JP5049218B2 - Electric vehicle system - Google Patents

Description

  The present invention relates to an electric vehicle system for optimally controlling a battery based on temperature information of an electric vehicle or a hybrid vehicle that runs using the battery as a power source.

Electric vehicles, hybrid vehicles, and the like are equipped with a battery as a secondary battery that can be charged and discharged at a high voltage of several hundred volts. Generally, a battery has a characteristic that when it is used in a high charge state or a high voltage state, and conversely, when used in a low charge state or a low voltage state, deterioration proceeds at an early stage. Accordingly, an upper limit value and a lower limit value of SOC (State Of Charge) that can be used are set according to the characteristics of each battery, and an optimal charging state is maintained. (For example, refer to Patent Document 1).
JP 2007-31309 A

  However, in such a conventional technique, since an upper limit value and a lower limit value are provided in order to maintain an optimal charging state, the usable battery capacity is reduced. In other words, it is necessary to mount an extra battery in order to achieve the required battery capacity. As a result, the battery mounted on the electric vehicle becomes large, which becomes a factor that hinders the reduction in size and weight of the vehicle. In addition, since the range of usable SOC is limited, when a battery is mounted on a hybrid vehicle or the like, the amount of battery energy that can be used to improve fuel efficiency is reduced, resulting in a decrease in vehicle efficiency. Resulting in. Furthermore, when a battery is mounted on an electric vehicle or the like, the range of SOC that can be charged is narrowed, resulting in a shorter cruising distance of the vehicle.

  The present invention has been made in view of such circumstances, and ensures the optimum usable range of SOC (and voltage) according to the temperature of the power storage device (battery), etc., and reduces the capacity of the mounted battery. An object of the present invention is to provide an electric vehicle system that can be used effectively.

In order to solve the above-described problem, the electric vehicle system according to the first or tenth aspect of the invention expands the usable range of the power storage device as the temperature of the power storage device or the temperature of the outside air decreases .
Furthermore, the electric vehicle system is connected in parallel to the power storage device, the reaction gas to generate electricity by supplying the fuel cell is mounted to supply electric power to the driving motor, if fuel cells are cold start Is provided with warming-up means for warming up by increasing the amount of power generation by supplying an excessive amount of reactive gas compared to the case where the cold start is not performed.
Then, an electric vehicle system, before Symbol power storage device with a larger usable range by the use range enlarging means stores electric least part of the generated power at the time of execution of said warming-up means.
In addition, when the ignition of the electric vehicle is turned off , the electric vehicle system acquires the predicted temperature information that is information on the predicted future temperature at the point, and the next driving start is based on the acquired predicted temperature information. If the target power storage amount of the power storage device is set, and the power storage amount of the power storage device at the time of ignition OFF does not reach the target power storage amount, the fuel cell is operated to store power until the power storage amount reaches the target power storage amount The power is stored in the device, and when the amount of power stored in the power storage device exceeds the usable range determined based on the current temperature information, the power stored in the power storage device is discharged.
Alternatively, when the ignition of the electric vehicle is turned off, the electric vehicle system acquires predicted temperature information that is information on the predicted temperature in the future at the point, and starts the next operation based on the acquired predicted temperature information. If the voltage value between the terminals of the power storage device at the time of ignition OFF does not reach the target voltage value, the fuel cell is operated and the voltage value between the terminals becomes the target voltage value. The power storage device is charged until it reaches the value, and when the voltage value between the terminals of the power storage device exceeds the usable range determined based on the current temperature information, the stored power of the power storage device is discharged. It is configured.

According to such a configuration, even when the battery (power storage device) is in a high SOC (amount of power storage) or a high voltage state, the power storage device can be suppressed at a low temperature by utilizing the fact that deterioration of the power storage device can be suppressed in a low temperature environment. By expanding the use area (usable range), the capacity of the power storage device can be effectively used. Normally, power storage devices are used within a range of SOC of about 40 to 60% for reasons such as deterioration limits, but by introducing optimal control of power storage devices according to the present invention, the usable range of SOC is expanded. Therefore, the power storage device can be reduced in size, and the energy of the regenerative power of the travel motor can be effectively recovered.
In the electric vehicle system, the temperature of the power storage device tends to increase as the outside air temperature increases. Further, if the temperature of the outside air is low, the temperature of the power storage device tends to be low.

Moreover, in the electric vehicle system of the invention according to claim 1 or claim 10 , the electric power generated at the time of warming-up is not consumed by a resistance load in the electric vehicle system, and the electric power can be effectively used. . Further, since the capacity of the receiving destination of the power generated at the time of warming-up is increased, Ru can do warm-up operation for a long period of time. Further, Ru can increase the power generation amount by excessively supplied reaction gas during cold start.
Furthermore, since the target power storage amount or target voltage value in the power storage device is set according to the predicted future temperature at the point where the ignition is turned off, the power storage device can be prevented from deteriorating, and the startability at the start of the next operation can be prevented. Can be improved.

In the electric vehicle system according to the third aspect of the present invention, the usable range expanding means is configured to calculate the use range of the storage amount as a percentage with the range in which the usable range is expanded as 100 percent. .

  According to such a configuration, by calculating the SOC usable range in percentage, the remaining capacity calculation corresponding to the expanded SOC range can be performed in percentage display, and the control of the power storage device of the vehicle is more efficient. Can be performed automatically.

The electric vehicle system of the invention according to claim 2 is a hybrid vehicle in which a fuel cell, which is a power generation device that supplies electric power to a traveling motor , is connected in parallel to a power storage device.

According to such a configuration, along with the expansion of the usable range of the amount of power stored in the power storage device,
The power storage device (fuel cell) can cope with an excessive power demand of the vehicle, and power generation in a region where the efficiency of the power generation device deteriorates can be prevented, so that improvement in vehicle fuel consumption can be expected.

Moreover, in the electric vehicle system of the invention which concerns on Claim 4, it is comprised so that a travel motor may serve as a charging device.
In the electric vehicle system according to the fifth aspect of the present invention, the predicted future temperature is the predicted temperature at the start of the next operation, and the target storage amount of the power storage device at the start of the next operation is The predicted temperature is set to be higher as the predicted temperature is lower, and set to be lower as the predicted temperature is higher.
Further, in the electric vehicle system of the invention according to claim 6, when the predicted temperature information at the point is lower than the predetermined temperature in the acquired predicted temperature information, the lower limit value of the storage amount at the end of the operation of the electric vehicle It is comprised so that it may become higher than the case where it is not lower than this temperature.
Furthermore, the electric vehicle system of the invention according to claim 7 further includes communication means, and is configured to acquire current temperature information and predicted temperature information based on position information and date / time information acquired by the communication means. Yes. The electric vehicle system according to claim 8 is configured such that the communication means is car navigation, and the electric vehicle system according to claim 9 is configured such that the communication means is a mobile phone.

In the electric vehicle system according to the fourth aspect, the regenerative power of the travel motor can be stored in the power storage device.
In the electric vehicle system according to the fifth aspect, deterioration of the power storage device can be prevented by appropriately controlling the amount of power stored in the power storage device.
Furthermore, in the electric vehicle system according to the sixth aspect, the start-up reliability can be ensured by increasing the output voltage at the start of the next operation.
In the electric vehicle system according to claims 7 to 9, more accurate predicted temperature information can be acquired.

  ADVANTAGE OF THE INVENTION According to this invention, the electric vehicle system which can utilize effectively the capacity | capacitance of the mounted electrical storage apparatus can be provided.

  The electric vehicle of the present embodiment acquires the temperature of the battery by a sensor installed in the battery (power storage device), or by communication means such as a car navigation system such as GPS (Global Positioning System) or a mobile phone. By acquiring information on the temperature of the outside air at the current position (hereinafter referred to as “air temperature”), or acquiring information on the current position, current date and time information, etc., and using that information for battery control, the SOC (amount of stored electricity) The battery can be used with high efficiency and long life by extending the usable range. That is, the present embodiment provides an electric vehicle that realizes a battery optimum control system that optimally controls the SOC of a battery based on temperature. Hereinafter, several embodiments will be described in detail with respect to the technical method of the battery optimum control system in the electric vehicle of the present embodiment, taking the electric vehicle as an example. In the drawings, the same components are denoted by the same reference numerals, and redundant description is omitted as much as possible.

<< First Embodiment >>
A first embodiment which is a reference embodiment will be described.
FIG. 1 is a configuration diagram of an electric vehicle system according to a first embodiment which is a reference embodiment . The electric vehicle system 10a includes a battery (power storage device) 1 serving as a power source for driving an electric vehicle, an inverter 2 that converts a DC voltage of the battery 1 into a three-phase AC voltage, and a three-phase AC voltage output from the inverter 2. A traveling motor 3 that rotates and drives the electric vehicle, and an ECU (Electronic Control Unit: usable range determination means, power storage device temperature acquisition means, and usable range expansion means) 4 that controls the entire electric vehicle system 10a; It is configured with. The battery 1 generates a high voltage of, for example, 250 V by an assembled battery in which unit cells such as a lithium-ion battery are combined.
In the first embodiment, which is a reference embodiment , the battery 1 is housed in a battery box (not shown), and the temperature of the battery 1 is measured by the power storage device temperature acquisition means by the temperature of the atmosphere in the battery box. Alternatively, it is obtained by directly measuring the temperature of the battery 1 or the like. Incidentally, the battery box is generally ventilated. Further, the temperature of the battery box (the temperature of the battery 1) tends to increase as the temperature increases and decrease as the temperature decreases.

  During downhill or deceleration of the electric vehicle, the travel motor 3 is rotated via a transmission (not shown), and regenerative electric power is generated in the travel motor 3. This regenerative power is configured to be converted into a DC voltage by the reverse conversion action of the inverter 2 and charged in the battery 1. That is, the travel motor 3 can also serve as a charging device by supplying regenerative power to the battery 1.

  The ECU 4 detects the current I from the current sensor 12 installed in the battery 1, the voltage V from the voltage sensor 11, and the temperature T from the temperature sensor 13 (power storage device temperature acquisition means) to detect the upper limit value and lower limit of the SOC in the battery 1. The value is calculated, and the battery control is performed so that the target voltage is output from the inverter 2 with the range of the upper limit value and the lower limit value of the SOC as the usable range of the SOC. That is, the ECU 4 directly detects the temperature T of the battery 1, determines the upper limit value and the lower limit value of the usable SOC corresponding to the current I and the voltage V of the battery 1, and the battery within the usable range of the SOC. Take control. Note that the ECU 4 can determine the upper limit voltage and the lower limit voltage of the battery 1 instead of the upper limit value and the lower limit value of the SOC and perform battery control within the voltage range.

  Next, a flow of processing for performing battery control based on temperature information in the battery 1 acquired by the temperature sensor 13 illustrated in FIG. 1 will be described. FIG. 2 is a flowchart showing a flow of processing for performing battery control based on temperature information acquired by the temperature sensor in the first embodiment of the present invention.

  In FIG. 2, the ECU 4 determines whether or not the ignition of the electric vehicle is turned on (step S1). If the ignition is not turned on (No in step S1), the ECU 4 waits until it is turned on. On the other hand, when the ignition is turned on (Yes in step S1), the ECU 4 acquires temperature information of the battery 1 by the temperature sensor 13 (step S2).

Next, the ECU 4 determines the upper limit value and the lower limit value of the SOC that can be used in the battery 1 based on the acquired temperature information, and sets the usable range of the SOC (step S3). Then, the ECU 4 controls the battery 1 within the usable SOC range, and drives and controls the travel motor 3 via the inverter 2 to drive the electric vehicle (step S4).
By the way, when the SOC usable range is expanded, the charging by regenerative power generation can be performed a lot, so the fuel efficiency is improved.

  Next, the ECU 4 determines whether or not the ignition of the electric vehicle is turned off (step S5). If the ignition is not turned off (No in step S5), the ECU 4 returns to step S2 and repeats the above processing. On the other hand, if the ignition is off (Yes in step S5), the ECU 4 predicts the predicted temperature information of the point (the predicted temperature at the future time) based on the position information and date / time information acquired by the communication means (car navigation) 5. ) Is acquired by the method described later, and the charging target SOC of the battery 1 is set to start the next operation based on the predicted temperature information (step S6). Here, the temperature is predicted to prevent the temperature sensor 13 from detecting the temperature of the battery 1 when the ignition is OFF, or to stop the temperature detection by the temperature sensor 13 and prevent the 12V battery from being consumed after the ignition is turned OFF. . If the SOC of the battery 1 does not reach the charging target SOC set in step S6, the ECU 4 turns the battery generator until the charging target SOC is reached by turning the generator with the engine provided in the electric vehicle (hybrid vehicle). 1 is charged. Incidentally, charging can also be performed by obtaining power from a commercial power source (outlet) of an electric power company. Step S6 may not be executed.

  Here, there are (1) a method using past weather information and (2) a method using weather forecast information for acquiring temperature information without using a temperature sensor.

(1) Using past weather information As a premise, the following three functions are provided on the vehicle side.
1. 1. Navigation function that can acquire the current position information (latitude / longitude) 2. Calendar function that can acquire current date and time information A database function in which temperature information (such as average temperature in the past n years) at the date and time of the position in the past is registered in association with the position information and the date and time information

  When the user wants to know the temperature, the navigation function obtains the current position information and obtains the current date / time information by the calendar function. And ECU4 searches a database with the acquired positional information and date information, and acquires temperature information (expected temperature information). When there is no temperature information corresponding to the corresponding position in the database, the ECU 4 acquires the temperature information of the closest position from the database, and uses the acquired temperature as predicted temperature information at the corresponding position and date. The same applies to the date and time, and when there is no information on the temperature of the corresponding date and time, the ECU 4 obtains the temperature information of the closest date and time (information considering the time) from the database, and the temperature information is the predicted temperature information. To do.

(2) When weather forecast information is used As a premise, the following two functions are provided on the vehicle side.
1. 1. Navigation function that can acquire the current position (latitude / longitude) 2. Calendar function that can acquire current date and time information A function that acquires weather forecast information using a communication function from a system (meteorological system) (not shown) that provides weather forecast information (including current weather information) at that position based on the location.

  When it is desired to know the temperature, first, the navigation function acquires the current position information of itself, and the current date and time information by the calendar function. Then, the communication means 5 such as car navigation transmits the acquired position information and date / time information to the weather system. The weather system transmits weather forecast information (including temperature information) at the corresponding position to the communication means 5 based on the transmitted position information and date / time information. When there is no weather forecast information corresponding to the corresponding position, the weather system transmits the weather forecast information of the nearest position and the nearest date and time to the communication means. The ECU 4 acquires temperature information included in the weather forecast information transmitted to the communication means 5 as predicted temperature information.

  FIG. 3 is a characteristic diagram showing the relationship between the battery temperature (battery temperature) and the upper limit value of the deterioration limit SOC, where the horizontal axis represents the battery temperature and the vertical axis represents the upper limit value of the deterioration limit SOC. Here, the deterioration limit SOC is an SOC in which the deterioration of the battery progresses when the value exceeds this value. This figure shows the characteristic that the upper limit value of the usable SOC (the upper limit value of the deterioration limit SOC) changes according to the battery temperature. That is, as can be seen from this characteristic diagram, the upper limit value of usable SOC decreases as the temperature of the battery increases, and the upper limit value of usable SOC increases as the temperature of the battery decreases. .

  FIG. 4 is a characteristic diagram showing the relationship between the battery temperature (battery temperature) and the lower limit value of the deterioration limit SOC, where the horizontal axis represents the battery temperature and the vertical axis represents the lower limit value of the deterioration limit SOC. This figure shows the characteristic that the lower limit value of the usable SOC (lower limit value of the deterioration limit SOC) changes according to the battery temperature. That is, as can be seen from this characteristic diagram, the lower limit value where the SOC can be used increases as the battery temperature increases, and the lower limit value where the SOC can be used decreases as the battery temperature decreases. .

  That is, the ECU 4 shown in FIG. 1 directly detects the temperature T of the battery 1, and based on the characteristic diagrams of FIGS. 3 and 4, the upper limit value and lower limit of the usable SOC according to the temperature T detected from the battery 1. The value is determined. The ECU 4 performs battery control while detecting the voltage V and current I of the battery 1 within the usable SOC range, and gives a control command signal to the inverter 2. Thereby, the inverter 2 outputs the target voltage corresponding to the control command signal to rotate the travel motor 3 within the usable range of the upper limit value and the lower limit value of the SOC in the battery 1. Then, the traveling motor 3 causes the electric vehicle to travel at a desired speed.

(Effects of the first embodiment)
According to the first embodiment, which is a reference embodiment, the capacity of the battery 1 can be effectively used by expanding the use area of the battery 1 in a low-temperature environment where deterioration of the battery 1 is suppressed. Along with this, it is possible to increase the size of the battery 1 and the recovery of the regenerative power of the travel motor 3.

<< Second Embodiment >>
A second embodiment which is a reference embodiment will be described.
In the configuration of the electric vehicle system of the first embodiment (reference embodiment) shown in FIG. 1, the ECU 4 (FIG. 1) directly detects the temperature T of the battery 1 (or the ambient temperature in the battery box), and the temperature T Battery control is performed based on the upper limit value and the lower limit value of the SOC corresponding to the electric vehicle system 10b of the second embodiment (reference embodiment) described in detail later with reference to FIG. The ECU 4a as the apparatus temperature acquisition means includes communication means such as car navigation having a communication function. Thereby, ECU4a acquires the predicted temperature information which is the information regarding temperature based on the positional information and date information which the communication means acquired, and based on the upper limit value and lower limit value of SOC calculated | required by this predicted temperature information To control the battery.
The second embodiment, which is the reference embodiment, is an embodiment that performs control using the above-described tendency that the temperature of the battery 1 increases as the temperature increases, and conversely decreases as the temperature decreases. . In addition, this second embodiment is an embodiment in which information on the temperature is not measured by a temperature sensor mounted on the vehicle but is acquired from the outside and used for control.

  FIG. 5 is a configuration diagram of an electric vehicle system according to the second embodiment of the present invention. The configuration of the electric vehicle system 10b shown in FIG. 5 is different from the electric vehicle system 10a of FIG. 1 in that communication means 5 such as car navigation is connected to the ECU 4a.

  That is, the car navigation system (communication means 5) of the electric vehicle system 10b has a function of receiving a radio wave from a GPS satellite (not shown) and determining its own position (latitude, longitude, and altitude) on the earth. It has a function to acquire date and time information. And ECU4a acquires the predicted temperature information which is the information of the position and the temperature of the date and time based on the position information calculated by the communication means (car navigation) 5 and the date and time information, and based on the predicted temperature information, The upper limit value and the lower limit value of the usable SOC are determined. Further, the ECU 4a performs battery control while detecting the voltage V and current I of the battery 1 within the usable range of the SOC. Note that the ECU 4a can determine the upper limit voltage and the lower limit voltage of the battery 1 instead of the upper limit value and the lower limit value of the SOC and perform battery control within the voltage range.

  Next, the flow of processing for performing battery control based on the predicted temperature information will be described. FIG. 6 is a flowchart showing a flow of processing for performing battery control based on predicted temperature information in the second embodiment of the present invention.

  In FIG. 6, the ECU 4a determines whether or not the ignition of the electric vehicle is turned on (step S11). If the ignition is not turned on (No in step S11), the ECU 4a waits until it is turned on. On the other hand, when the ignition is turned on (Yes in step S11), the communication means (car navigation) 5 acquires position information, date / time information, and the like based on the control of the ECU 4a (step S12). Then, the ECU 4a acquires the predicted temperature information based on the position information, date information, etc. (step S13). The acquisition method is one of the methods (1) and (2) described above in the first embodiment.

  Next, the ECU 4a determines an upper limit value and a lower limit value of the SOC that can be used in the battery 1 based on the acquired predicted temperature information, and sets the usable range of the SOC (step S14). Since the method for obtaining the upper limit value and the lower limit value of the SOC in this case is the same as the method performed using the characteristic diagrams of FIGS. 3 and 4 as described in the first embodiment, the overlapping description will be omitted. Omitted. That is, the upper limit value and the lower limit value of the SOC in the second embodiment are calculated using the diagrams in which the horizontal axis in FIGS. 3 and 4 is the predicted temperature. Then, the ECU 4a controls the battery 1 within the usable SOC range, and drives and controls the travel motor 3 via the inverter 2 to drive the electric vehicle (step S15).

Next, the ECU 4a determines whether or not the ignition of the electric vehicle is turned off (step S16). If the ignition is not turned off (No in step S16), the ECU 4a returns to step S12 and repeats the processing described above. On the other hand, if the ignition is turned off (Yes in step S16), the ECU 4a uses the position information and date / time information acquired by the communication means (car navigation) 5 to predict the predicted temperature information at the future time of the point (from the current time ahead). (Estimated temperature information) of the battery 1 is acquired, and based on the predicted temperature information, the charging target SOC of the battery 1 is set to start the next operation (step S17). The method for acquiring the predicted temperature information at the future time is the same method as any one of (1) and (2) described above in the first embodiment, and the predicted date is estimated at that position with reference to the position and date. The information on the maximum temperature to be obtained is acquired, and the information on the maximum temperature is used as the predicted temperature information. If the SOC of the battery 1 has not reached the charge target SOC set in step S17, the ECU 4a turns the generator on the engine provided in the electric vehicle (hybrid vehicle) until the battery 1 reaches the charge target SOC. 1 is charged. Incidentally, charging can also be performed by obtaining power from a commercial power source (outlet) of an electric power company. Conversely, when the SOC exceeds the appropriate range, the ECU 4a discharges the stored power of the battery 1.
For example, in Tokyo, if the ignition is turned off at 10:00 am on July 30th, the predicted temperature information is obtained and the maximum temperature of the day is found to be 35 ° C, and the SOC corresponds to that temperature. When the charge target SOC to be exceeded is exceeded, the ECU 4a turns the fan of the battery box to lower the SOC and prevents the temperature from rising until the SOC reaches the charge target SOC even after the ignition is turned off. In that case, ECU4a turns the fan which is 12V equipment from the battery 1 through a down converter (not shown). Alternatively, a 12V battery (not shown) may be charged from the battery 1 via a down converter, and the fan may be turned using the 12V battery. Thus, ECU4a charges (discharges) so that it may become SOC corresponding to the 35 degreeC. Incidentally, if the summer temperature is 35 ° C., the temperature of the battery 1 will be higher than that, and this is taken into consideration.
By the way, the predicted temperature information in steps S12 to S15 corresponds to the current time, and the predicted temperature information in step S17 corresponds to the future time.
Further, information on whether the weather at the highest temperature is sunny, cloudy, rainy, etc. may be acquired and reflected in the control. For example, since the battery temperature seems to be higher than the air temperature when it is sunny, the ECU 4a performs control reflecting such a situation. Further, for example, when it is raining, the battery temperature is not expected to be higher than the air temperature, so the ECU 4a performs control reflecting such a situation. This process can also be applied to the first embodiment described above.

  FIG. 7 is a characteristic diagram showing the relationship between the SOC that is left for the start of the next operation after the electric vehicle is stopped and the predicted temperature, the predicted temperature on the horizontal axis, and the charging target at the end of the operation on the vertical axis. It represents the SOC. That is, as shown in FIG. 7, the charging target SOC of the battery 1 for the next start of operation is set higher as the predicted temperature acquired by the communication means (car navigation) 5 is lower, and set lower as the predicted temperature is higher. To do. Of course, as described above, it may be a characteristic diagram considering the types of sunny, cloudy, and rainy.

  FIG. 8 is a flowchart showing a flow of processing for performing battery control based on predicted temperature information acquired by communication means such as a mobile phone in the second embodiment of the present invention. That is, this flowchart shows the flow of processing in which the communication means 5 such as a mobile phone receives external data and acquires the predicted temperature information without using the car navigation function.

  In FIG. 8, the ECU 4a determines whether or not the ignition of the electric vehicle is turned on (step S21). If the ignition is not turned on (No in step S21), the ECU 4a waits until it is turned on. On the other hand, when the ignition is turned on (Yes in step S21), the communication means 5 such as a mobile phone acquires predicted temperature information as external data at the current position and current date and time from a weather system or the like (step S22).

  Next, the ECU 4a determines an upper limit value and a lower limit value of the SOC that can be used in the battery 1 based on the predicted temperature information acquired by the communication unit 5, and sets the usable range of the SOC (step S23). The method for setting the SOC usable range is the same as that in step S14 in FIG. Then, the ECU 4a controls the battery 1 within the usable SOC range, and drives and controls the travel motor 3 via the inverter 2 to drive the electric vehicle (step S24).

Next, the ECU 4a determines whether or not the ignition of the electric vehicle is turned off (step S25). If the ignition is not turned off (No in step S25), the ECU 4a returns to step S22 and repeats the above-described processing. If the ignition is OFF (Yes in step S25), as described in FIG. 6, the ECU 4a predicts the future time of the point based on the position information and date / time information acquired by the communication means (such as a mobile phone) 5. The temperature information (the predicted temperature information ahead of the current time) is acquired, and the charging target SOC of the battery 1 is set to start the next operation based on the predicted temperature information (step S26). The method for acquiring the predicted temperature information at the future time is the same method as any one of (1) and (2) described above in the first embodiment, and the predicted date is estimated at that position with reference to the position and date. The information on the maximum temperature to be obtained is acquired, and the information on the maximum temperature is used as the predicted temperature information. If the SOC of the battery 1 does not reach the charging target SOC set in step S26, the ECU 4a turns the battery generator until the charging target SOC is reached by turning the generator with the engine provided in the electric vehicle (hybrid vehicle). 1 is charged. Incidentally, charging can also be performed by obtaining power from a commercial power source (outlet) of an electric power company. . Conversely, when the SOC exceeds the appropriate range, the ECU 4a discharges the stored power of the battery 1.
By the way, the predicted temperature information in steps S22 to S24 corresponds to the current time, and the predicted temperature information in step S26 corresponds to the future time.
In addition, as described above, information on whether the weather at the highest temperature is sunny, cloudy, rainy, or the like may be acquired and reflected in the control. For example, since the battery temperature seems to be higher than the air temperature when it is sunny, the ECU 4a performs control reflecting such a situation. Further, for example, when it is raining, the battery temperature is not expected to be higher than the air temperature, so the ECU 4a performs control reflecting such a situation.

  That is, as shown in FIG. 7 described above, the upper limit value of the charging target SOC of the battery 1 for the next start of operation is set higher as the predicted temperature searched by the communication means 5 or the car navigation system is lower. Set higher as it gets higher. 7 may be the temperature directly detected from the battery 1 as described in the first embodiment, instead of the predicted temperature searched by the communication unit 5 or the car navigation.

(Effect of 2nd Embodiment)
According to the second embodiment, which is a reference embodiment, by utilizing the relationship between the temperature of the battery 1 and the temperature, the temperature (when the ignition is ON, the predicted temperature at the current time / when the ignition is OFF) The usable range of the battery 1 can be efficiently expanded by changing the usable range of the battery 1 according to the predicted temperature (maximum temperature) at a future time. Moreover, since it is not influenced by the heat generation of the battery 1 or the heat of other in-vehicle electric devices as compared with the actual measurement, a stable usable range can be set.

<< Third Embodiment >>
In the third embodiment of the present invention, a fuel cell system mounted on an electric vehicle will be described. FIG. 9 is a block diagram showing a configuration of a fuel cell system according to the third embodiment of the present invention. The fuel cell system 20 is used, for example, in a hybrid vehicle that runs using the fuel cell 6 and the battery 1 as power sources.
In the third embodiment, similarly to the second embodiment, the temperature of the battery 1 is increased when the air temperature is higher, and conversely, the control using the above-described tendency is lowered when the air temperature is lower. This is an embodiment to be performed. The third embodiment is an embodiment in which the temperature is not measured by a temperature sensor mounted on the vehicle but is acquired from the outside and used for control.

  As shown in FIG. 9, the fuel cell system 20 supplies air to the fuel cell 6, the power distribution device 7, and the fuel cell 6 in addition to the battery 1, the inverter 2, the travel motor 3, the ECU 4 b, and the communication unit 5. An air compressor 8 and a hydrogen supply device 9 for supplying hydrogen to the fuel cell 6 are provided.

  The main power system of the fuel cell system 20 includes a fuel cell 6 and a battery 1 connected in parallel via a power distribution device 7, and a DC voltage output from the power distribution device 7 is converted into a three-phase AC voltage by an inverter 2. It is the place where it is comprised so that the traveling motor 3 may be driven after being converted into. Then, the driving force of the travel motor 3 is transmitted to a tire (not shown) which is a drive wheel via a transmission (not shown), and the electric vehicle is made to travel.

  The fuel cell 6 generates electricity by a chemical reaction between air (oxidant gas) supplied from an air compressor 8 and hydrogen gas supplied from a hydrogen supply device 9 and can supply power to a load such as the traveling motor 3. It is. The battery 1 is connected in parallel with the fuel cell 6, can be charged by receiving generated power from the fuel cell 6 via the power distributor 7, and can supply power to a load such as the traveling motor 3. Is.

  Further, the fuel cell 6 includes a warming-up means 6a that warms up by excessively supplying the reaction gas at a low temperature to increase the power generation amount. Therefore, the battery 1 can store at least a part of the generated electric power when the warm-up means 6a is executed in the SOC usable range.

  The power distribution device 7 distributes output power between the fuel cell 6 and the battery 1 to be supplied to the travel motor 3 based on an output power distribution command (distribution ratio) from the ECU 4b. Therefore, the power distribution device 7 has a built-in DC (Direct current) / DC converter, which is not particularly shown. The travel motor 3 generates a driving force for driving an electric vehicle by rotating a tire (not shown) via a transmission (not shown). When the vehicle is descending, the traveling motor 3 is rotated via a transmission (not shown), and regenerative electric power is generated in the traveling motor 3. This regenerative power is converted into a DC voltage by the reverse conversion action of the inverter 2, and the battery 1 is charged via the power distribution device 7.

  The ECU 4b detects the current I from the current sensor 12 installed in the battery 1 and the voltage V from the voltage sensor 11, calculates the SOC of the battery 1 based on the detected current I and voltage V, and the value of the SOC Based on the above, the power distribution device 7 is instructed to distribute the output power of the fuel cell 6 and the output power of the battery 1. The communication means 5 has a function of using its own communication function, receiving radio waves from a GPS satellite (not shown), and determining its own position on the earth (latitude, longitude, and altitude). , And has a function of acquiring date and time information. Further, the ECU 4b acquires the predicted temperature information that is the temperature information of the position and the date and time based on the position information determined by the communication means (car navigation) 5 and the date and time information, and based on the predicted temperature information, The upper limit value and the lower limit value of the usable SOC are determined. Then, ECU 4b performs battery control while detecting voltage V and current I of battery 1 within the usable range of the SOC. The communication means 5 may have a navigation function, or may have a communication function such as a mobile phone or other communication device. Further, the ECU 4 b acquires the output current of the fuel cell 6 from the current sensor 13 installed in the fuel cell 6, acquires the output voltage of the fuel cell 6 from the voltage sensor 14, and the temperature of the fuel cell 6 from the temperature sensor 15. Can be obtained. Note that the ECU 4b can determine the upper limit voltage and the lower limit voltage of the battery 1 instead of the upper limit value and the lower limit value of the SOC and perform battery control within the voltage range.

  FIG. 10 is a flowchart showing a flow of processing for performing battery control based on predicted temperature information acquired by car navigation in the fuel cell system according to the third embodiment of the present invention.

  In FIG. 10, the ECU 4b determines whether or not the ignition of the electric vehicle is turned on (step S31). If the ignition is not turned on (No in step S31), the ECU 4b waits until the ignition is turned on. On the other hand, when the ignition is turned on (Yes in step S31), the ECU 4b acquires position information, date information, and the like by the communication means (car navigation) 5 (step S32). Further, the ECU 4b acquires the predicted temperature information of the point based on the acquired position information, date / time information, and the like (step S33). The acquisition of the predicted temperature information is performed by any one of the methods (1) and (2) described in the first embodiment.

  Next, the ECU 4b determines an upper limit value and a lower limit value of the SOC that can be used in the battery 1 based on the acquired predicted temperature information, and sets the usable range of the SOC (step S34). Then, the ECU 4b determines whether or not the electric vehicle is at a low temperature start (step S35). If the electric vehicle is at a low temperature start (Yes at step S35), the output of the air compressor 8 is increased (step S36). 6 is increased, and the increased power output is supplied for charging the battery 1. This is because if the temperature is low, the lower limit value is lowered and the SOC range is expanded, so that the chargeable amount of the battery 1 is expanded. Whether or not it is a low-temperature start is performed immediately after the ignition is turned on in step S31 and the ECU 4b determines whether or not the acquired predicted temperature information is equal to or lower than a predetermined temperature. If the engine is not cold start (No in step S35), the ECU 4b skips step S36 and does not increase the output air of the air compressor 8.

Next, the battery 1 is controlled within the SOC usable range set in step S34, and the drive motor 3 is driven and controlled via the inverter 2 to drive the electric vehicle (step S37). Then, it is determined whether or not the ignition of the electric vehicle is turned off (step S38). If the ignition is not turned off (No in step S38), the ECU 4b returns to step S32 and repeats the processing described above. On the other hand, if the ignition is turned off (Yes in step S38), as described in FIG. 6, the ECU 4b uses the position information and date / time information acquired by the communication means (car navigation) 5 at the future time of the point. Expected temperature information (predicted temperature information from the current time) is acquired, and the charging target SOC of the battery 1 is set for starting the next operation based on the predicted temperature information (step S39). The method for acquiring the predicted temperature information at the future time is one of the methods (1) and (2) described in the first embodiment, and is predicted at that position at that position with reference to the position and date and time. Information on the maximum temperature is obtained, and the information on the maximum temperature is used as predicted temperature information. If the SOC of the battery 1 has not reached the charge target SOC set in step S39, the ECU 4b operates the fuel cell 6 to charge the battery 1 until it reaches the charge target SOC. Incidentally, charging can also be performed by obtaining power from a commercial power source (outlet) of an electric power company. On the other hand, when the SOC exceeds an appropriate range, the ECU 4b discharges the stored power of the battery 1.
For example, in Sapporo, if the ignition was turned off at 8:00 pm on January 30th, the predicted temperature information was obtained, and if the minimum temperature of the day was found to be -15 ° C, it corresponded to that -15 ° C. Charging (discharging) is performed so as to obtain SOC. Incidentally, if the winter temperature is −15 ° C., the temperature of the battery 1 is higher than that.
Incidentally, the predicted temperature information in steps S32 to S37 corresponds to the current time, and the predicted temperature information in step S39 corresponds to the future time.
Further, information on whether the weather at the highest temperature is sunny, cloudy, rainy, etc. may be acquired and reflected in the control. For example, when it is sunny, the battery temperature seems to be higher than the temperature, so the ECU 4b performs control reflecting such a situation. Further, for example, when it is raining, it is considered that the battery temperature does not become higher than the air temperature, so the ECU 4b performs control reflecting such a situation.

  FIG. 11 is a flowchart showing a flow of processing in which the ECU 4b controls the power generation output (FC output) of the fuel cell in accordance with the SOC. FIG. 12 is a characteristic diagram showing the relationship between the SOC and the power generation output (FC output) of the fuel cell, with the horizontal axis representing the SOC and the vertical axis representing the FC output.

  In FIG. 11, it is determined whether or not the ignition of the electric vehicle is turned on (step S41). If the ignition is not turned on (No in step S41), the process waits until it is turned on. On the other hand, when the ignition is turned on (Yes in step S41), the ECU 4b acquires predicted temperature information based on position information, date and time information, etc. via the communication means 5 such as a car navigation system or a mobile phone (step S42).

  Next, the ECU 4b determines the upper limit value and the lower limit value of the SOC that can be used in the battery 1 based on the predicted temperature information acquired by the communication means 5, and sets the usable range of the SOC (step S43). . Then, the ECU 4b sets the SOC usage range based on the newly set upper limit value and lower limit value that can be used as 0 to 100%, and calculates the current (after expansion) SOC (step S44).

  Next, the ECU 4b controls the power generation output (FC output) of the fuel cell according to the corrected SOC newly set based on the predicted temperature information (step S45). That is, as shown in the characteristic diagram showing the relationship between the SOC and the FC output shown in FIG. 12, control is performed so that the FC output decreases as the SOC increases.

Next, the ECU 4b controls the battery 1 within the SOC usable range determined in step S45, and drives and controls the travel motor 3 via the inverter 2 to drive the electric vehicle (step S46). Then, the ECU 4b determines whether or not the ignition of the electric vehicle is turned off (step S47). If the ignition is not turned off (No in step S47), the ECU 4b returns to step S42 and repeats the processing described above. On the other hand, if the ignition is turned off (Yes in step S47), as described in FIG. 6, the ECU 4b uses the position information and date / time information acquired by the communication means 5 to predict the predicted temperature information (future time) of the point ( The predicted temperature information (from the current time) is acquired, and the charging target SOC of the battery 1 is set to start the next operation based on the predicted temperature information (step S48). The method for acquiring the predicted temperature information at the future time is the same method as any one of (1) and (2) described above in the first embodiment, and the predicted date is estimated at that position with reference to the position and date. The information on the maximum temperature to be obtained is acquired, and the information on the maximum temperature is used as the predicted temperature information. If the SOC of the battery 1 has not reached the charge target SOC set in step S48, the ECU 4b operates the fuel cell 6 to charge the battery 1 until the charge target SOC is reached. On the other hand, when the SOC exceeds an appropriate range, the ECU 4b discharges the stored power of the battery 1.
Incidentally, the predicted temperature information in steps S42 to S46 corresponds to the current time, and the predicted temperature information in step S48 corresponds to the future time.
Further, information on whether the weather at the highest temperature is sunny, cloudy, rainy, etc. may be acquired and reflected in the control. For example, when it is sunny, the battery temperature seems to be higher than the temperature, so the ECU 4b performs control reflecting such a situation. Further, for example, when it is raining, it is considered that the battery temperature does not become higher than the air temperature, so the ECU 4b performs control reflecting such a situation.

(Effect of the third embodiment)
According to the third embodiment of the present invention, with the expansion of the usable range of SOC in the power storage device, the battery can cope with an excessive power demand of the vehicle, and the upper limit value of the power generation capacity of the fuel cell Therefore, it is possible to prevent the generation of power beyond the above range, so that the fuel efficiency of the vehicle can be improved. In addition, the electric power generated at the time of warming up is not consumed by a resistance load in the electric vehicle system, and the electric power can be effectively used. In addition, since the capacity of the receiving destination of the electric power generated during warm-up increases, the warm-up operation can be performed for a long time. In addition, when the SOC usable range is widened, the battery 1 can discharge a lot when the fuel cell power generation amount is delayed at the time of acceleration. Therefore, the shortage of the power generation amount is compensated to make the driver think that the power is insufficient. You can reduce the number of scenes.

  The usable range determining means and usable range expanding means in the claims include step S3 in the flowchart in FIG. 2, step S14 in the flowchart in FIG. 6, step S23 in the flowchart in FIG. 8, step S34 in the flowchart in FIG. And it implement | achieves by step S43 of the flowchart of FIG. Further, the temperature detection means in the claims includes the temperature sensor 13, the communication means 5, step S2 of the flowchart of FIG. 2, step S13 of the flowchart of FIG. 6, step S22 of the flowchart of FIG. 8, step S33 of the flowchart of FIG. And it implement | achieves by step S42 of the flowchart of FIG. . In addition, when acquiring temperature information (expected temperature information) in this embodiment, it is natural that date information is also necessary in addition to position information.

<Summary>
According to the electric vehicle, the hybrid vehicle, and the fuel cell electric vehicle according to each embodiment of the present invention, when the temperature is low, the battery can be used efficiently by expanding the usable range of the SOC of the battery.
Moreover, according to the electric vehicle, the hybrid vehicle, and the fuel cell electric vehicle according to the embodiments of the present invention, the temperature information of the battery acquired from the temperature sensor installed in the battery, or the car navigation system or the portable device having the communication function is used. Use telephone communication means to obtain the predicted temperature information of the current position, change the upper and lower limit values or both of the SOC based on the temperature information and predicted temperature information, and change the usable range of the SOC. Battery control can be performed by variable control. Alternatively, battery control can be performed by changing both or one of the upper limit voltage and the lower limit voltage of the battery based on the acquired temperature information and predicted temperature information.

  Furthermore, according to the electric vehicle, the hybrid vehicle, and the fuel cell electric vehicle according to each embodiment of the present invention, the battery control system that calculates the SOC by changing the capacity of the battery based on the acquired temperature information and predicted temperature information. It is also possible to construct a system that determines the target SOC for charging the battery after the end of the operation based on temperature information or predicted temperature information.

"effect"
In general, it is known that if a battery is left in a high charge state or high voltage in a high temperature state, the battery deteriorates, and when the temperature is low, deterioration of the battery is suppressed. Then, the electric vehicle system in each embodiment of the present invention detects or estimates the temperature in the battery usage environment, and when the temperature is low, lowers the lower limit value of the SOC of the battery and raises the upper limit value of the SOC, Batteries are used by extending the usable range of SOC. As a result, the capacity of the battery can be used effectively, and the battery life can be prevented from being shortened.

Further, since the internal resistance of the battery increases in an environment where the detected or predicted temperature is low, the output voltage of the battery is limited and the usable range of the SOC becomes narrow. Therefore, the electric vehicle system according to each embodiment of the present invention controls to increase the lower limit value of the SOC at the end of the operation of the electric vehicle when the detected or predicted temperature is expected to be low. Thus, restart can be ensured by increasing the output voltage during the next operation.
Although the position information and the date / time information are used, the date / time information is not always essential. This is because when there is an access from a vehicle that clearly indicates position information, the date and time can be known on the side of the system that received the access.

1 is a configuration diagram of an electric vehicle system according to a first embodiment of the present invention. 5 is a flowchart illustrating a flow of processing for performing battery control based on temperature information acquired by a temperature sensor in the first embodiment of the present invention. It is a characteristic view which shows the relationship between battery temperature and the upper limit of deterioration limit SOC. It is a characteristic view which shows the relationship between battery temperature and the lower limit of deterioration limit SOC. It is a block diagram of the electric vehicle system which concerns on the 2nd Embodiment of this invention. In the 2nd Embodiment of this invention, it is a flowchart which shows the flow of the process which performs battery control based on estimated temperature information. It is a characteristic view which shows the relationship between SOC and predicted temperature which are left for the next driving | operation start after stopping an electric vehicle. It is a flowchart which shows the flow of the process which performs battery control based on the temperature prediction information acquired by communication means, such as a mobile telephone, in the 2nd Embodiment of this invention. It is a block diagram which shows the structure of the fuel cell system which concerns on the 3rd Embodiment of this invention. It is a flowchart which shows the flow of the process which performs battery control based on the estimated temperature information acquired by the car navigation in the fuel cell system which concerns on the 3rd Embodiment of this invention. It is a flowchart which shows the flow of the process which controls the electric power generation output (FC output) of a fuel cell according to SOC. It is a characteristic view which shows the relationship between SOC and the electric power generation output (FC output) of a fuel cell.

Explanation of symbols

1 Battery (power storage device)
2 Inverter 3 Traveling motor 4, 4a, 4b ECU (usable range determination means, power storage device temperature acquisition means and usable range expansion means)
5 Communication means 6 Fuel cell (power generation device, charging device)
6a Warm-up means 7 Power distribution device 8 Air compressor 9 Hydrogen supply device 10a, 10b Electric vehicle system 20 Fuel cell system

Claims (10)

A power storage device;
A charging device;
A travel motor driven by the supply of electric power output from the power storage device;
A fuel cell that is connected in parallel to the power storage device, generates power by supplying a reactive gas, and supplies power to the travel motor;
Usable range determining means for determining the usable range of the amount of power stored in the power storage device;
As the temperature of the temperature or the outside air of the electric storage device is low, an electric vehicle system and a usable range enlarging means for enlarging the usable range,
If the fuel cells are cold start is provided with a warm-up means for warming up by increasing the power generation amount by excessively supplied reaction gas than the non-cold start,
Before Symbol usable range power storage device with a larger usable range by expansion means, an electric vehicle system for power storage at least part of the generated power at the time of execution of said warming-up means,
When the ignition of the electric vehicle is turned off, the predicted temperature information, which is information of the predicted future temperature at the point, is acquired, and the target of the power storage device for starting the next operation based on the acquired predicted temperature information Set the amount of power storage,
When the amount of power stored in the power storage device at the time of ignition OFF does not reach the target power storage amount, the fuel cell is operated to store power in the power storage device until the power storage amount reaches the target power storage amount. ,
An electric vehicle system that discharges stored power of the power storage device when the amount of power stored in the power storage device exceeds the usable range determined based on current temperature information .   The electric vehicle system according to claim 1, wherein the fuel cell, which is a power generation device that supplies electric power to the travel motor, is a hybrid vehicle connected in parallel to the power storage device. The usable range expansion means, the usable range of the enlarged as 100%, the electric vehicle system according to claim 1 or claim 2, characterized in that calculated by percent range of use of the charged amount. The electric vehicle system according to any one of claims 1 to 3, wherein the travel motor also serves as the charging device.   The predicted future temperature is the predicted temperature at the start of the next operation,
  The target power storage amount of the power storage device at the start of the next operation is set higher as the predicted temperature at the start of the next operation is lower, and is set lower as the predicted temperature is higher.
  The electric vehicle system according to any one of claims 1 to 4, wherein the electric vehicle system is provided.   In the acquired predicted temperature information, when the predicted temperature at the point is lower than a predetermined temperature, the lower limit value of the storage amount at the end of the operation of the electric vehicle is set higher than when it is not lower than the predetermined temperature. Do
  The electric vehicle system according to any one of claims 1 to 5, wherein the electric vehicle system is provided.   The electric vehicle system includes:
  A communication means,
  The current temperature information and the predicted temperature information are acquired based on the position information and date / time information acquired by the communication means.
  The electric vehicle system according to any one of claims 1 to 6, wherein the electric vehicle system is provided.   The communication means is car navigation.
  The electric vehicle system according to claim 7.   The communication means is a mobile phone
  The electric vehicle system according to claim 7. A power storage device;
A charging device;
A travel motor driven by the supply of electric power output from the power storage device;
A fuel cell that is connected in parallel to the power storage device, generates power by supplying a reactive gas, and supplies power to the travel motor;
Usable range determining means for determining a usable range of a voltage value between terminals which is an open-circuit voltage value between terminals of the power storage device;
As the temperature of the temperature or the outside air of the electric storage device is low, an electric vehicle system and a usable range enlarging means for enlarging the usable range,
If the fuel cells are cold start is provided with a warm-up means for warming up by increasing the power generation amount by excessively supplied reaction gas than the non-cold start,
Before Symbol usable range power storage device with a larger usable range by expansion means, an electric vehicle system for power storage at least part of the generated power at the time of execution of said warming-up means,
When the ignition of the electric vehicle is turned off, the predicted temperature information, which is information of the predicted future temperature at the point, is acquired, and the target of the power storage device for starting the next operation based on the acquired predicted temperature information Set the voltage value
When the voltage value between the terminals of the power storage device at the time of ignition OFF does not reach the target voltage value, the fuel cell is operated and the power storage device is operated until the voltage value between the terminals reaches the target voltage value. Power storage,
An electric vehicle system that discharges stored power of the power storage device when a voltage value between terminals of the power storage device exceeds the usable range determined based on current temperature information .

Images