th period; T represents the total number of periods, T = T D / d;

[0098] S9: according to the actual discharge amount of the electric vehicle cluster participating in each discharge mode of each building in each period within the preset time, the load amount of each building in each period, the electricity sales price and the electricity purchase price based on the time-of-use electricity price, the cost of purchasing grid electricity and the cost of electric vehicle discharge electricity for each building in each period within the preset time are obtained, and the battery loss cost generated by the charging and discharging of electric vehicles in each building is combined to obtain the minimum value of the energy consumption cost of each building;

[0099] The expression for the minimum value of the energy consumption cost of each building is:

[0100]

[0101] Where fi represents the energy consumption cost of the i-th building; T represents the total number of time periods; t represents the t-th time period; Δt represents the time interval; λ sell , buy The electricity price of electric vehicle discharge adopts the electricity price of time-of-use electricity price λ sell ;p g，i (t) indicates the purchase of grid electricity by the i-th building in the t-th period; p evd，i (t) represents the electric energy discharged by the electric vehicle purchased by the i-th building in the t-th period; C ev，i represents the battery loss cost caused by charging and discharging of electric vehicles in the i-th building;

[0102] The dispatching control center obtains the electric energy discharged by each building in each period through the actual discharge amount of the electric vehicle cluster participating in each discharge mode in each building in each period within the preset time and the load amount of each building in each period, including:

[0103] In the V2B orderly discharge mode, the electric energy discharged by the electric vehicle purchased by the i-th building in the t-th period is the actual discharge amount of the electric vehicle cluster participating in the V2B orderly discharge mode in the i-th building in the t-th period;

[0104] In the electric energy sharing orderly discharge mode, if the i-th building in the t-th period is a surplus power building, the electric energy discharged by the i-th building in the t-th period is zero; if the i-th building in the t-th period is a power-deficient building, the dispatching control center is used to obtain the electric energy discharged by the i-th building in the t-th period through the load and available discharge capacity of each power-deficient building;

[0105] In the V2G orderly discharge mode, the electric energy discharged by the electric vehicle purchased by the i-th building in the t-th period is zero;

[0106] The expression of the minimum value of the energy consumption cost of each building includes the cost of the building purchasing power from the grid and the electric vehicle discharge power (V2B mode, V2G mode, and inter-building power sharing mode), as well as the battery loss cost; Figure 2 The residential energy management operation framework shown can show the process of energy transfer in the residential area;

[0107] The electric vehicle constraint condition is always satisfied during the charging and discharging process of the electric vehicle. The expression of the electric vehicle constraint condition is:

[0108] SOC evmin ≤SOC ev (t)≤SOC evmax

[0109] Among them, SOC evmin Indicates the minimum state of charge threshold of electric vehicles; SOC ev (t) represents the state of charge value of the electric vehicle in the tth period; SOC evmax Indicates the maximum state of charge threshold of an electric vehicle.

[0110] Based on S2 and S6, if any electric vehicle arrives home during the peak electricity price period, and the state of charge value of the current electric vehicle when it arrives home is greater than the minimum state of charge threshold of the electric vehicle, that is, SOC evin >SOC evmin , then the current electric vehicle meets the discharge requirements, that is, the current electric vehicle will discharge in an orderly manner during the peak electricity price period and charge in an orderly manner during the valley electricity price period, and the start discharge time of the electric vehicle can be known based on the electric vehicle discharge time model;

[0111] If any electric vehicle arrives home during the peak electricity price period, and the state of charge of the current electric vehicle when it arrives home is less than or equal to the minimum state of charge threshold of the electric vehicle, then the current electric vehicle does not meet the discharge requirements, that is, the discharge time of the electric vehicle t d is 0, that is, SOC evin ≤SOC evmin When t d =0; currently, the car will be charged in an orderly manner directly during the electricity price valley period;

[0112] If any electric car arrives home during the electricity price valley period, the current car will be charged in an orderly manner directly during the electricity price valley period;

[0113] In summary, electric vehicles will respond to time-of-use electricity prices and participate in the optimal scheduling of electric vehicle charging and discharging; if the electric vehicle's return home time is before the end time of the peak electricity price period, it will be determined whether the electric vehicle participates in the V2B and V2G discharge plans during the peak electricity price period; if the electric vehicle arrives home during the valley electricity price period, it will directly participate in the orderly charging optimization scheduling;

[0114] If the electric vehicles meet the discharge requirements during the peak period, the electric vehicles will be guided to discharge in an orderly manner. There are three modes for orderly discharge of electric vehicles, namely, electric vehicle V2B mode, electric vehicle-residential building power sharing mode, and electric vehicle V2G mode;

[0115] If the building where the electric vehicle is located needs to purchase electricity (there is electricity demand, that is, the building load is greater than zero) during the current period, the electric vehicle discharges to the building where it is located, that is, the electric vehicle enters the V2B orderly discharge mode; if the building where the electric vehicle is located does not need to purchase electricity during the current period (there is no electricity demand, that is, the building load is equal to zero), and other buildings in the residential area need to purchase electricity, the electric vehicle discharges to the power-deficient building in the residential area, that is, the electric vehicle enters the electric vehicle-building energy sharing orderly discharge mode; if all buildings in the residential area do not need to purchase electricity during the current period, the electric vehicle's surplus electricity is connected to the grid, that is, the electric vehicle enters the V2G orderly discharge mode;

[0116] The charge state of the electric vehicle is obtained when the electric vehicle is connected to the charging pile; based on the charge state of each electric vehicle, the discharge time of each electric vehicle can be calculated, and the discharge time of each electric vehicle is fixed; the discharge amount of the electric vehicle can be used for V2B, inter-building sharing, and V2G. At the same time, the electric vehicle is only discharged in the parking space according to the scheduling procedure, and the destination of the discharged electric energy is determined according to the building's electricity demand and the design priority; based on the electric vehicle discharge time model, the start discharge time of each electric vehicle is determined in order to optimize the scheduling, which can improve the efficiency of electric vehicle discharge to a greater extent.

[0117] In short, by guiding the orderly charging and discharging of electric vehicles, the energy consumption costs of buildings can be reduced and minimized.

[0118] The present invention constructs an orderly charging and discharging model for electric vehicles, and optimizes it with the goal of minimizing the energy consumption cost of buildings in residential areas. By orderly guiding the charging and discharging of electric vehicles, the peak load demand can be effectively reduced, saving residents' electricity expenses. Electric vehicles participating in V2B can directly supply electricity to buildings, maximizing user benefits. If more electric vehicles can be encouraged to participate in V2B, more electricity purchase costs will be saved for buildings. By sharing electricity between buildings, the electricity expenditure of buildings can be reduced. By connecting electric vehicles to the grid through V2B, the efficiency and reliability of the power grid operation can be improved, while reducing the power grid's investment in distribution network construction.

[0119] Based on S1-S9, the present invention studies two buildings, A and B, assuming that each building has 100 residents, building A has 80 electric vehicles, and building B has 60 electric vehicles; assuming that the battery capacity of electric vehicles is evenly distributed in the range of 20-30kW·h, the rated charge and discharge power is 4kW, the charge and discharge efficiency is 0.95, the battery cost is 96,000 yuan, and the user's expectations when the electric vehicle leaves home; 30 minutes is a time period; a total of 48 time periods throughout the day are optimized and scheduled. In the MATLAB2018a platform, CPLEX12.7 is called by YALM IP to solve the example; the example settings are shown in Table 1;

[0120] Table 1 Example settings

[0121] Calculation example Electric vehicle charging and discharging Power sharing Example 1 Disorder Not Shared Example 2 Orderly Not Shared Example 3 Orderly shared

[0122] Benefit 1: Improved grid reliability

[0123] pass Figure 3 , Figure 4 It can be seen that after optimization, the charging load of electric vehicles during peak hours can be significantly reduced (the charging load of building A is reduced to 57.7%, and the charging load of building B is reduced to 68.6%), which effectively improves the reliability of the power grid.

[0124] Effect 2: Saving residents’ electricity costs

[0125] The electricity purchase cost results of each example are shown in Table 2. It can be seen from Table 2 that the results of Example 1 and Example 3 prove that the present invention can reduce the electricity purchase cost to 47.9%, and the saved electricity purchase cost is much greater than the loss of battery charging and discharging, which proves that the optimization strategy has actual economic benefits.

[0126] Table 2 Example results

[0127]

[0128] Obviously, the above embodiments are merely examples for the purpose of clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the present invention.

Claims

1. A residential energy optimization control method based on V2B, V2G and power sharing, characterized in that: include: Obtain the electric vehicle clusters in each building in each time period whose arrival time is during the peak electricity price period and whose charge state value when arriving home is greater than the minimum charge state threshold, and obtain the electric vehicle clusters participating in orderly discharge in each building in each time period; According to the electric vehicle discharge time model, the discharge order of the electric vehicle cluster participating in orderly discharge in each building in each period is determined; If the current building load in the t-th period is greater than zero, the electric vehicle cluster participating in the orderly discharge in the current building in the t-th period enters the V2B orderly discharge mode; based on the constructed electric vehicle V2B discharge model, the actual discharge amount of the electric vehicle cluster participating in the V2B orderly discharge mode in the current building in the t-th period is obtained; If the load of the current building in the tth period is equal to zero, and the load of other buildings in the residential area is greater than zero, then the electric vehicle cluster participating in the orderly discharge of the current building in the tth period enters the electric energy sharing orderly discharge mode, and the current building is regarded as the surplus power building; All buildings with zero load in the residential area in the t-th period are regarded as surplus power building clusters, and all buildings with load greater than zero are regarded as power-deficient building clusters; based on the constructed electric vehicle-building power sharing model, the actual discharge capacity of all electric vehicle clusters participating in the power sharing orderly discharge mode in the surplus power building cluster in the t-th period is obtained; the dispatching control center obtains the actual discharge capacity of each surplus power building in the t-th period through the load capacity and available discharge capacity of each surplus power building in the t-th period; If the load of all buildings in the residential area is zero in the tth period, the electric vehicle cluster participating in the orderly discharge of the current building in the tth period enters the V2G orderly discharge mode; based on the constructed electric vehicle V2G discharge model, the actual discharge amount of the electric vehicle cluster participating in the V2G orderly discharge mode in the current building in the tth period is obtained; Based on the electric vehicle battery loss model, the battery loss cost caused by charging and discharging electric vehicles in each building is obtained; According to the actual discharge amount of the electric vehicle cluster participating in each discharge mode in each building in each period within the preset time, the load of each building in each period, and the electricity sales price and electricity purchase price based on the time-of-use electricity price, the minimum value of the grid electricity purchase cost and electric vehicle discharge electricity cost of each building in each period within the preset time is obtained, and then combined with the battery loss cost generated by the charging and discharging of electric vehicles in each building, the minimum energy consumption cost of each building is obtained.

2. A residential energy optimization control method based on V2B, V2G and power sharing according to claim 1, characterized in that: The expression for the minimum value of the energy consumption cost of each building is: Among them, f i represents the energy consumption cost of the i-th building; T D represents the preset time; t represents the tth period; Δt represents the time interval; λ sell , buy The electricity price of electric vehicle discharge adopts the electricity price of time-of-use electricity price λ sell ;p g,i (t) indicates the purchase of grid electricity by the i-th building in the t-th period; p evd,i (t) represents the electric energy discharged by the electric vehicle purchased by the i-th building in the t-th period; C ev,i represents the battery loss cost caused by charging and discharging of electric vehicles in the i-th building; The dispatching and control center obtains the electric energy discharged by electric vehicles purchased by each building in each period through the actual discharge amount of the electric vehicle cluster participating in each discharge mode in each building in each period within the preset time and the load amount of each building in each period.

3. A residential energy optimization control method based on V2B, V2G and power sharing according to claim 1, characterized in that: The constructed electric vehicle V2B discharge model is: P V2B (t)=min{P evd,V2B (t)h evd or AC-DC ,P L (t)} Among them, P V2B (t) represents the actual discharge amount of the electric vehicle cluster participating in the V2B orderly discharge mode in the current building in the tth period; P L (t) represents the current building load in the tth period; P evd,V2B (t) represents the available discharge capacity of the electric vehicle cluster participating in the V2B orderly discharge mode in the current building in the tth period; η evd Represents the discharge efficiency of electric vehicles; η AC-DC Indicates the AC-DC converter conversion efficiency.

4. A residential energy optimization control method based on V2B, V2G and power sharing according to claim 1, characterized in that: The constructed electric vehicle-building power sharing model is: P ev,TSP (t)=min{P TBP (t),P evd,TSP (t)η DC-AC } Among them, P ev,TSP (t) represents the actual discharge capacity of all electric vehicle clusters participating in the orderly discharge mode of power sharing in the surplus power building cluster in the tth period; P TBP (t) represents the load of the power-deficient building cluster in the tth period; P evd,TSP (t) represents the available discharge capacity of all electric vehicle clusters participating in the orderly discharge mode of power sharing in the surplus power building cluster in the tth period; η DC-AC Indicates the DC-AC converter conversion efficiency.

5. The residential energy optimization control method based on V2B, V2G and power sharing according to claim 1 is characterized in that: The constructed electric vehicle V2G discharge model is: P V2G (t)=P evd,V2G (t)η DC-DC Among them, P V2G (t) represents the actual discharge amount of the electric vehicle cluster participating in the V2G orderly discharge mode in the current building in the tth period; P evd,V2G (t) represents the available discharge capacity of the electric vehicle cluster participating in the V2G orderly discharge mode in the current building in the tth period; η DC-DC Indicates the conversion efficiency of the DC-DC converter.

6. A residential energy optimization control method based on V2B, V2G and power sharing according to claim 1, characterized in that: Determining the discharge order of the electric vehicle cluster participating in orderly discharge in each building in each time period according to the electric vehicle discharge time model includes: After obtaining the start discharge time of each electric vehicle in the electric vehicle cluster participating in orderly discharge in each building according to the electric vehicle discharge time model, determine the order in which each electric vehicle in the electric vehicle cluster participating in orderly discharge in each building performs orderly discharge on the building under its corresponding discharge mode; The electric vehicle discharge time model is: Among them, t d Indicates the charging time of electric vehicles; SOC evin Indicates the state of charge value of the electric vehicle when it arrives home; SOC evmin Indicates the minimum state of charge threshold of electric vehicles; t ps ,t pe They represent the start and end time of the peak electricity price period; t1 represents the time when the electric vehicle returns home; t vs ,t ve Respectively represent the start time and end time of the electricity price valley period; t out Indicates the time when the electric vehicle leaves home the next day; SOC eve Q represents the state of charge value of the electric vehicle that the owner expects when the electric vehicle leaves home the next day; ev Indicates the battery capacity of electric vehicles; p evd Indicates the discharge power of the electric vehicle; p evc Represents the charging power of the electric vehicle; η end Represents the discharge efficiency of electric vehicles; η evc represents the charging efficiency of electric vehicles; k represents a random number in the interval [0,1]; t dis Indicates the start discharge time of the electric vehicle.

7. The residential energy optimization control method based on V2B, V2G and power sharing according to claim 1 is characterized in that: In each building in each time period, the electric vehicle cluster whose arrival time is during the peak electricity price period and whose charge state value when arriving home is greater than the minimum charge state threshold will be discharged in an orderly manner during the peak electricity price period, and then charged in an orderly manner during the valley electricity price period; in each building in each time period, the electric vehicle cluster whose arrival time is during the peak electricity price period and whose charge state value when arriving home is less than or equal to the minimum charge state threshold will be charged in an orderly manner directly during the valley electricity price period; in each building in each time period, the electric vehicle cluster whose arrival time is during the valley electricity price period will be charged in an orderly manner directly during the valley electricity price period; among them, the electric vehicle cluster that is charged in an orderly manner during the valley electricity price period in each building in each time period will be regarded as the electric vehicle cluster that participates in orderly charging in each building in each time period.

8. A residential energy optimization control method based on V2B, V2G and power sharing according to claim 7, characterized in that: The process of determining the charging order of the electric vehicle cluster participating in orderly charging in each building in each period includes: According to the electric vehicle charging time model, after obtaining the start charging time of each electric vehicle in the electric vehicle cluster participating in orderly charging in each building, determine the order of orderly charging of each electric vehicle in the electric vehicle cluster participating in orderly charging in each building at the beginning of the electricity price valley period; The electric vehicle charging time model is: Among them, t c Indicates the charging time of electric vehicles; t d Indicates the discharge time of the electric vehicle; p evd Indicates the discharge power of the electric vehicle; p evc Represents the charging power of the electric vehicle; η evc Indicates the charging efficiency of electric vehicles; SOC evin Indicates the state of charge value of the electric vehicle when it arrives home; SOC eve It represents the state of charge value of the electric vehicle that the owner expects when the electric vehicle leaves home the next day; Q ev Indicates the battery capacity of electric vehicles; T stay represents the time that electric vehicles stay in the electricity price valley period; t out represents the time when the electric car leaves home the next day; t vs ,t ve Respectively represent the start time and end time of the electricity price valley period; t start represents the start charging time of the electric vehicle; k represents a random number in the interval [0,1].

9. The residential energy optimization control method based on V2B, V2G and power sharing according to claim 1 is characterized in that: Based on the electric vehicle battery loss model, the battery loss costs generated by charging and discharging electric vehicles in each building include: The electric vehicle battery loss model includes an electric vehicle state of charge loss model and an electric vehicle discharge depth loss model; The expression of the electric vehicle state of charge loss model is: Among them, C SOC (t) represents the loss cost of the state of charge of the electric vehicle in the tth period; C0 represents the cost of purchasing the electric vehicle battery; SOC(t) represents the state of charge value of the electric vehicle in the tth period; α represents the first linear processing data; β represents the second linear processing data; CF max Indicates the maximum capacity attenuation constant of the battery; T s Indicates the service life of electric vehicle batteries; T D Indicates the preset time; d indicates the time interval; The expression of the electric vehicle discharge depth loss model is: f(ΔL DOD (m)) =[ω1(ΔL DOD (m)) 4 +ω2(ΔL DOD (m)) 3 +ω3(ΔL DOD (m)) 2 +ω4(ΔL DOD (m))+ω5]·10 5 Among them, C DOD Indicates the loss cost of the electric vehicle's discharge depth; N represents the number of discharge cycles in a day; ΔL DOD (m) represents the discharge depth of the mth discharge cycle; f(ΔL DOD (m)) represents ΔL DOD (m) corresponding battery cycle life; ω1, ω2, ω3, ω4, ω5 represent the first coefficient, the second coefficient, the third coefficient, the fourth coefficient, and the fifth coefficient, respectively; The battery loss cost C generated by charging and discharging electric vehicles in the i-th building ev,i The expression is: in, represents the loss cost of the electric vehicle charge state in the i-th building in the t-th period; represents the loss cost of the electric vehicle discharge depth in the i-th building in the t-th period; T represents the total number of periods, T = T D / d.

10. A residential energy optimization control method based on V2B, V2G and power sharing according to claim 1, characterized in that: The electric vehicle constraint condition is always satisfied during the charging and discharging process of the electric vehicle. The expression of the electric vehicle constraint condition is: SOC evmin ≤SOC ev (t)≤SOC evmax Among them, SOC evmin Indicates the minimum state of charge threshold of electric vehicles; SOC ev (t) represents the state of charge value of the electric vehicle in the tth period; SOC evmax Indicates the maximum state of charge threshold of an electric vehicle.

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