JP5811872B2 - Vehicle control device - Google Patents

Description

  The present invention relates to charge control for regenerative energy of a vehicle equipped with a secondary battery or the like as a power source.

  A hybrid vehicle and an electric vehicle are equipped with a secondary battery as a power source for running the vehicle. The secondary battery can charge the regenerative energy during braking while supplying power to the motor for traveling.

  Patent Document 1 is a method for charging regenerative energy of a battery system including means for switching a connection form of a plurality of secondary batteries or capacitors between parallel and series, and a battery with a charge voltage and each connection form The voltage is compared and the series connection is switched to the parallel connection.

JP 2000-59903 A JP 2000-59904 A Japanese Patent Laid-Open No. 5-236608 JP-A-10-94182 JP 2010-57288 A

  However, since the regenerative energy cannot be charged while the connection mode is being switched, the charging efficiency of the regenerative energy is lowered.

  The regenerative energy generated by the travel motor during braking is charged to the secondary battery via the inverter, but energy loss occurs according to the voltage of the inverter. For this reason, there is a problem in that the charging efficiency of regenerative energy decreases when the charging voltage is increased in series connection.

A control device according to a first invention of the present application includes a plurality of power storage devices used as a power source for a vehicle, and controls a vehicle equipped with a series-parallel battery system capable of switching a connection method of the plurality of power storage devices in series and in parallel. Device. The control device switches the regenerative energy by switching the first loss regeneration amount when the current connection method is continuously charged and charging the regenerative energy and the connection method based on the regenerative prediction amount calculated from the running vehicle state information. When the battery is charged, the second loss regeneration amount including the loss in which the regenerative energy cannot be charged during the switching of the connection method is calculated. The calculated first loss regeneration amount and the second loss regeneration amount are compared, and a connection method with a small loss regeneration amount is selected to perform regenerative energy charging control.

  According to the first invention of the present application, the charging control is performed by selecting a connection method (a connection method with a smaller loss regeneration amount) that can charge more regenerative energy, so that the charging efficiency can be improved.

It is a figure which shows the structure of a series-parallel battery system. It is a figure which shows an example of the battery output (regenerative electric power) at the time of parallel connection. It is a figure which shows an example of the loss of regenerative energy at the time of switching a connection system during charge of regenerative electric power. It is a figure which shows an example of charge control of regenerative electric power. It is a figure which shows an example of charge control of regenerative electric power. It is a flowchart which shows the processing flow of charge control of regenerative electric power. It is a figure which shows a modification.

  Examples of the present invention will be described below.

(Example 1)
A battery system (corresponding to a power storage system) that is Embodiment 1 of the present invention will be described. FIG. 1 is a diagram showing the configuration of the battery system of this example. The battery system of the present embodiment can be mounted on a vehicle. Vehicles include hybrid cars and electric cars. The hybrid vehicle includes an engine or a fuel cell as a power source for running the vehicle, in addition to the assembled battery described later. An electric vehicle includes only an assembled battery as a power source for the vehicle.

  The battery system of the present embodiment is a series-parallel battery system capable of switching a plurality of batteries in series and in parallel, and the plurality of batteries are connected by a series-parallel switching circuit. The series-parallel switching circuit includes a plurality of switches, and a plurality of batteries are connected in series or in parallel by ON / OFF control of each switch.

  As shown in FIG. 1, by turning on the switches S1 and S3 and turning off the switch S2, a parallel battery (a high-capacity power supply device) in which two assembled batteries 10a and 10b (battery group) are connected in parallel. ) Is formed. On the other hand, when the switches S1 and S3 are turned off and the switch S2 is turned on, a series battery (high power type power supply device) in which the two assembled batteries 10a and 10b are connected in series is formed.

  In addition, although the example of FIG. 1 has shown the aspect by which the two assembled batteries 10a and 10b are connected by the serial-parallel switching circuit system, the 3 or more assembled batteries are parallel or series by the same connection principle. A series-parallel battery system that can be switched to is also possible. Moreover, although the assembled batteries 10a and 10b comprised by the some cell 11 are connected by the series-parallel switching circuit, the series-parallel battery system which connected the some cell 11 by the series-parallel switching circuit may be sufficient. .

  Each of the assembled batteries 10a and 10b (each corresponding to a power storage device) has a plurality of single cells 11 connected in series. As the cell 11, a secondary battery such as a nickel metal hydride battery or a lithium ion battery can be used. An electric double layer capacitor (capacitor) can be used instead of the secondary battery. The number of the single cells 11 constituting the assembled batteries 10a and 10b can be appropriately set based on the required output. Moreover, the assembled batteries 10a and 10b may include a plurality of single cells 11 connected in parallel.

  The series-parallel battery system of this embodiment is mounted on a vehicle and used as a power source, and can operate a motor / generator 24.

  The assembled batteries 10a and 10b are connected to the inverter 23 via a connection line. When connected in series, the positive terminal of the assembled battery 10a and the inverter 23 are connected via the positive line PL, and the negative terminal of the assembled battery 10b and the inverter 23 are connected to the inverter 23 via the negative line NL. When connected in parallel, the positive terminals of the assembled batteries 10a and 10b and the inverter 23 are connected via the positive line PL, and the negative terminals and the inverter 23 of the assembled batteries 10a and 10b are connected via the negative line NL. Connected to the inverter 23.

  A system main relay SMR-B is provided in the positive electrode line PL, and a system main relay SMR-G is provided in the negative electrode line NL. The assembled batteries 10a and 10b are connected to the motor / generator 24 via system main relays SMR-B and SMR-G, and the SMR-B and SMR-G are turned on (connected) in response to a control signal from the controller 30. State) and off (blocking state). If SMR-B and SMR-G are ON, the power of the battery group of the assembled batteries 10a and 10b is supplied to the motor / generator 24. If SMR-B and SMR-G are OFF, the electric power supplied from the assembled batteries 10a and 10b to the motor / generator 24 is cut off.

  An inverter 23 is provided between the assembled batteries 10 a and 10 b and the motor / generator (MG) 24. The inverter 23 converts the DC power output from the assembled batteries 10 a and 10 b into AC power, and outputs the AC power to the motor / generator 24. For example, a three-phase AC motor can be used as the motor / generator 24. The inverter 23 converts the AC power output from the motor / generator 24 into DC power, and outputs the DC power to the assembled batteries 10a and 10b.

  The motor / generator 24 receives AC power from the inverter 23 and generates kinetic energy for running the vehicle. The motor / generator 24 is connected to wheels, and the kinetic energy generated by the motor / generator 24 is transmitted to the wheels. When the vehicle is decelerated or stopped, the motor generator 24 converts kinetic energy generated during braking of the vehicle into electric energy (AC power). The AC power generated by the motor / generator 24 that operates as a generator during vehicle braking is output to the inverter 23. Thereby, regenerative electric power (regenerative energy) can be stored in the assembled batteries 10a and 10b.

  In the battery system of the present embodiment, the motor / generator 24 can be used as a load that operates by receiving electric power from the assembled batteries 10a and 10b. In the example of FIG. 1, a boost converter may be provided between the assembled batteries 10 a and 10 b and the inverter 23, and the output voltage of the assembled batteries 10 a and 10 b is boosted and then supplied to the inverter 23. Alternatively, the voltage may be supplied to the assembled batteries 10a and 10b after being stepped down.

  Capacitor 22 is connected to positive electrode line PL and negative electrode line NL, and smoothes voltage fluctuations between positive electrode line PL and negative electrode line NL.

  The voltage sensor 20 a detects the voltage (voltage between the positive electrode line PL and the negative electrode line NL) of the entire battery group of the assembled batteries 10 a and 10 b connected in parallel or in series, and outputs the detection result to the controller 30. The voltage sensor 20b is provided in each of the assembled batteries 10a and 10b, detects the voltage between the terminals of each of the assembled batteries 10a and 10b, and outputs the detection result to the controller 30. In addition, the voltage sensor 20b can also detect the voltage of each unit cell 11 connected in series which comprises the assembled batteries 10a and 10b.

  The current sensor 21 is provided in each of the assembled batteries 10 a and 10 b that perform charging and discharging, detects a charging and discharging current, and outputs a detection result to the controller 30. For example, when discharging the assembled batteries 10a and 10b, a positive value can be used as the current value detected by the current sensor 21. Further, when charging the assembled batteries 10a and 10b, a negative value can be used as the current value detected by the current sensor 21.

  The controller 30 is a control device that performs charge / discharge control of the entire assembled batteries 10a and 10b connected in parallel or in series from when the ignition switch of the vehicle is turned on to when it is turned off. The controller 30 charges the assembled batteries 10a and 10b with discharge control for outputting the power of the assembled battery 10 to the load based on the vehicle output request, and regenerative power during vehicle braking when the vehicle decelerates or stops. Perform charging control. The controller 30 of this embodiment includes a series / parallel switching unit 31, a regeneration amount prediction unit 32, a regeneration loss estimation unit 33, and a memory 34.

  The controller 30 can manage the SOC (State of Charge) of each of the assembled batteries 10a and 10b. The SOC indicates the ratio of the current charge capacity to the full charge capacity. The voltage sensor 20a, 20b or the current sensor 21 is used to calculate or specify the SOC of the assembled batteries 10a, 10b, and the memory 34 stores and manages the charge / discharge history and SOC information of the assembled batteries 10a, 10b. be able to.

  The SOCs of the assembled batteries 10a and 10b can be specified from the OCV (Open Circuit Voltage) of the assembled batteries 10a and 10b. Since SOC and OCV are in a correspondence relationship, if this correspondence relationship is obtained in advance, the SOC can be specified from the OCV. The OCV of the assembled batteries 10a and 10b can be calculated from the voltage (CCV: Closed Circuit Voltage) of the assembled batteries 10a and 10b detected by the voltage sensor 20b. On the other hand, the SOC of each of the assembled batteries 10a, 10b is calculated by detecting the charging / discharging currents of the assembled batteries 10a, 10b using the current sensor 21 and integrating the current values at the time of charging / discharging the assembled battery 10. Can do.

  The full charge capacity can be calculated based on the SOC. As an example, start SOC when IG-ON is started to start charge / discharge control, end SOC after IG-OFF is ended and charge / discharge control is completed, and charge / discharge accumulated from IG-ON to IG-OFF The full charge capacity can be calculated using the integrated current value. The full charge capacity can be calculated by “full charge capacity = 100 ÷ (end SOC−start SOC) × charge / discharge current integrated value”.

  Similarly to the SOC, the controller 30 calculates the full charge capacity of each of the battery groups of the assembled batteries 10a and 10b connected by the series / parallel switching circuit, and stores and manages each full charge capacity in the memory 34.

  The series / parallel switching unit 31 controls ON / OFF of the switches S1 to S3, and performs switching control of connection methods (series connection and parallel connection) of the assembled batteries 10a and 10b. For example, the serial system switch control pattern and the parallel system switch control pattern of the switches S1 to S3 of the series / parallel switching circuit can be stored in the memory 34 in advance. The controller 30 can control ON / OFF of the switches S1 to S3 with reference to each switch control pattern, and can perform switching control of the connection method of the assembled batteries 10a and 10b.

  The regeneration amount prediction unit 32 calculates a regeneration prediction amount generated by the motor / generator 24 based on the vehicle state information. The vehicle state information can include, for example, a vehicle traveling speed (vehicle speed), a vehicle deceleration, a depression amount of a brake pedal, and the like. The regeneration amount prediction unit 32 performs regeneration amount prediction processing using the vehicle state information, and the processing result is used by the regeneration loss estimation unit 33. The predicted regeneration amount is a value obtained by predicting the transition of the regeneration amount over time from a predetermined timing for predicting the regeneration amount.

  In this embodiment, for example, a regenerative energy map corresponding to the vehicle speed and deceleration is created in advance, and the regenerative power generated by the motor generator 24 is calculated using the vehicle speed and deceleration input (acquired) by the controller 30. Can be calculated. In this case, the regenerative energy map has a larger value as the vehicle speed is faster and the deceleration is larger, and a smaller value as the vehicle speed is slower and the deceleration is smaller. Further, the predicted regeneration amount can be calculated using a regeneration energy map corresponding to the vehicle speed and the depression amount of the brake pedal.

  When the regenerative power is predicted from the vehicle state information using the regenerative energy map, the vehicle behavior learning value can be used. For example, the deceleration when decelerating from a certain vehicle speed and the depression amount of the brake pedal are learned in advance, and how the behavior of the decelerating vehicle changes with time is accumulated as learning information. The controller 30 predicts the vehicle behavior at the subsequent vehicle speed and deceleration from the learned value from the vehicle speed and deceleration (or the amount of depression of the brake pedal) at a predetermined timing, and predicts the vehicle behavior (vehicle speed and deceleration). ) Can be calculated based on the regenerative energy map.

  Alternatively, the predicted value of the regeneration amount may be calculated using a regeneration energy learning map. For example, the transition of regenerative power is learned in advance from the deceleration start speed, and the regeneration amount within a predetermined time from the vehicle speed at the start of deceleration of the vehicle to after a predetermined time elapses or at the start of deceleration is a predetermined value as time elapses. It is possible to calculate the regenerative amount that predicts the transition of the regenerative amount until. For example, the regeneration energy learning map can be created based on the relationship between the regeneration amount according to the deceleration start speed, with the regeneration amount on the vertical axis and the deceleration start speed on the horizontal axis.

  The regeneration loss estimation unit 33 continues the current connection method from the predicted regeneration amount calculated by the regeneration amount prediction unit 32 and maintains the current connection method to charge the regenerative energy. And the second loss regeneration amount of the regenerative power when the regenerative energy is charged by switching the power.

  FIG. 2 is a diagram illustrating an example of regenerative power input to the assembled batteries 10a and 10b. The horizontal axis is time, and the vertical axis is battery output. When the battery packs 10a and 10b are connected in parallel, the allowable voltage of the battery group is lower than when the battery packs are connected in series. Therefore, the input / output limit value Win (P ) Is set lower than the input / output limit value Win (S) for the battery group of the assembled batteries 10a and 10b in series connection. The input / output limit values Win (P) and Win (S) can be determined in advance according to the battery performance of the assembled batteries 10a and 10b.

  For this reason, as shown in FIG. 2, the input of power larger than the input / output limit value Win (P) is limited, and the regenerative power for the power larger than the input / output limit value Win (P) is connected in parallel. The battery group of the batteries 10a and 10b cannot be charged. Therefore, the regenerative power exceeding the input / output limit value Win (P) at the time of parallel connection becomes the regenerative power that cannot be fully charged, that is, the loss amount a (the portion indicated by the oblique lines in FIG. 2).

  On the other hand, since the allowable voltage of the battery group of the battery packs 10a and 10b connected in series is higher than that when the battery packs 10a and 10b are connected in parallel, the input / output limit of the battery packs 10a and 10b connected in parallel is limited. The input / output limit value Win (S) is set higher than the value Win (P). When the battery groups are connected in series, the battery pack 10a, 10b can be charged with a loss amount a that cannot be recovered by the parallel connection shown by diagonal lines in FIG. 2, but the voltage of the inverter 23 increases. The switching loss in the inverter 23 increases.

  The loss of the switching operation of the semiconductor switch or the like constituting the inverter 23 increases as the input / output voltage of the inverter 23 increases. When the input / output voltage of the battery group of the assembled batteries 10a and 10b is high, the input / output voltage of the inverter 23 also increases. Therefore, when regenerative power is charged by the battery group of the assembled batteries 10a and 10b connected in series, Switching loss increases. This switching loss is a loss amount corresponding to a high voltage relative to the voltage of the battery group connected in parallel, that is, a switching loss occurs in the inverter 23 even when connected in parallel. The switching loss corresponding to the increased voltage at the time of connection can be made the loss amount b.

  Next, as shown in FIG. 3, when regenerative power is charged to the battery groups of the assembled batteries 10 a and 10 b connected in parallel, the connection method of the battery groups is switched in series and is shown by the oblique lines in FIG. 2. Although efficiency can be improved by charging the loss amount a that cannot be recovered by parallel connection, regenerative power cannot be charged while the connection method of the assembled batteries 10a and 10b is being switched (during switching). A loss amount c indicated by hatching in FIG. 3 is a regenerative loss caused by switching the connection method. The switching time from parallel to series or from series to parallel is on / off control of the switches S1 to S3 of the series / parallel switching circuit, so that it can be a fixed time, and the regenerative power during the switching time t is the connection method. The amount of loss c generated by the switching can be made.

  As described above, there is a case where the charging efficiency is not improved even when the connection method of the assembled batteries 10a and 10b is switched by the loss amount c during switching and the loss amount b corresponding to the increased voltage during serial connection. In this embodiment, the loss regeneration amounts a, b, and c are obtained from the predicted regeneration amount calculated by the regeneration amount prediction unit 32, and the current battery group connection method is continued (maintained) to charge the regenerative energy. The first loss regenerative amount of regenerative power in the case of the regenerative power and the second loss regenerative amount of regenerative power when the regenerative energy is charged by switching the connection method, and switching the series-parallel connection of the battery group being regenerated Control and improve charging efficiency.

  FIG. 4 is a diagram illustrating an example of regenerative power charging control according to this embodiment. FIG. 4 shows a case where the battery group of the assembled batteries 10a and 10b at the time of parallel connection charges regenerative power. The controller 30 monitors the battery outputs (regenerative power) of the assembled batteries 10a and 10b connected in parallel or in series using the detection values of the voltage sensors 20a and 20b and the current sensor 21, and regenerates them at a predetermined time interval. It is detected whether or not the regenerative power inside is larger than Win (P).

  When it is determined that the regenerative power is larger than Win (P), the controller 30 performs a regeneration amount prediction process using the vehicle state information. For example, the regenerative prediction amount generated by the motor / generator 24 is calculated from time t1 when it is determined that the regenerative power is greater than Win (P).

  The controller 30 calculates the loss amount a that cannot be charged in parallel connection exceeding Win (P) based on the calculated regeneration prediction amount, and switches the battery group connection method from parallel connection to series connection. The loss amount c during switching and the loss amount b for the increased voltage at the time of series connection are calculated. The controller 30 then regenerates the first loss regeneration amount (loss amount a) when the current battery group is continuously connected in parallel and the regenerative energy when the connection method is switched to the serial connection and charged. The second loss regeneration amount (loss amount b + loss amount c) is compared, and a connection method with a small loss amount is selected.

  In the case of the example of FIG. 4, since the first loss regeneration amount is larger than the second loss regeneration amount in each calculated loss regeneration amount, the current parallel connection is switched to the serial connection, and charging can be completed in the parallel connection from time t1. Control is performed so that the regenerative power corresponding to the loss amount a is not charged. Thus, even if the loss amount c when switching from parallel connection to series connection and the loss amount b for the increased voltage at the time of series connection are taken into account, the loss amount a that cannot be fully charged when the parallel connection is continued. The charging efficiency can be improved by charging the battery.

  Next, the controller 30 determines whether or not the regenerative power is smaller than Win (P) during the charging of the regenerative power in the series-connected battery group after the time t1 when the connection method is switched. When the regenerative power is smaller than Win (P), the loss amount b when the serial connection is continued from time t2 in FIG. 4 and the loss amount c when switching from the serial connection to the parallel connection are calculated from the predicted regeneration amount. . The controller 30 has a first loss regeneration amount (loss amount b) of regenerative energy when the current series connection of the battery group is continuously charged and a regenerative energy first when the connection method is switched to parallel connection and charged. 2. Compare the loss recovery amount (loss amount c) and select a connection method with a small loss amount.

  In the example of FIG. 4, since the first loss regeneration amount is larger than the second loss regeneration amount in each calculated loss regeneration amount, the current series connection is switched to the parallel connection, and regeneration is performed from the time t2 in the battery group connected in parallel. Charge energy. In this case, even if the loss amount c when switching from the series connection to the parallel connection is taken into consideration, the loss amount b when the current series connection is continued can be reduced and the charging efficiency can be improved.

  In FIG. 4, the regenerative prediction process includes a regenerative prediction process from time t1 when it is determined that the regenerative power is larger than Win (P) until the regenerative power becomes smaller than Win (P), and the regenerative power is Win (P The regenerative prediction process from time t2 determined to be smaller than P) until the regenerative power becomes 0 (time t3) is performed separately when the regenerative power is determined to be larger or smaller than Win (P). be able to. Further, when it is determined that the regenerative power is larger than Win (P), the regenerative prediction process from time t1 until the regenerative power becomes 0 (time 3) can be performed.

  FIG. 5 is a diagram illustrating an example of regenerative power charging control according to the present embodiment. The example of FIG. 5 shows a case where the battery group of the assembled batteries 10a and 10b at the time of series connection charges regenerative power. The controller 30 monitors the battery outputs (regenerative power) of the assembled batteries 10a and 10b connected in parallel or in series using the detection values of the voltage sensors 20a and 20b and the current sensor 21, as in the example of FIG. And it is detected whether regenerative electric power is smaller than Win (P).

  The controller 30 performs a regeneration amount prediction process using the vehicle state information at a timing when it is determined that the regenerative power is smaller than Win (P). For example, the regenerative prediction amount generated by the motor / generator 24 is calculated from time t4 when it is determined that the regenerative power is smaller than Win (P).

  The controller 30 calculates a loss amount b, which is a switching loss corresponding to an increase in voltage at the time of series connection, and calculates a loss amount c during switching when switching from series connection to parallel connection. Then, the controller 30 regenerates energy when the first loss regeneration amount (loss amount b) of regenerative energy when the current battery group is continuously connected in series and when the connection method is switched to parallel connection and recharged. The second loss regeneration amount (loss amount c) is compared, and a connection method with a small loss amount is selected.

  In the case of the example in FIG. 5, the first loss regeneration amount is larger than the second loss regeneration amount. Therefore, the current series connection is switched to the parallel connection, and the regenerative power is charged from time t4. Even considering the loss amount c when switching from the series connection to the parallel connection, the loss amount b when the series connection is continued can be reduced to improve the charging efficiency.

  FIG. 6 is a diagram illustrating a processing flow of regenerative energy charging control according to the present embodiment. Regenerative energy charging control is performed by the controller 30.

  In the charge / discharge control after turning on the ignition switch of the vehicle, the controller 30 acquires vehicle state information and detects, for example, whether the vehicle is running from the vehicle speed (S101, S102). When the vehicle is running, the controller 30 determines whether or not the regenerative energy generated by the motor / generator 24 is being charged (regenerating) from the deceleration and the amount of depression of the brake pedal (S103). When regeneration is not being performed, discharge control for supplying power to the inverter 23 is performed.

  Whether or not the battery is being regenerated is determined based on the battery outputs (regenerative power) of the assembled batteries 10a and 10b connected in parallel or in series using the detection values of the voltage sensors 20a and 20b and the current sensor 21. It can also be performed by monitoring and detecting whether or not the regenerative power has a negative value.

  When it is determined in step S103 that regeneration is in progress, the controller 30 acquires the current regeneration amount. The regenerative amount charged in the assembled batteries 10a and 10b can be acquired from the monitored power output. The controller 30 determines whether or not the acquired regeneration amount is larger than the input / output upper limit value Win (P) at the time of parallel connection. If larger, the process proceeds to step S106, and if smaller, the process proceeds to step S114.

  In step S106, the controller 30 confirms the current connection method of the battery group of the assembled batteries 10a and 10b. If the connection method is series connection, the process proceeds to step S115, and the current battery group connection method is continued (not switched from series connection to parallel connection).

  On the other hand, when the current battery group connection method of the assembled batteries 10a and 10b is parallel connection in step S106, the process proceeds to step S107, and the controller 30 performs regeneration amount prediction processing.

  In step S108, the controller 30 determines that the SOC of the battery group of the assembled batteries 10a and 10b is a predetermined full charge capacity (upper limit SOC) without switching the connection method based on the predicted regeneration amount and the SOC of the assembled batteries 10a and 10b. It is determined whether or not. For example, when the predicted regenerative power exceeds Win (P), the loss amount a that cannot be charged by parallel connection is calculated, and the regenerative power obtained by subtracting the loss amount a from the calculated regenerative prediction amount is charged. It is determined whether or not the SOC of the battery groups 10a and 10b reaches a predetermined full charge capacity.

  If it is determined that the SOC of the battery group of the assembled batteries 10a and 10b reaches a predetermined full charge capacity without switching the connection method, the controller 30 proceeds to step S115 and continues the current battery group connection method. (Do not switch from serial connection to parallel connection).

  In this way, when the SOC of the battery group of the assembled batteries 10a and 10b reaches a predetermined full charge capacity without switching the connection method, the current battery group connection method is continued and the switching operation of the series-parallel switching circuit is performed. Since it can suppress, consumption deterioration of switch S1-S3 can be suppressed. The same applies to step S117 described later.

  In step S108, when it is determined that the SOC of the battery group of the assembled batteries 10a and 10b does not reach a predetermined full charge capacity, the controller 30 cannot perform a loss amount that cannot be charged in parallel connection in which regenerative power exceeds Win (P). a and a loss amount c during switching when the battery group connection method is switched from parallel connection to series connection, and a loss amount b corresponding to the increased voltage at the time of series connection, respectively. Regenerative energy loss regenerative amount A (loss amount a) when the battery group is continuously connected in parallel and regenerative energy loss regenerative amount B (loss amount b +) when charging is performed by switching the connection method to series connection. Loss amount c) is calculated (S109, S110).

  The controller 30 compares the loss regeneration amount A calculated in step S111 with the loss regeneration amount B, and determines a connection method with a small loss amount. When the loss regeneration amount A is larger than the loss regeneration amount B, the process proceeds to step S112, and the connection method is switched from the current parallel connection to the series connection to charge the regenerative power. On the other hand, if the loss regeneration amount A is smaller than the loss regeneration amount B, the process proceeds to step S113, and the current parallel connection is continued and the regenerative power is charged without switching the connection method.

  Next, when it is determined that the regeneration amount acquired in step S105 is smaller than the input / output upper limit value Win (P) at the time of parallel connection, the controller 30 proceeds to step S114 and similarly to step S106, the current assembled battery Check the connection method of the battery groups 10a and 10b.

  When the acquired regeneration amount is smaller than the input / output upper limit Win (P) at the time of parallel connection and the connection method is parallel connection, the controller 30 proceeds to step S115 and continues the current battery group connection method. Charge the regenerative power (without switching from parallel to series connection).

  On the other hand, in step S114, if the current battery group connection method of the assembled batteries 10a and 10b is series connection, the process proceeds to step S116, and the controller 30 performs the regeneration amount prediction process in the same manner as in step S107.

  In step S117, the controller 30 sets the SOC of the battery group of the assembled batteries 10a, 10b to a predetermined full charge capacity (upper limit SOC) without switching the connection method based on the predicted regeneration amount and the SOC of the assembled batteries 10a, 10b. It is determined whether or not. For example, when the loss amount b for the increased voltage at the time of series connection is calculated, and the regenerative power obtained by subtracting the loss amount b from the calculated predicted regeneration amount is charged, the SOC of the battery group of the assembled batteries 10a and 10b Determines whether or not the battery reaches a predetermined full charge capacity.

  If it is determined that the SOC of the battery group of the assembled batteries 10a and 10b reaches a predetermined full charge capacity without switching the connection method, the controller 30 proceeds to step S115, and the current battery group connection method (series connection) ) To continue charging the regenerative power.

  In step S117, when it is determined that the SOC of the battery group of the assembled batteries 10a and 10b does not reach the predetermined full charge capacity, the controller 30 determines that the voltage at the time of series connection is high based on the calculated predicted regeneration amount. When the loss amount b which is the switching loss corresponding to the calculated amount is calculated, the loss amount c during switching when switching from the series connection to the parallel connection is calculated, and the current series connection of the battery group is continuously charged Regenerative energy loss regenerative amount C (loss amount b) and regenerative energy loss regenerative amount D (loss amount c) when the connection method is switched to parallel connection and charging is calculated (S118, S119).

  In step S120, the controller 30 compares the calculated loss regeneration amount C with the loss regeneration amount D to determine a connection method with a small loss amount. When the loss regeneration amount C is larger than the loss regeneration amount D, the process proceeds to step S121, and the connection method is switched from the current series connection to the parallel connection to charge the regenerative power. On the other hand, when the loss regeneration amount C is smaller than the loss regeneration amount D, the process proceeds to step S122, and the current series connection is continued and the regenerative power is charged without switching the connection method.

  In this embodiment, the loss regeneration amount when the current connection method is continuously charged from the predicted value of the regeneration amount is compared with the loss regeneration amount of the regenerative energy when the connection method is switched and charged. Thus, charging efficiency can be improved by performing charging control of regenerative power in which a connection method with a small loss regeneration amount is selected.

  That is, since the regenerative energy charging control is performed by selecting a connection method that can charge more regenerative energy from the viewpoint of the loss regenerative amount, the regenerative energy can be efficiently charged while suppressing the loss regenerative amount.

  FIG. 7 is a diagram showing a modification of the battery system of the present embodiment. As shown in FIG. 7, the battery groups of the assembled batteries 10a and 10b connected by the series-parallel switching circuit shown in FIG. 1 are connected in parallel to the inverter 23 via the positive electrode line PL1 and the negative electrode line NL1. The assembled battery 10c is provided. System main relays SMR-B1 and SMR-G1 are provided on positive line PL1 and negative line NL1, respectively.

  In the modification shown in FIG. 7, the controller 30 controls the rechargeable power corresponding to the loss amount c generated when switching the connection method of the battery groups of the assembled batteries 10 a and 10 b to charge the assembled battery 10 c. Can do.

  For example, in the switching control of the connection method in steps S112 and S121 of FIG. 6, the controller 30 controls the positive line PL and the negative line NL connected to the battery group of the assembled batteries 10a and 10b at the start of the switching operation. The system main relays SMR-B and SMR-G are switched from ON to OFF, and the system main relays SMR-B1 and SMR-G1 of the positive line PL1 and the negative line NL1 connected to the assembled battery 10c are switched from OFF to ON. Charging of the regenerative power to the battery group of the assembled batteries 10a and 10b in operation is interrupted, and the assembled battery 10c is charged.

  The controller 30 turns the system main relays SMR-B1 and SMR-G1 from ON to OFF at the end of the switching operation, and turns the system main relays SMR-B and SMR-G from OFF to ON, and the assembled batteries 10a and 10b after the switching operation. Charging of the regenerative power to the battery group is resumed, and charging to the assembled battery 10c is interrupted.

  In the modification shown in FIG. 7, part or all of the regenerative power corresponding to the loss amount c generated when switching the connection method of the battery groups of the battery packs 10a and 10b can be charged to the battery pack 10c. The charging efficiency of the regenerative energy generated by the generator 24 is improved. 7 can also be applied to the regenerative energy charging control process flow shown in FIG. 6, and the controller 30 switches the connection method in steps S112 and S121 of FIG. 6 as described above. The regenerative electric power in the battery pack is charged into the assembled battery 10c, and the loss amount c generated when the connection method of the battery groups of the assembled batteries 10a and 10b is switched in the calculation of the lost regeneration amount and the comparison of the calculated lost regeneration amount is excluded. Then, control is performed to switch to a connection method with a small loss regeneration amount.

10a, 10b Battery pack 11 Cell 20a, 20b Voltage sensor 21 Current sensor 22 Capacitor 23 Inverter 24 Motor generator 30 Controller 31 Series / parallel switching unit 32 Regeneration amount prediction unit 33 Loss estimation unit 34 Memory

Claims (5)

A vehicle control device including a plurality of power storage devices used as a power source of a vehicle, and equipped with a series-parallel battery system capable of switching a connection method of the plurality of power storage devices in series and parallel,
When the regenerative energy is charged by continuously switching the current connection method and the regenerative energy is charged by switching the connection method based on the predicted regeneration amount calculated from the running vehicle state information. And calculating a second loss regeneration amount including a loss that cannot be recharged during switching of the connection method , and comparing the calculated first loss regeneration amount and the second loss regeneration amount, the loss regeneration amount is small. A control device for a vehicle, wherein a regenerative energy charging control is performed by selecting a connection method. When the current connection method is parallel connection, when regenerative energy is charged by continuing parallel connection, the first loss regeneration amount that cannot be recovered by parallel connection and the connection method are switched to serial connection to regenerate energy. When the battery is charged, the second loss regeneration amount including a loss that cannot be recharged during switching of the connection method and a loss of voltage that is increased by switching from parallel connection to series connection is characterized. The vehicle control device according to claim 1. When the current connection method is a series connection, when the regenerative energy is charged by continuing the series connection, the first loss regeneration amount generated by the higher voltage than the parallel connection and the series method to the parallel connection 2. The vehicle control device according to claim 1, wherein when the regenerative energy is charged by switching, the second loss regeneration amount that is a loss that cannot be recharged during the switching of the connection method is compared. The SOC of the plurality of power storage devices in the current connection method is obtained by charging the regenerative energy obtained by subtracting the first loss regeneration amount when the current connection method is continuously charged from the regenerative prediction amount. 4. It is determined whether or not an upper limit SOC is reached, and when it is determined that the upper limit SOC is reached, control is performed so as to continue the current connection method. Vehicle control device. A vehicle control device including a plurality of power storage devices used as a power source of a vehicle, and equipped with a series-parallel battery system capable of switching a connection method of the plurality of power storage devices in series and parallel,
When the regenerative energy is charged by continuously switching the current connection method and the regenerative energy is charged by switching the connection method based on the predicted regeneration amount calculated from the running vehicle state information. And calculating the second loss regeneration amount, comparing the calculated first loss regeneration amount and the second loss regeneration amount, selecting a connection method with a small loss regeneration amount, and performing charging control of regeneration energy,
The series-parallel battery system is a sub power storage connected in parallel to a current path of regenerative energy charged in the plurality of power storage devices separately from the plurality of power storage devices switched to each connection method of serial connection and parallel connection. Further comprising a device,
A control apparatus for a vehicle, wherein regenerative energy that cannot be charged to the plurality of power storage devices during connection mode switching is controlled to charge the sub power storage devices.

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