Electric bus charging and discharging combined scheduling method

Abstract

The invention discloses an electric bus charging and discharging combined scheduling method, and belongs to the field of intelligent bus scheduling. The method comprises the following steps: firstly, collecting an operation plan and time-of-use electricity price data of an electric bus, and then constructing an electric bus participation vehicle network integration charging and discharging scheduling model which comprehensively considers cost benefits; the model can decide the optimal charging and discharging strategy of each electric bus according to the operation plan and the residual electric quantity of the electric bus and the real-time electricity price of a power grid, so that the bus operation requirement is met, the charging at the electricity price valley period and the discharging at the electricity price peak period can be fully realized, and the charging and discharging efficiency is improved. Therefore, the charging cost is reduced and the electricity selling income is maximized. Through the method, the electric bus not only can meet the requirements of public transportation, but also can participate in peak load shifting of a power grid, efficient utilization of energy and maximization of economic benefits are achieved, and powerful technical support is provided for sustainable development of the electric bus.

Description

Technical Field

[0001] The present invention relates to the technical field of electric demand response bus dispatching considering charging and discharging, and particularly relates to a method for joint dispatching of electric bus charging and discharging. Background Art

[0002] As an important part of urban public transportation, electric buses are an important measure to respond to the call for green travel and alleviate energy shortage. Many regions have successively introduced policies to support the development of electric buses. The popularization and use of electric buses helps to reduce the carbon emissions of urban transportation, can effectively solve the problem of environmental pollution, and promote green transportation and sustainable development. With the support of vehicle-to-grid (V2G) technology, electric buses can not only be consumers of electricity, but also be providers of electricity when necessary, becoming a part of grid load regulation. This two-way interaction with the grid poses higher requirements for the power management of electric buses. How to use the charging and discharging technology of electric buses to bring new benefits to bus operators while meeting the daily operation of buses has become a practical problem faced by the development of electric buses.

[0003] The charging and discharging scheduling method of electric buses effectively decides the timing and amount of charging and discharging of electric buses according to the time-of-use electricity price at the smart grid end, so that electric buses can charge when the grid load is low and the electricity price is low, and discharge when the grid load is high and the electricity price is high, assisting the grid to balance the peak-valley difference and realizing good interaction with the smart grid, thereby reducing the total operating cost of electric buses while meeting the daily operation requirements of buses.

[0004] The existing charging and discharging scheduling methods of electric buses reasonably arrange the vehicle scheduling and charging time of electric buses by analyzing the impact of the charging behavior of electric buses on the grid stability. However, in the existing technology, there are the following deficiencies in the scheduling design methods that simultaneously consider the charging and discharging strategies of electric buses:

[0005] 1. In the existing conventional operation scheduling of electric buses, it is mostly based on fixed charging or discharging prices, and the real-time electricity price of the grid has not been fully considered, so it cannot interact bidirectionally with the smart grid, cannot effectively achieve peak shaving and valley filling, and cannot reduce the impact on the grid load. In practice, the grid implements a time-of-use electricity price strategy, and the time-of-use electricity price should be considered in the charging and discharging strategy decision-making for the cost-benefit of long-term operation and the impact on the economy of bus operation units;

[0006] 2. In the existing research on the charging and discharging of electric buses, the impact of battery loss on the cost has not been fully considered. Since the battery loss is mainly affected by the depth of discharge of the battery, considering the frequent charging and discharging of the power batteries of electric buses in daily operation, the battery loss cost is also an important part of the bus operation cost. The lack of this part will lead to an underestimation of the bus operation cost;

[0007] 3. In the existing charging and discharging scheduling decision-making of electric buses, the full charging and rapid charging strategies are considered, and the charging plan or discharging plan is given priority over the bus operation schedule, making it impossible for the vehicle to closely combine the charging and discharging activities with the daily operation schedule. It may detour to the charging station or discharging station for charging and discharging activities during the driving process, reducing the operation efficiency of electric buses.

[0008] Therefore, on the basis of considering the time-of-use electricity price at the smart grid end and meeting the operation schedule, how to maximize the revenue from selling electricity to the grid, minimize the empty driving cost, charging cost, and battery loss cost of electric bus charging and discharging, and provide a combined charging and discharging scheduling method for electric buses that closely combines the charging and discharging plan with the daily operation plan is an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0009] The present invention provides a combined charging and discharging scheduling method for electric buses. Based on technical means such as V2G technology, Internet of Things technology, and big data technology, it collects the real-time electricity price information of the power grid, combines the charging and discharging plan of electric buses with the daily operation plan through an intelligent scheduling strategy, and decides the optimal charging and discharging strategy for each electric bus to ensure that while meeting the bus operation requirements, it can make full use of the low electricity price period for charging and the peak period for discharging, thereby realizing the minimization of the total cost and the maximization of the revenue from selling electricity, and solving the problems that the existing electric buses cannot flexibly adjust the charging and discharging plan, affect the daily operation schedule, and do not fully consider the battery loss cost, etc.

[0010] To achieve the above object, the technical solution of the present invention is:

[0011] A combined charging and discharging scheduling method for electric buses, comprising the following steps:

[0012] Step 1: Obtain the basic data of the bus company. The basic data of the bus company includes the initial position information of the bus, the start and end position information of each trip, the daily operation schedule, the number of charging piles, and the number of vehicles. The daily operation schedule includes the arrival and departure time information of each trip, the power consumption of each trip, the empty driving distance, and the empty driving power consumption. Construct a total objective function that minimizes the charging cost and maximizes the revenue from selling electricity. Combine the historical operation data of electric buses, which includes the vehicle battery status, trip power consumption, charging and discharging behavior, and daily operation situation data. Then, combine the time-of-use electricity price data to initialize the total objective function, and obtain the initial operation parameters, battery parameters, charging pile parameters, and charging and discharging rates of electric buses.

[0013] Step 2: According to the determined starting and ending points of the trips and the power consumption for completing each trip, generate the initial driving routes for each electric bus under the condition of meeting the battery capacity constraint;

[0014] Step 3: According to the initial driving routes, decide the charging and discharging tasks after the vehicle returns to the depot at the end of the trip, determine whether the vehicle needs to charge or discharge. If no charging or discharging is required, decide whether to proceed to the next trip and the waiting time of the vehicle; if charging or discharging is required, decide the charging and discharging duration of the vehicle and the waiting time of the vehicle;

[0015] Step 4: After implementing the vehicle charging and discharging strategy, according to the battery power situation of each vehicle, combined with the time-of-use electricity price mechanism, optimize the battery power of each vehicle, so that the vehicle charges during the period with low electricity price and discharges during the period with high electricity price, while ensuring that the battery power of each vehicle can complete the next trip. By jointly optimizing the vehicle driving plan and the charging and discharging plan, based on the determined trip operation schedule, generate the trip arrangements corresponding to the determined operation schedule for each electric bus.

[0016] Advantages of the present invention:

[0017] The present invention discloses a combined dispatching method for electric bus charging and discharging. The present invention fully considers the daily operation schedule of electric buses and the charging and discharging requirements, and based on the time-of-use electricity price considering the smart grid, completes the decision-making of the electric bus charging and discharging plan, realizing that on the basis of fully meeting the daily operation requirements, the charging and discharging plan of the vehicle can be reasonably put into operation through dispatching arrangements; the present invention also incorporates the battery loss cost into the bus operation cost, and through the income from reselling electricity to the power grid, balances the charging cost and the battery loss cost in daily operation. It solves the problem of the existing single consideration of the charging plan or the discharging plan and the neglect of the combination of the charging and discharging plan and the daily operation plan, and more efficiently realizes the combination of the charging and discharging plan and the operation plan, achieving the efficient utilization of energy and the maximization of economic benefits. Brief Description of the Drawings

[0018] In order to more clearly illustrate the technical solutions of the present invention, the following will briefly introduce the attached drawings required in the technology of the present invention. Figure 1 Make a simple introduction.

[0019] Figure 1 It is a flowchart of a combined dispatching method for electric bus charging and discharging of the present invention. Detailed Embodiments

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will combine the attached drawings in the embodiments of the present invention. Figure 1, a clear and complete description of the technical solutions in the embodiments of the present invention is given. All other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of the present invention.

[0021] This embodiment provides an electric bus charging and discharging joint scheduling method, as Figure 1 shown, which includes the following steps:

[0022] Step 1: Obtain the basic data of the bus company, where the basic data of the bus company includes the initial position information of the bus, the start and end position information of each trip, the daily operation schedule, the number of charging piles, and the number of vehicles. The daily operation schedule includes the arrival and departure time information of each trip, the power consumption of each trip, the empty driving distance, and the empty driving power consumption. Construct a total objective function that minimizes the charging cost and maximizes the power sales revenue at the same time. Combine the historical operation data of the electric bus, where the historical operation data of the electric bus includes the vehicle battery status, the power consumption of the trip, the charging and discharging behavior, and the daily operation shift arrangement data. Then, combine the time-of-use electricity price data to initialize the total objective function, and obtain the initial electric bus operation parameters, battery parameters, charging pile parameters, and charging and discharging rates.

[0023] The total objective function is specifically:

[0024]

[0025] In the formula, DOC is the total objective function, k represents vehicle k ∈ K, K is the set of vehicles, i represents trip i ∈ I, I is the set of trips, τ represents the time period node, T au represents the set of time periods τ ∈ T au , ω τ is the electricity price for purchasing electricity from the power grid at time period τ, represents the charging duration of vehicle k after completing trip i within time period τ, v τ is the electricity price for selling electricity to the power grid at time period τ, represents the discharging duration of vehicle k after completing trip i within time period τ, ε 1 is the general battery loss parameter, r represents charging pile r ∈ R, R is the set of charging piles, λ r is the discharging power of charging pile r, is a binary variable decision on whether vehicle k uses charging pile r for discharging after completing trip i, is the discharging duration of vehicle k after completing trip i, c r is the fixed cost of the charging pile, N r is a binary variable decision on whether charging pile r is occupied, c k is the fixed maintenance cost to ensure operation, N k is a binary variable decision on whether vehicle k is used.

[0026] Step 2: According to the determined starting and ending points of each trip and the power consumption for completing each trip, generate the initial driving routes for each electric bus under the condition of meeting the battery capacity constraint. The specific steps are as follows:

[0027] Step 2.1: According to the known bus operation schedule, ensure that the starting trip starts from a virtual trip:

[0028]

[0029] In the formula, \(I\) represents the set of actual trips, \(O\) represents the set of virtual starting trips, indicates whether vehicle \(k\) completes trip \(j\) after completing trip \(i\). The value is 1 if vehicle \(k\) completes trip \(i\), and the value is 0 if vehicle \(k\) does not complete trip \(i\) or does not complete trip \(j\) after completing trip \(i\);

[0030] Step 2.2: According to the known bus operation schedule, ensure that the ending trip ends with a virtual trip:

[0031]

[0032] In the formula, indicates whether vehicle \(k\) completes trip \(j\) after completing trip \(i\). The value is 1 if vehicle \(k\) completes trip \(i\), and the value is 0 if vehicle \(k\) does not complete trip \(i\) or does not complete trip \(j\) after completing trip \(i\), and \(V\) represents the set of virtual ending trips;

[0033] Step 2.3: Only one subsequent trip \(j\) is executed for each trip \(i\):

[0034]

[0035] In the formula, \(U\) represents the set of all trips \(U = I\cup O\cup V\), which includes virtual starting trips \(I\), actual trips \(O\), and virtual ending trips \(V\);

[0036] Step 2.4: Only one previous trip \(i\) is executed for each trip \(j\):

[0037]

[0038] Step 2.5: Set the virtual starting trip to ensure that each vehicle has only one departure trip:

[0039]

[0040] In the formula, \(N\) k is a binary variable decision on whether vehicle \(k\) is used. The value is 1 if vehicle \(k\) is used, and the value is 0 if vehicle \(k\) is not used;

[0041] Step 2.6: Set the virtual end trip to ensure that each vehicle has only one end trip:

[0042]

[0043] Step 2.7: Trips are arranged only for vehicles that are in use:

[0044]

[0045] Step 2.8: The vehicle status must be one of the three states: charging and discharging or immediately proceeding to the next trip:

[0047]

[0048] Wherein, is a binary variable to determine whether vehicle k occupies charging pile r for charging after completing trip i, is a binary variable to determine whether vehicle k occupies charging pile r for discharging after completing trip i;

[0049] Step 2.9: Completing a trip is a prerequisite for charging and discharging:

[0050]

[0051] Step 2.10: Flow balance constraint:

[0052]

[0053] Step 2.11: Virtual trips should not have previous trips:

[0054]

[0055] Step 2.12: Virtual trips should not have subsequent trips:

[0056]

[0057] Step 2.13: Sub-path elimination:

[0058]

[0059] Step 2.14: Generate the initial driving route of the electric demand response bus.

[0060] Step 3: According to the initial driving route, decide the charging and discharging tasks of the vehicle after returning to the station after the trip, determine whether the vehicle needs to charge and discharge. If no charging and discharging is required, decide whether to proceed to the next trip and the waiting time of the vehicle; if charging and discharging is required, decide the charging and discharging duration of the vehicle and the waiting time of the vehicle. Specifically, it includes the following steps:

[0061] Step 3.1: Ensure that when a vehicle is charging or discharging, it occupies only one charging pile:

[0062]

[0063] In the formula, is a binary variable to determine whether vehicle k occupies charging pile r for charging after completing trip i, is a binary variable to determine whether vehicle k occupies charging pile r for discharging after completing trip i;

[0064] Step 3.2: Ensure that each charging pile can be used by only one vehicle:

[0065]

[0066] Step 3.3: Calculate the maximum number of charging piles occupied in a day:

[0067]

[0068] In the formula, N r is a binary variable to determine whether charging pile r is occupied, and M represents an infinitely large positive number;

[0069] Step 3.4: A vehicle cannot charge and discharge simultaneously:

[0070]

[0071] Step 3.5: The charging / discharging duration is 0 when no charging / discharging task is performed:

[0072]

[0073] In the formula, is the charging duration of vehicle k after completing trip i, represents the end time of charging of vehicle k after completing trip i, represents the start time of charging of vehicle k after completing trip i, is the discharging duration of vehicle k after completing trip i, represents the end time of discharging of vehicle k after completing trip i, represents the start time of discharging of vehicle k after completing trip i;

[0074] Step 3.6: Time requirements for charging / discharging tasks:

[0075]

[0076]

[0077] Step 3.7: Requirements for the end time of the charge and discharge task:

[0078]

[0079] In the formula, is the start time for vehicle k to execute trip j, and m j is the empty running time from the start and end points of trip j to the station. indicates whether vehicle k completes trip j after completing trip i. The value is 1 if vehicle k completes trip i, and the value is 0 if vehicle k does not complete trip i or does not complete trip j after completing trip i;

[0080] Step 3.8: Constraint on the start time of charge and discharge:

[0081]

[0082] In the formula, m i is the empty running time from the start and end points of trip i to the station. represents the end time for vehicle k to execute trip i;

[0083] Step 3.9: Ensure charging after the last virtual trip ends:

[0084]

[0085] Step 3.10: Start time of charging after the last virtual trip ends:

[0086]

[0087] In the formula, represents the start time of charging for vehicle k after completing trip i, represents the start time of vehicle k executing the virtual end trip.

[0088] Step 4: After implementing the vehicle charge and discharge strategy, based on the battery power of each vehicle and combined with the time-of-use electricity price mechanism, optimize the battery power of each vehicle so that the vehicle charges during low electricity price periods and discharges during high electricity price periods, while ensuring that the battery power of each vehicle can complete the next trip. By jointly optimizing the vehicle driving plan and the charge and discharge plan, based on the determined trip operation schedule, generate the trip arrangements for each electric bus corresponding to the determined operation schedule.

[0089] Furthermore, Step 4 includes ensuring that each vehicle can complete the corresponding trip, and each trip is executed within the specified time. The trip time constraint includes the following steps:

[0090] Step 4.1.1: Vehicle operation meets the requirements for the start time of the trip:

[0091]

[0092] In the formula, represents the start time when vehicle k executes trip i, ST i , represents the start time of trip i;

[0093] Step 4.1.2: The vehicle operation must meet the given trip time requirements:

[0094]

[0095] In the formula, CT i represents the duration of trip i;

[0096] Step 4.1.3: The waiting time requirement before the vehicle makes the next trip:

[0097]

[0098] In the formula, represents the waiting time of vehicle k at the station after completing trip i, m i is the empty running time from the start and end points of trip i to the station, m j is the empty running time from the start and end points of trip j to the station;

[0099] Step 4.1.4: When the vehicle is not operating, the start / end / waiting time of the trip is 0:

[0100]

[0101] Step 4.1.5: Determine the time of the last virtual trip:

[0102]

[0103] In the formula, represents the start time when vehicle k executes the virtual end trip.

[0104] Furthermore, Step 4 includes ensuring that the battery power of each vehicle is sufficient to complete the corresponding trip, and the power constraint includes the following steps:

[0105] Step 4.2.1: Set the battery power of the vehicle to be fully charged at the start of operation every day:

[0106]

[0107] In the formula, represents the power of vehicle k at the start of trip i, E full represents the power when the battery is fully charged;

[0108] Step 4.2.2: Set the battery of the vehicle to be fully charged after each day:

[0109]

[0110] In the formula, represents the remaining battery level of vehicle k after completing trip i;

[0111] Step 4.2.3: Consider the battery to be fully charged when it is charged to over 90%:

[0112] E full = 90% * E max #(42)

[0113] In the formula, E max represents the maximum allowable battery capacity;

[0114] Step 4.2.4: Battery capacity constraint:

[0115]

[0116] In the formula, E min represents the minimum safe battery capacity;

[0117] Step 4.2.5: The vehicle must have enough battery power to complete the corresponding trip:

[0118]

[0119] In the formula, E i represents the power consumption of trip i;

[0120] Step 4.2.6: The battery power for trip j after completing trip i:

[0121]

[0122] In the formula, represents the battery level at the start of trip j for vehicle k, n i represents the power consumption for the empty running distance from the start and end points of trip i to the station, n j represents the power consumption for the empty running distance from the start and end points of trip j to the station, γ r is the charging power of charging pile r;

[0123] Step 4.2.7: The battery power charged after the last virtual trip ends:

[0124]

[0125] Furthermore, Step 4 includes obtaining the optimal driving route and charging and discharging strategy of the electric bus, and calculating the corresponding charging and discharging power constraints within the time-of-use electricity price period, including the following steps:

[0126] Step 4.3.1: Charging duration constraint within the time-of-use electricity price period:

[0127]

[0128] In the formula, represents the charging duration of vehicle k within time period τ after completing trip i, represents whether vehicle k charges within time period τ after completing trip i, Dur τ represents the duration of each time period;

[0129] Step 4.3.2: Total charging duration within the time-of-use electricity price period:

[0130]

[0131] In the formula, is the charging duration of vehicle k after completing trip i;

[0132] Step 4.3.3: Charging auxiliary variable constraint:

[0133]

[0134] Step 4.3.4: Charging-related constraint of auxiliary variable within the time-of-use electricity price period:

[0135]

[0136] In the formula, represents that the start time of charging of vehicle k after completing trip i is greater than the start time of time period τ, represents the start time of charging of vehicle k after completing trip i, represents that the start time of charging of vehicle k after completing trip i is less than the end time of time period τ, Start τ represents the start time of each time period, Dur τ represents the duration of each time period, represents whether vehicle k charges within time period τ after completing trip i;

[0137] Step 4.3.5: Discharging duration constraint within the time-of-use electricity price period:

[0138]

[0139] In the formula, Denote the discharge duration of vehicle k within the time period τ after completing trip i, and Dur represents the duration of each time period. Indicate whether vehicle k discharges within the time period τ after completing trip i

[0140] for discharging;

[0141] Step 4.3.6: Total discharge duration within the time-of-use electricity price section:

[0142]

[0143] Step 4.3.7: Constraints on discharge auxiliary variables:

[0144]

[0145] Step 4.3.8: Constraints related to auxiliary variable discharge within the time-of-use electricity price section:

[0146]

[0147] In the formula, Indicate that the start time of discharging after vehicle k completes trip i is greater than the start time of the time period τ, Indicate the start time of discharging after vehicle k completes trip i, Indicate that the start time of discharging after vehicle k completes trip i is less than the end time of the time period τ, Start τ Indicate the start time of each time period, Dur τ Indicate the duration of each time period, Indicate whether vehicle k discharges within the time period τ after completing trip i.

[0148] To sum up, a scheduling method for electric demand response buses considering the opportunity charging strategy provided by the embodiment of the present invention has the following advantages compared with the prior art:

[0149] 1. Consider the real-time electricity price of the power grid, interact bidirectionally with the smart grid, effectively achieve peak shaving and valley filling, and reduce the impact on the power grid load. Moreover, according to the time-of-use electricity price strategy implemented in the actual power grid, fully consider the cost-benefit of the time-of-use electricity price in the charging and discharging strategy decision-making, and study the impact on the economy of bus operation units;

[0150] 2. Fully consider the impact of battery loss on the cost. Since the battery loss is mainly affected by the depth of discharge of the battery, the present invention takes into account the situation that electric buses need to charge and discharge the battery frequently in daily operation, and includes the battery loss cost as part of the bus operation cost;

[0151] 3. The present invention takes into account the charging plan, the discharging plan and the bus operation schedule, so that when the vehicle conducts charging and discharging activities, it can be closely combined with the daily operation schedule, and there will be no detour to the charging station or the discharging station during driving to conduct charging and discharging activities, thus avoiding the reduction of the operation efficiency of electric buses.

[0152] In summary, the above are only the technical solutions and specific implementation manners of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and all should be covered within the protection scope of the present invention.

Claims

1. A method for combined charging and discharging scheduling of electric buses, characterized in that: The following steps are involved: Step 1: Obtain basic data of the bus company, which includes initial location information of the bus, location information of the starting and ending points of each trip, daily operation schedule, the number of charging piles and the number of vehicles. The daily operation schedule includes arrival and departure time information of each trip, power consumption of each trip, empty driving distance and empty driving power consumption. Construct a total objective function that minimizes charging cost and maximizes electricity sales revenue at the same time. Combined with the historical operation data of the electric bus, the historical operation data of the electric bus includes vehicle battery status, trip power consumption, charging and discharging behavior and daily operation schedule data, and combined with time-of-use electricity price data, initialize the total objective function, and obtain initial electric bus operation parameters, battery parameters, charging pile parameters and charging and discharging rates; Step 2: Based on the determined starting and ending points of the trip and the power consumption of each trip, the initial driving route of each electric bus is generated under the condition that the battery capacity constraint is met; Step 3: Based on the initial driving route, decide the charging and discharging tasks of the vehicle after returning to the station after the trip, determine whether the vehicle needs to be charged and discharged, and if not, decide whether to proceed to the next trip and the waiting time of the vehicle; if charging and discharging is required, decide the duration of charging and discharging of the vehicle and the waiting time of the vehicle; Step 4: After implementing the vehicle charging and discharging strategy, optimize the battery power of each vehicle according to the battery power of each vehicle and the time-of-use electricity price mechanism, so that the vehicle can be charged during the period of low electricity price and discharged during the period of high electricity price. At the same time, ensure that the battery power of each vehicle can complete the next trip. By collaboratively optimizing the vehicle driving plan and charging and discharging plan, based on the determined trip operation schedule, generate a trip schedule for each electric bus corresponding to the determined operation schedule.

2. The method for combined charging and discharging scheduling of electric buses according to claim 1, characterized in that: The overall objective function is specifically: In the formula, DOC is the overall objective function, k represents vehicle k∈K, K is the vehicle set, i represents trip i∈I, I is the trip set, τ represents the time period node, T au Denotes the time period set τ∈T au ,ω τ is the price of electricity purchased from the power grid during the time period τ, represents the charging duration of vehicle k within time period τ after completing trip i, v τ is the electricity price sold to the grid during time period τ, represents the discharge duration of vehicle k in time period τ after completing trip i, ε1 is the general battery loss parameter, r represents the charging pile r∈R, R is the charging pile set, λ r is the discharge power of charging pile r, is a binary variable that determines whether vehicle k occupies charging pile r for discharge after completing trip i. is the duration of discharge after vehicle k completes trip i, c r is the fixed cost of the charging pile, N t is a binary variable that determines whether the charging pile r is occupied, c l To ensure the fixed maintenance cost of operation, N k is a binary variable that determines whether vehicle k is used.

3. The method for combined charging and discharging scheduling of electric buses according to claim 1, characterized in that: Generating the initial driving route of each electric bus in step 2 includes the following steps: Step 2.1: Ensure that the starting trip starts from a virtual trip based on the known bus operation schedule: In the formula, I represents the set of actual trips, O represents the set of virtual starting trips, Indicates whether vehicle k completes trip j after completing trip i. A value of 1 indicates that vehicle k completes trip i, and a value of 0 indicates that vehicle k does not complete trip i or does not complete trip j after completing trip i. Step 2.2: Ensure that the end trip ends with a virtual trip based on the known bus operation schedule: In the formula, Indicates whether vehicle k completes trip j after completing trip i. A value of 1 indicates that vehicle k completes trip i. A value of 0 indicates that vehicle k does not complete trip i or does not complete trip j after completing trip i. V represents the set of virtual end trips. Step 2.3: For each trip i, there is only one subsequent trip j to execute: Where U represents the set of all trips U=I∪O∪V, which includes the virtual starting trip I, the actual trip O and the virtual ending trip V; Step 2.4: Each trip j has only one predecessor trip i to execute: Step 2.5: Set up a virtual starting trip to ensure that each vehicle has only one starting trip: Where N k is a binary variable that determines whether vehicle k is used. The value 1 indicates that vehicle k is used, and the value 0 indicates that vehicle k is not used. Step 2.6: Set up a virtual end trip to ensure that each vehicle has only one end trip: Step 2.7: The vehicle is scheduled only when it is used: Step 2.8: The vehicle status must be one of the following: charging, discharging, or immediately running the next trip: In the formula, is a binary variable that determines whether vehicle k occupies charging post r for charging after completing trip i. It is a binary variable that determines whether vehicle k occupies charging pile r for discharge after completing trip i; Step 2.9: Completing the trip is a prerequisite for charging and discharging: Step 2.10: Flow balance constraints: Step 2.11: Virtual trips should not have a preceding trip: Step 2.12: Virtual trips should not have subsequent trips: Step 2.13: Subpath elimination: Step 2.14: Generate the initial driving route of the electric demand response bus.

4. The method for combined charging and discharging dispatching of electric buses according to claim 1, characterized in that: The charging and discharging tasks after the vehicle returns to the station after the decision-making journey in step 3 include the following steps: Step 3.1: Ensure that a car only occupies one charging pile when charging or discharging: In the formula, is a binary variable that determines whether vehicle k occupies charging post r for charging after completing trip i. It is a binary variable that determines whether vehicle k occupies charging pile r for discharge after completing trip i; Step 3.2: Ensure that each charging station can only be used by one car: Step 3.3: Calculate the maximum number of charging piles occupied in a day: Where N r It is a binary variable that determines whether the charging pile r is occupied, and M represents an infinite positive number; Step 3.4: The vehicle cannot be charged and discharged at the same time: Step 3.5: The charge / discharge duration is 0 when no charge / discharge task is performed: In the formula, The duration of charging after vehicle k completes trip i, represents the end time of charging after vehicle k completes trip i, represents the start time of charging after vehicle k completes trip i, is the duration of discharge after vehicle k completes trip i, represents the end time of discharging after vehicle k completes trip i, represents the start time of discharging after vehicle k completes trip i; Step 3.6: Time requirements for charge and discharge tasks: Step 3.7: Requirements for the end time of the charge and discharge tasks: In the formula, is the starting time of vehicle k to execute trip j, m j is the idle time from the starting point to the terminal of trip j, Indicates whether vehicle k completes trip j after completing trip i. A value of 1 indicates that vehicle k completes trip i, and a value of 0 indicates that vehicle k does not complete trip i or does not complete trip j after completing trip i. Step 3.8: Charge and discharge start time constraints: In the formula, m i is the idle time from the starting point to the terminal of trip i, represents the end time of vehicle k executing trip i; Step 3.9: Ensure charging after the last virtual trip: Step 3.10: Start time of charging after the last virtual trip: In the formula, represents the start time of charging after vehicle k completes trip i, It indicates the start time when vehicle k performs the virtual end trip.

5. The method for combined charging and discharging scheduling of electric buses according to claim 4, characterized in that: Step 4 includes ensuring that each vehicle can complete the corresponding trip and each trip is executed within the specified time. The trip time constraint includes the following steps: Step 4.1.1: Vehicle operation meets the trip start time requirements: In the formula, represents the start time of vehicle k executing trip i, ST i , represents the start time of trip i; Step 4.1.2: Vehicle operation must meet the given travel time requirements: In the formula, CT i represents the duration of trip i; Step 4.1.3: Waiting time requirement before the vehicle makes the next trip: In the formula, represents the waiting time of vehicle k at the station after completing trip i, m i is the idle time from the starting point to the terminal of trip i, m j is the idle time from the starting point to the terminal of trip j; Step 4.1.4: The trip start / end / wait time is 0 when the vehicle is not running: Step 4.1.5: Decide on the time of the last virtual trip: In the formula, It indicates the start time when vehicle k performs the virtual end trip.

6. The method for combined charging and discharging dispatching of electric buses according to claim 4, characterized in that: Step 4 includes ensuring that the battery power of each vehicle is sufficient to complete the corresponding trip. The power constraint includes the following steps: Step 4.2.1: Set the vehicle battery to be fully charged at the start of each day: In the formula, represents the power of vehicle k at the beginning of trip i, E full Indicates the amount of power when the battery is fully charged; Step 4.2.2: Set the vehicle battery to be fully charged at the end of each day: In the formula, represents the battery capacity of vehicle k after completing trip i; Step 4.2.3: The battery is considered fully charged when it is charged to more than 90%: AND full =90%*And max # (42) In the formula, E max Indicates the maximum power allowed by the battery; Step 4.2.4: Battery capacity constraints: In the formula, E min Indicates the minimum safe power allowed by the battery; Step 4.2.5: The vehicle must have enough power to complete the journey: In the formula, E i represents the power consumption of trip i; Step 4.2.6: After completing trip i, the amount of power required to execute trip j is: In the formula, represents the power of vehicle k at the beginning of trip j, n i represents the power consumption of the empty driving distance from the starting point of trip i to the terminal, n j represents the power consumption of the empty driving distance from the starting point to the station of trip j, γ r is the charging power of charging pile r; Step 4.2.7: The amount of power charged after the last virtual trip:

7. The method for combined charging and discharging scheduling of electric buses according to claim 1, characterized in that: Step 4 includes obtaining the optimal driving route and charging and discharging strategy of the electric bus, and finding the corresponding charging and discharging power constraints within the time-of-use electricity price section, including the following steps: Step 4.3.1: Charging duration constraints within the time-of-use electricity price range: In the formula, represents the charging duration of vehicle k within the time period τ after completing trip i, Indicates whether vehicle k is charged within time period τ after completing trip i, Dur τ Indicates the duration of each time period; Step 4.3.2: Total charging time within the time-of-use electricity price range: In the formula, The duration of charging for vehicle k after completing trip i; Step 4.3.3: Charging auxiliary variable constraints: Step 4.3.4: Constraints related to auxiliary variable charging within the time-of-use electricity price range: In the formula, Indicates whether the start time of charging after vehicle k completes trip i is greater than the start time of time period τ, represents the start time of charging after vehicle k completes trip i, Indicates whether the start time of charging after vehicle k completes trip i is less than the end time of time period τ, Start τ Indicates the start time of each time period, Dur τ Indicates the duration of each time period. Indicates whether vehicle k is charged within time period τ after completing trip i; Step 4.3.5: Discharge duration constraints within the time-of-use electricity price range: In the formula, represents the discharge duration of vehicle k in time period τ after completing trip i, Dur represents the duration of each time period, Indicates whether vehicle k discharges within time period τ after completing trip i; Step 4.3.6: Total discharge duration within the time-of-use electricity price range: Step 4.3.7: Discharge auxiliary variable constraints: Step 4.3.8: Discharge-related constraints of auxiliary variables within the time-of-use electricity price range: In the formula, Indicates whether the start time of discharging after vehicle k completes trip i is greater than the start time of time period τ, Qik indicates the start time of discharging after vehicle k completes trip i, Indicates whether the start time of discharging after vehicle k completes trip i is less than the end time of time period τ, Start τ Indicates the start time of each time period, Dur τ Indicates the duration of each time period. Indicates whether vehicle k discharges within time period τ after completing trip i.

Images