JP7563205B2 - Commercial electric vehicle operation management system - Google Patents

Description

The present invention relates to a traffic management system that manages the operation of commercial electric vehicles.

Electric vehicles store electricity in an on-board battery and run by using this electricity to drive a motor. The characteristics of a battery change depending on its temperature. There is known technology that changes the charge/discharge control in response to changes in characteristics caused by changes in the battery's temperature. The following Patent Document 1 discloses technology for controlling the battery of a hybrid vehicle, in which the upper and lower limits of the input/output voltage to the battery are changed depending on the battery temperature.

JP 2006-81300 A

Batteries tend to take longer to charge when the temperature is low. Particularly in commercial vehicles such as route buses and taxis, long charging times result in reduced vehicle operating rates.

The purpose of this invention is to shorten the charging time at low temperatures.

The operation management system of the present invention is an operation management system that manages the operation of a commercial electric vehicle, and has a charge/discharge control unit that controls the charging/discharging of a battery mounted on the commercial electric vehicle, an outside air temperature acquisition unit that acquires the outside air temperature, and a charge time setting unit that sets the charging time per charge to a low temperature charging time that is shorter than the charging time when the outside air temperature is higher than the specified temperature when the acquired outside air temperature is lower than a specified temperature.

When a battery is charged when the amount of stored power is low, the battery generates more heat than when the amount of stored power is high, causing the battery temperature to rise. When the outside temperature is low and the battery temperature tends to drop, shortening the charging time per charge increases the number of times the battery is charged when the amount of stored power is low, and the battery temperature can be increased. When the battery temperature is high, charging efficiency is better than when it is low, and by shortening the charging time per charge, the total charging time can be shortened even if the number of charges in a certain period increases.

1 is a schematic diagram showing a schematic configuration of a traffic system according to an embodiment of the present invention; 1 is a schematic diagram showing a schematic configuration of a vehicle according to an embodiment of the present invention; FIG. 11 is a diagram showing the results of a simulation of changes in the amount of stored electricity and the battery temperature when charging is performed in a state where the amount of stored electricity is high. FIG. 11 is a diagram showing the results of a simulation of changes in the amount of stored electricity and the battery temperature when charging is performed in a state where the amount of stored electricity is low. 1 is a block diagram illustrating an example of a traffic control system according to an embodiment of the present invention; 5 is a chart showing an example of a control flow related to setting of a charging time according to the present embodiment. FIG. 2 is a block diagram showing functions of a traffic management device and a battery control device according to the embodiment. FIG. 11 is a diagram showing changes in the amount of stored electricity when the charging time is long and when it is short. FIG. 11 is a block diagram showing functions of a traffic management device and a battery control device according to another embodiment of the present invention. FIG. 11 is a diagram showing changes in the amount of stored electricity when the charging time is long and when it is short. FIG. 11 is a block diagram showing functions of a traffic control system according to still another embodiment of the present invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a schematic diagram of a route bus operation system 10. A route bus vehicle 12 runs along a determined route (route) 14 according to an operation plan, and stops 16 are provided at multiple locations along the route 14. The operation system 10 has two routes 14, namely, a circular route 14A and a round trip route 14B. The route may be either a circular route or a round trip route, or may have more routes. The vehicle 12 runs around the circular route 14A in one direction while stopping at each stop 16 or at a necessary stop 16, and also travels back and forth along the round trip route 14B. The vehicle 12 is an electric vehicle that runs on the power of an on-board battery. A charging station 18 is provided adjacent to the route 14, and the vehicle 12 charges its battery at the charging station 18. A charging stand 20 is provided at the charging station 18, and charging is performed by connecting a plug provided on the vehicle 12 to an outlet of the charging stand 20. The operation of the vehicles 12 is managed by an operation management center 22. The operation management center 22 assigns each vehicle 12 to each trip defined by the operation plan based on predetermined information such as the route of each route 14 and the operation plan, as well as the operation status of each vehicle 12, such as the battery charge and number of passengers, which change from time to time, and external conditions such as outside temperature and traffic congestion information. An operation management device 24 is installed in the operation management center 22, and the operation management device 24 manages all or part of the operation of each vehicle 12. Part of the operation management may be performed by an operator in the operation management center 22. The operation plan may include information about a trip defined as a trip from when one vehicle departs from the charging station 18 to when it returns to the charging station 18 (the mileage of the trip, the departure/arrival time of each stop, etc.), and the allocation of each vehicle 12 to each trip.

Figure 2 is a diagram showing the schematic configuration of the vehicle 12. As described above, the vehicle 12 is an electric vehicle driven by an electric motor 30. In the following, the electric motor 30 is simply referred to as the motor 30. The vehicle 12 is equipped with a battery 32 that stores the power supplied to the motor 30, and a battery control device 34 that controls the battery 32. The battery control device 34 controls the power supplied from the battery 32 to the motor 30 according to the requested power, and also controls the charging of the regenerative power of the motor 30 to the battery 32. During charging, the battery control device 34 also controls the charging of the battery 32 with power from an external source such as the charging station 20. The vehicle 12 is further equipped with an outside air temperature sensor 36 that measures the outside air temperature, and a battery temperature sensor 38 that measures the temperature of the battery 32.

Figures 3 and 4 show a comparison of the simulation results of the amount of stored electricity and the battery temperature when charging is performed when the amount of stored electricity is high and when charging is performed when the amount of stored electricity is low. Figure 3 shows the simulation results when the amount of stored electricity is high, specifically when the amount of stored electricity is managed in the range of 40-80%. The changes in the amount of stored electricity and the battery temperature are shown when the battery is charged to the upper limit of the management range, consumed to the lower limit, and then charged again to the upper limit amount. Figure 4 shows the simulation results when the amount of stored electricity is low, specifically when the amount of stored electricity is managed in the range of 25-65%. The outside air temperature is set to a minimum of -6°C and a maximum of 5°C, assuming winter, and the daily fluctuations are the same each day. After driving for 73.5 minutes, the vehicle 12 returns to the charging station 18 and charges. Charging is performed until the amount of stored electricity reaches the upper limit amount, and operation is resumed after charging is completed. This driving and charging are repeated without a break. In the simulation results of Figures 3 and 4, the battery temperature is low at the beginning of the simulation, so this time period will be excluded for comparison and analysis.

When the storage capacity management range was set to 40-80% (Figure 3), the charging time was 85-110 minutes, the average battery temperature was 8.4°C, and the average charging power was 10kW. In contrast, when the management range was set to 25-65% (Figure 4), the charging time was 70-85 minutes, the average battery temperature was 11°C, and the average charging power was 13kW. This shows that charging with a low storage capacity results in a higher battery temperature and a higher average charging power.

The operation system 10 has an operation management system 40 that manages the operation of each vehicle 12. Figure 5 is a functional block diagram showing the functions of the operation management system 40. The operation management system 40 has a charge/discharge control unit 42 that controls the charging and discharging of the battery 32. The charge/discharge control unit 42 controls the power supplied to the motor 30 and the power regenerated from the motor 30, and also controls charging the battery 32 from the outside. The charge/discharge control unit 42 also controls the amount of electricity stored in the battery 32 to be within a management range between a predetermined upper and lower limit storage amount, and also charges the vehicle 12 with the amount of electricity required to operate the next trip based on the operation plan.

The traffic management system 40 further includes an outside air temperature acquisition unit 44. The outside air temperature acquisition unit 44 acquires the outside air temperature around the vehicle 12 at that time based on a signal from an outside air temperature sensor 36 provided in the vehicle 12. The outside air temperature sensor may be installed at one or more locations near the route 14, or at the traffic management center 22. The outside air temperature acquisition unit 44 may receive weather information sent by a public institution such as the Japan Meteorological Agency or a private service institution, and acquire the temperature of the area including the route 14 as the outside air temperature. Information may be exchanged between the vehicle 12 and the traffic management center 22 via a wired or wireless connection. When acquiring information via a wired connection, for example, information is sent and received via a wired connection while charging at the charging station 18.

The operation management system 40 further includes a charging time setting unit 46. The charging time setting unit 46 sets the time required for one charging (hereinafter referred to as charging time). One charging time may be a predetermined time, or may be determined based on the amount of power required to operate the next service after charging. The charging time setting unit 46 may obtain the travel distance of the next service based on the operation plan, and set the charging time based on the time required to charge the amount of power according to the travel distance. The charge/discharge control unit 42 performs one charging based on the set charging time.

When the outside air temperature acquisition unit 44 provides information that the outside air temperature is lower than a predetermined temperature and is therefore low, the charging time setting unit 46 sets the charging time to a low-temperature charging time that is shorter than when the temperature is higher than the predetermined temperature (hereinafter referred to as normal temperature). The low-temperature charging time may be set to a time shorter than the time required to charge from the lower limit charge amount to the upper limit charge amount at normal temperature, for example. In addition, if the charging time per charge at normal temperature is set, the low-temperature charging time may be set to a time shorter than this normal temperature charging time.

The charging time setting unit 46 may set a charging time corresponding to the driving distance of the vehicle 12 that has been shortened by changing the operation plan at low temperatures. If the driving distance of the next trip is shorter than that at normal temperatures, the charging time can be shortened, and charging with a low amount of stored electricity is repeated.

By shortening the charging time per charge, the battery 32 is repeatedly used with a low amount of stored power. This increases the number of times the battery is charged with a low amount of stored power and generates a lot of heat, causing the battery temperature to rise.

Figure 6 is an example of a flowchart related to control for changing the charging time per charge depending on the outside air temperature. The outside air temperature T is acquired (S100), and it is determined whether the acquired outside air temperature T exceeds a predetermined temperature (e.g., 5°C) (S102). If it exceeds the predetermined temperature, the charging time is set to a long charging time set for normal temperatures (S104). On the other hand, if the outside air temperature T is equal to or lower than the predetermined temperature in step S102, the charging time is set to a short charging time set for low temperatures, i.e., a charging time shorter than the charging time at normal temperatures (S106).

Figure 7 is a functional block diagram showing a more specific example of a traffic management system. Traffic management system 50 is composed of traffic management device 24 and battery control device 34. Traffic management device 24 and battery control device 34 are configured so that a predetermined function is realized by the processing device executing a predetermined program.

The battery control device 34 has a charge/discharge control unit 52 that controls the charging and discharging of the battery 32. The charge/discharge control unit 52 controls the power supplied to the motor 30, the power regenerated from the motor 30, and also controls charging the battery 32 from the outside. The charge/discharge control unit 52 also controls the amount of charge stored in the battery 32 within a management range between a predetermined upper limit charge amount and a lower limit charge amount. The charge/discharge control unit 52 may be configured to end charging when a set charging time has elapsed. If the upper limit charge amount is reached before the charging time has elapsed, charging is ended at that point. When the amount of charge stored in the battery 32 reaches or approaches the lower limit charge amount during operation of the vehicle 12, this may be notified and charging may be encouraged. The amount of charge stored in the battery 32 is managed in an intermediate range so that the amount of charge is not 100% or 0%, taking durability into consideration, for example, in the range of 40-80%. As described below, in this vehicle 12 or battery control device 34, the charging time per charge is changed according to information related to the outside air temperature.

The battery control device 34 includes a mileage-based charging time setting unit 54 that sets a charging time corresponding to the mileage of the next trip of the vehicle 12 in which the battery control device 34 is installed. The mileage of the next trip is acquired by the next mileage acquisition unit 56 from the operation plan 64 stored in the operation management device 24 (the operation plan will be described later). The mileage for the next trip may be acquired by the vehicle 12 from the operation management center 22 via a wired or wireless connection. When the mileage for the next trip is acquired via a wired connection, for example, it may be acquired from the operation management center 22 while the vehicle 12 is parked at the charging station 18. Furthermore, the lower limit charge capacity may be changed according to information related to the outside air temperature. The battery control device 34 may include a lower limit charge capacity setting unit 58 that sets the lower limit charge capacity.

The battery control device 34 further includes a power storage amount monitoring unit 60. The power storage amount monitoring unit 60 monitors the amount of power storage controlled by the charge/discharge control unit 52, in particular the amount of power storage at the end of charging.

The operation management device 24 includes a memory unit 66 that stores basic information 62 about routes, such as the distance and travel time between each route 14 and each stop 16, as well as an operation plan 64 for each service. The operation plan 64 includes information about the route 14 of each service, the departure and arrival times at the charging station 18, and the departure time for each stop 16, and further includes individual information about the vehicles 12 assigned to each service. The operation management device 24 includes a vehicle allocation unit 68 that allocates vehicles 12 to each service. The vehicle allocation unit 68 allocates vehicles 12 to each service based on the basic information 62, the status of each vehicle 12, and external information.

The traffic management device 24 has an outside air temperature acquisition unit 70. The outside air temperature acquisition unit 70 acquires the outside air temperature around the vehicle 12 at that time based on a signal from an outside air temperature sensor 36 provided in the vehicle 12. The outside air temperature sensor may be installed at one or more locations near the route 14, or at the traffic management center 22. The outside air temperature acquisition unit 70 may receive weather information sent by a public institution such as the Japan Meteorological Agency or a private service institution, and acquire the temperature of the area including the route 14 as the outside air temperature. Information may be exchanged between the vehicle 12 and the traffic management center 22 via a wired or wireless connection. When acquiring information via a wired connection, for example, information is sent and received via a wired connection while charging at the charging station 18.

The traffic management device 24 further includes an outside temperature forecast acquisition unit 72. The outside temperature forecast acquisition unit 72 acquires weather forecasts issued by public organizations such as the Japan Meteorological Agency or private service organizations, and acquires the temperature within or after a specified time period, or the minimum temperature the following morning.

The operation management device 24 has an operation plan change unit 74. The operation plan change unit 74 may change the driving plan based on the outside air temperature acquired by the outside air temperature acquisition unit 70. The operation plan change unit 74 changes the operation plan so that the travel distance of each trip is shortened when the temperature is low. The operation plan change unit 74 may also change the operation plan based on information from the outside air temperature forecast acquisition unit 72. When a forecast of low temperatures is acquired in the future, the operation plan change unit 74 changes the operation plan so that the travel distance of each trip is shortened. Operation plans for normal temperature and low temperature may be stored in advance in the memory unit 66, and one of the operation plans may be selected based on the outside air temperature and the outside air temperature forecast.

In this operation management system 50, the operation plan change unit 74, the next mileage acquisition unit 56, and the mileage-based charging time setting unit 54 function as a charging time setting unit 46 that sets the charging time per charging to a low-temperature charging time that is shorter than the charging time at normal temperature when the temperature is low.

As an example of operation, the vehicle 12 will be described by taking an operation in which the vehicle 12 repeatedly travels around the circuit route 14A. At room temperature, the vehicle 12 charges up to 80%, which is the upper limit of the battery storage capacity, at the charging station 18, and then travels around the circuit route 14A twice, returns to the charging station 18, and repeats the operation of charging again. An operation plan of this pattern is stored in the memory unit 66 as an operation plan at room temperature. The time required to charge the amount of power consumed when traveling around the circuit route 14A twice is th1. This time th1 is referred to as the charging time at room temperature th1.

When the outside air temperature is low based on the outside air temperature acquired by the outside air temperature acquisition unit 70, or when the outside air temperature is predicted to be low based on the outside air temperature forecast acquired by the outside air temperature forecast acquisition unit 72, the operation plan change unit 74 changes the operation plan to shorten the travel distance of the bus. Specifically, the operation plan is changed to one in which the bus returns to the charging station 18 and charges after each revolution of the circuit route 14A. This pattern is stored in the memory unit 66 as the low temperature operation plan. The next travel distance acquisition unit 56 acquires the travel distance of the bus after charging of the vehicle 12 from the operation management device 24, and the travel distance corresponding charging time setting unit 54 sets the charging time tc1 corresponding to this travel distance. This time tc1 is referred to as the low temperature charging time tc1. In this example, the low temperature charging time tc1 is the time required to obtain the amount of charge required to make one revolution of the circuit route 14A.

Figure 8 shows the change in the amount of stored electricity when the circuit path 14A is repeatedly circulated as described above. The change at room temperature is shown by the thin line H1, the change when charging to the upper limit of stored electricity at low temperature is shown by the dashed line Cb1, and the change when the charging time is shortened at low temperature is shown by the thick line Ca1. The boundary between low temperature and room temperature can be set at 5°C, for example. The upper limit of stored electricity is, for example, 80%. Initially, at low temperature, the temperature of the battery 32 is low and charging efficiency is poor, but repeated charging with a low amount of stored electricity increases the temperature of the battery 32 and improves charging efficiency. As shown in the figure, at low temperature, charging is repeated with a lower amount of stored electricity than at room temperature, the amount of heat generated by the battery 32 increases, and the temperature of the battery 32 rises.

As described above, in an operation in which a fixed route is traveled multiple times, then the battery is charged, and the same route is traveled again, the frequency of charging when the amount of stored electricity is low can be increased by reducing the number of travels between charges at low temperatures compared to normal temperatures and reducing the charging time accordingly. When a single route is traveled repeatedly, a low-temperature charging time tc1 corresponding to the travel distance of this single route may be determined in advance, and charging may be performed at the determined low-temperature charging time tc1 at low temperatures. When there is a possibility of traveling multiple routes, the low-temperature charging time tc1 corresponding to the next travel may be obtained, and charging may be performed at the obtained low-temperature charging time tc1. A correspondence table showing the correspondence with the travel distance may be stored in advance, and the low-temperature charging time tc1 may be obtained based on this correspondence table. The low-temperature charging time tc1 may also be obtained by determining the relationship with the travel distance as a function in advance and calculating the low-temperature charging time tc1 using this function.

Since charging efficiency changes depending on the temperature of the battery 32, the low temperature charging time tc1 may be made adjustable. For example, when repeatedly traveling a fixed route, the amount of stored electricity at the end of charging is monitored by the stored electricity monitoring unit 60, and if this amount of stored electricity changes, the low temperature charging time tc1 may be adjusted to suppress this change. For example, if there is a tendency for the amount of stored electricity at the end of charging to increase, adjustments are made to shorten the low temperature charging time tc1.

The outside air temperature forecast acquisition unit 72 may acquire a forecast covering several days, such as a weekly weather forecast. If the forecast for this period predicts low temperatures, the operation plan change unit 74 sets the operation plan to an operation plan for low temperatures during this period. The low temperature during a period may be determined, for example, by the number of days during which the minimum temperature falls below a predetermined temperature reaching a predetermined number during the period. For example, if the minimum temperature falls below the predetermined temperature on three days out of seven days, the charging time and the minimum storage capacity may be set to the low temperature charging time and the low temperature minimum storage capacity during this period.

In addition, the lower limit storage amount may be lowered at low temperatures so that charging is performed with a lower storage amount. When the lower limit storage amount setting unit 58 receives information from the operation management device 24 that the outside air temperature is low or will become low, it sets the lower limit storage amount to a low temperature lower limit storage amount that is lower than normal temperature. The lower limit storage amount may be set to, for example, 25%. After the low temperature lower limit storage amount is set, the charging time during the first or initial charging may be shorter than the low temperature charging time tc1 so that the storage amount is further reduced during the next driving.

Figure 9 is a functional block diagram showing another specific example of a traffic management system. Traffic management system 80 is composed of traffic management device 82 and battery control device 84. Traffic management device 82 is provided in traffic management center 22 in place of traffic management device 24 described above. Battery control device 84 is mounted on vehicle 12 in place of battery control device 34 described above. Traffic management device 82 and battery control device 84 are configured to realize predetermined functions by the processing device executing a predetermined program.

In the traffic management system 80, the same components as those in the traffic management system 50 described above are given the same reference numerals, and the description thereof is omitted. The battery control device 84 of the traffic management system 80 includes a charging time setting unit 86 that sets the charging time th2 per charge at room temperature (charging time th2 at room temperature) and the charging time tc2 per charge at low temperature (charging time tc2 at low temperature). The charging time tc2 at low temperature is shorter than the charging time th2 at room temperature. The charging time setting unit 86 sets the charging time to either the charging time th2 at room temperature or the charging time tc2 at low temperature based on the outside air temperature acquired by the outside air temperature acquisition unit 70. The charging time setting unit 86 also sets the charging time to either the charging time th2 at room temperature or the charging time tc2 at low temperature based on the outside air temperature forecast acquired by the outside air temperature forecast acquisition unit 72. The outside air temperature acquisition unit 70 and the outside air temperature forecast acquisition unit 72 may be provided in the battery control device 84, or may be provided in the traffic management device 82 as in the traffic management system 50 described above.

At room temperature, the charging time setting unit 86 sets the charging time to the room temperature charging time th2, and the charge/discharge control unit 52 accordingly controls charging with one charging time set to the room temperature charging time th2. When the outside air temperature becomes low, or is expected to become low, the charging time setting unit 86 sets the charging time to the low temperature charging time tc2, and the charge/discharge control unit 52 accordingly controls charging with one charging time set to the low temperature charging time tc2. At low temperatures, the charging time becomes shorter, the amount of heat generated by the battery 32 becomes large, and there are more opportunities to charge when the amount of stored power is low, causing the temperature of the battery 32 to rise.

The amount of stored power at the start of the next charge varies depending on the distance traveled after charging, so if the charging time is fixed, the amount of stored power at the end of the charging time will vary. If the amount of stored power increases due to this variation, charging will not be possible when the amount of stored power is low. To prevent this, the stored power monitoring unit 60 monitors the amount of stored power at the end of charging, and when the amount of stored power at the end of charging is on the rise or has reached a predetermined value, the charging time setting unit 86 adjusts the low temperature charging time tc2 to be shorter.

The operation management device 82 adopts an operation plan according to the normal temperature charging time th2 and the low temperature charging time tc2, and dispatches vehicles accordingly. Because the low temperature charging time tc2 is shorter than the normal temperature charging time th2, the subsequent travel distance will be shorter than at normal temperature. The memory unit 66 stores operation plans for normal temperature and low temperature that take this travel distance into account. The operation plan change unit 88 changes the operation plan according to the charging time set by the charging time setting unit 86, and the dispatch unit 68 dispatches vehicles accordingly.

Figure 10 shows the change in the amount of stored electricity when the battery is charged for a specified time from the lower limit of the amount of stored electricity, then driven, and when the amount of stored electricity falls to the lower limit of the amount of stored electricity, charging is resumed for the specified time again. The thin line H2 shows the change in the amount of stored electricity when the outside temperature is at room temperature, and the thick line Ca2 shows the change in the amount of stored electricity when the outside temperature is at a low temperature. The boundary between low temperature and room temperature can be set at 5°C, for example. The lower limit of the amount of stored electricity is, for example, 40%.

The charging time setting unit 86 sets the charging time at room temperature to th2, and the charge/discharge control unit 52 ends charging when the charging time from the start of charging reaches the room temperature charging time th2. At room temperature, as shown by the thin line H2 in FIG. 10, charging is performed from the lower limit charge state for the room temperature charging time th2, and then the vehicle is driven. When the charge level falls to the lower limit charge level, charging is performed again for the room temperature charging time th2.

When the outside air temperature drops and the temperature of the battery 32 also drops, the charging efficiency decreases, and the charge amount at the end of charging decreases even if charging is performed for the normal temperature charging time th2. The change in the charge amount at this time is shown by the dashed line Cb2. When the outside air temperature is low based on the outside air temperature acquired by the outside air temperature acquisition unit 70, or when the outside air temperature is predicted to be low based on the outside air temperature forecast acquired by the outside air temperature forecast acquisition unit 72, the charging time setting unit 86 sets the charging time to a low temperature charging time tc2 that is shorter than the normal temperature charging time th2. At low temperatures, as shown by the thick line Ca2 in FIG. 10, charging is performed for the low temperature charging time tc2 from the lower limit charge amount, and then the vehicle is driven, and when the charge amount drops to the lower limit charge amount, charging is performed again for the low temperature charging time tc2. By shortening the charging time, the number of opportunities to charge in a state where the amount of charge is low and the amount of heat generated increases, and the temperature of the battery 32 rises. By charging in a high temperature state, the charging efficiency improves and the total charging time in a certain period can be shortened.

The outside air temperature forecast acquisition unit 72 may acquire a forecast covering several days, such as a weekly weather forecast. If the forecast for this period predicts low temperatures, the operation plan change unit 88 sets the operation plan to a low temperature operation plan for this period. The low temperature during the period may be determined, for example, by the number of days during which the minimum temperature falls below a predetermined temperature reaching a predetermined number during the period. For example, if the minimum temperature falls below the predetermined temperature on three days out of seven days, the charging time and the minimum storage capacity may be set to the low temperature charging time and the low temperature minimum storage capacity during this period.

In addition, the lower limit storage amount may be lowered at low temperatures so that charging is performed with a lower storage amount. When the lower limit storage amount setting unit 58 receives information from the outside air temperature acquisition unit 70 or the outside air temperature forecast acquisition unit 72 that the outside air temperature is low or will become low, it sets the lower limit storage amount to a low temperature lower limit storage amount that is lower than normal temperature. The lower limit storage amount may be, for example, 25%. After the low temperature lower limit storage amount is set, the charging time during the first or initial charging may be shorter than the low temperature charging time tc2 so that the storage amount is further reduced during the next driving.

The battery control device 84 monitors the amount of stored power at the end of charging, and if the amount of stored power is on the rise, the low temperature charging time tc2 may be set even shorter. The stored power monitoring unit 60 monitors the amount of stored power at the end of charging at low temperatures. The amount of stored power at the end of charging can be obtained from the charge/discharge control unit 52. If the amount of stored power at the end of charging has increased by a predetermined amount compared to the amount at the end of the previous charging for a predetermined number of consecutive times, the stored power monitoring unit 60 determines that the amount of stored power is on the rise. An increase in the amount of stored power indicates that the power stored in one charging session was not consumed by subsequent driving and remains. In other words, it is understood that shorter distances are being driven repeatedly, and there is room to shorten the charging time. When the stored power monitoring unit 60 determines that the amount of stored power is on the rise, the charging time setting unit 86 further shortens the low temperature charging time tc2. This increases the number of charging opportunities when the amount of stored power is low, and the temperature of the battery 32 rises.

Some of the functions of the battery control device 84 and the operation management device 82 described above may be executed by an operator on board the vehicle 12 or an operator at the operation management center 22. For example, the vehicle 12 may be provided with a monitor that displays the outside temperature, and the operator may manually change the charging time when the outside temperature displayed on the monitor becomes low. Also, the operator at the operation management center 22 may change the charging time remotely.

Figure 11 is a diagram showing yet another embodiment, and is a block diagram showing the functions of the operation management system 90. The overall configuration of the operation system 10 and the configuration of the vehicle 12 can be the same as the embodiment shown in Figures 1 and 2. The operation management system 90 has a charge/discharge control unit 42 that controls the charging and discharging of the battery 32. The charge/discharge control unit 42 has already been described, so a description thereof will be omitted.

The operation management system 90 sets the charging time for one time in winter according to the season, particularly, shorter than the charging time in other seasons, and increases the number of charging opportunities when the amount of stored power is low, thereby maintaining a high battery temperature. When the battery temperature is high, charging efficiency is good, and increases in charging time due to low temperatures can be suppressed. The charging time setting unit 92 selectively sets a winter charging time to be used in winter and a summer charging time to be used in seasons other than winter. The winter charging time is shorter than the summer charging time. The charge/discharge control unit 42 controls charging of the battery 32 in winter, with the charging time set as the winter charging time. Outside winter, the charging of the battery 32 is controlled with the charging time set as the summer charging time. The charging time is set based on the season setting command 94.

An annual schedule in which the winter period is specified is stored, and when the start date of winter arrives, a time setting command 94 is issued to set the winter charging time, the winter lower limit storage amount, and the winter upper limit storage amount, and when the end date of winter passes, a time setting command 94 is issued to set the summer charging time, the summer lower limit storage amount, and the summer upper limit storage amount. Winter can be set, for example, from December 1st to the end of February, in which case the winter charging time, the winter lower limit storage amount, and the winter upper limit storage amount are set on December 1st, and the summer charging time, the summer lower limit storage amount, and the summer upper limit storage amount are set on March 1st. The annual schedule may be stored in a memory unit provided in the operation management system 90, and the time setting command 94 may be issued to each vehicle 12 based on the annual schedule. The annual schedule may also be stored in the vehicle 12. Alternatively, the season setting operation may be performed manually by an operator at the operation management center 22, an operator on board the vehicle 12, or a maintenance worker for the vehicle 12. Based on this operation, a command is issued and the winter charging time and summer charging time are set.

In the operation management system 90, a winter lower limit storage amount to be used in winter and a summer lower limit storage amount to be used in seasons other than winter may be selectively set. The winter lower limit storage amount is a value lower than the summer lower limit storage amount, and for example, the summer lower limit storage amount may be set to 40% and the winter lower limit storage amount to 25%. In addition, if the storage amount at the end of charging is on the rise, the winter charging time may be shortened.

In the operation system 10, only one charging station 18 is provided, but multiple charging stations may be provided. For example, a further charging station may be provided at the end point of the round-trip route 14B.

In addition, for vehicles that are not in operation for long periods of time, for example vehicles that do not operate from late at night to early in the morning when the number of users decreases, the charging time may not be limited and the vehicle may be fully charged (100%) even in low temperatures.

In the above embodiment, a route bus with a fixed route was described, but for taxis and hire cars with no fixed route, the charging time can be set to be short according to the present invention, so that charging is performed when the amount of stored electricity is low, thereby shortening the total charging time.

Other aspects of the present invention are described below.
(1)
This battery control method controls charging and discharging of a power battery of a commercial electric vehicle, and when the outside air temperature is lower than a predetermined temperature, the charging time for one charging cycle is set as a low-temperature charging time that is shorter than the charging time when the outside air temperature is higher than the predetermined temperature.
(2)
A traffic management system that manages the operation of a commercial electric vehicle,
A charge/discharge control unit that controls charging/discharging of a battery mounted on the commercial electric vehicle;
An outside temperature acquisition unit that acquires an outside temperature;
a mileage setting unit that sets, when the acquired outside air temperature is lower than a predetermined temperature, a mileage of one trip of the commercial electric vehicle to a low-temperature mileage that is shorter than a mileage when the outside air temperature is higher than the predetermined temperature;
a charging time setting unit that sets a low-temperature charging time required to charge an amount of electric power capable of traveling the low-temperature traveling distance when the low-temperature traveling distance is set;
An operation management system having the above.
(3)
An operation management method for managing the operation of a commercial electric vehicle that repeats a predetermined number of runs along a fixed route and charging, wherein, when an outside air temperature is lower than a predetermined temperature, the number of runs of the commercial electric vehicle along the fixed route is reduced compared to the number of runs when the outside air temperature is higher than the predetermined temperature, and when charging when the outside air temperature is lower than the predetermined temperature, charging is performed for a charging time corresponding to the next number of runs.
(4)
An operation management method for managing the operation of a commercial electric vehicle, the operation management method comprising: making a traveling distance of one trip of the commercial electric vehicle during a specified period in winter shorter than a traveling distance of one trip during a period other than the specified period in winter; and setting a single charging time to a charging time corresponding to the shortened traveling distance.

10 Operation system, 12 Vehicle, 14 Route, 18 Charging station, 22 Operation management center, 24, 82 Operation management device, 32 Battery, 34, 88 Battery control device, 36 Outside air temperature sensor, 40, 50, 80, 90 Operation management system, 42, 52 Charging and discharging control unit, 44, 70 Outside air temperature acquisition unit, 46, 86, 92 Charging time setting unit, 54 Travel distance-based charging time setting unit, 56 Next travel distance acquisition unit, 58 Lower limit storage amount setting unit, 60 Storage amount monitoring unit, 62 Basic information, 64 Operation plan, 66 Memory unit, 68 Vehicle dispatch unit, 72 Outside air temperature forecast acquisition unit, 74, 88 Operation plan change unit, th Charging time at normal temperature, tc Charging time at low temperature.

Claims (1)

A traffic management system that manages the operation of a commercial electric vehicle,
A charge/discharge control unit that controls charging/discharging of a battery mounted on the commercial electric vehicle;
An outside temperature acquisition unit that acquires an outside temperature;
a charging time setting unit that sets, when the acquired outside air temperature is lower than a predetermined air temperature, a charging time per charging to a low temperature charging time that is shorter than a charging time when the outside air temperature is higher than the predetermined air temperature;
An operation management system having the above.

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