Battery control system

Abstract

An allowable power calculation unit 153 calculates allowable power on the basis of a measurement result of an operation state of a battery, an allowable power limitation unit 154 determines whether limitation of the allowable power is necessary and outputs the allowable power limited by a vehicle control unit 200 on the basis of a determination result, and a notification unit 155 notifies the vehicle control unit 200 of the operation state of the battery on the basis of the determination result.

Description

Battery control system

[0007]

[0001] The present invention relates to a battery control system for an electric vehicle or the like.

[0002] A battery control system for controlling the charge and discharge of a secondary battery for a driving target such as an electric vehicle is known. As an index indicating how much power a battery can output or the power that a vehicle system can use, there is "allowable power". That is, the allowable power is the maximum power that can be used in the driving target. The driving target is operated so that the power consumption is within the allowable power.

[0003] The allowable power consists of the allowable power in the charging direction (charging allowable power) and the allowable power on the discharging side (discharging allowable power), and each is calculated by the battery control system. During charging, the charging allowable power decreases, and conversely, the discharging allowable power increases. During discharging, the discharging allowable power decreases, and the charging allowable power increases.

[0004] In the system of an electric vehicle, the maximum operating voltage and the minimum operating voltage are determined, and the allowable power that can be used within that range is calculated. For example, the discharging allowable power is obtained by taking into account the difference from the current battery voltage until the minimum operating voltage (which is often higher than the over-discharge voltage).

[0005] Patent Document 1 describes that in order to provide a battery control device that can keep the terminal voltage of each single battery within the allowable range while controlling the allowable power in units of battery packs, the allowable power of the battery pack is limited according to the degree to which the closed-circuit voltage of the single battery approaches the upper limit or the lower limit of the allowable range.

[0006] WO2012 / 157065 publication

[0007] If an abnormal operating condition occurs in a vehicle's battery, the battery control system is required to promptly limit the allowable power. However, unlike hybrid vehicles, electric vehicles do not have an engine as a power source other than the battery, so a sudden limitation of the battery's allowable power may impair the vehicle's operation. On the other hand, a delay in limiting the allowable power may lead to battery damage. There are concerns that this type of problem will become more pronounced as vehicle batteries are used for extended periods and degrade over time.

[0008] Therefore, the present invention aims to provide a battery control system that can quickly protect a battery in the event of abnormal battery operation, while preventing the operation of the driven object from being suddenly restricted.

[0009] To achieve the above objective, the present invention provides a battery control system for controlling the charging and discharging of a battery, comprising: an allowable electrical characteristics calculation unit for calculating the allowable electrical characteristics of the battery; a determination unit for determining whether it is necessary to limit the calculated allowable electrical characteristics; a limitation execution unit for limiting the calculated allowable electrical characteristics based on the determination result of the determination unit and outputting the limited allowable electrical characteristics to a control unit of a driven object; and a notification unit for notifying the control unit of the operating state of the battery based on the determination result of the determination unit.

[0010] According to the present invention, it is possible to provide a battery control system that can quickly protect a battery in the event of abnormal battery operation, while preventing the operation of the driven object from being suddenly restricted.

[0011] This is a hardware block diagram of a battery control system according to an embodiment of the present invention. This is a functional block diagram showing the BMS of the battery control system (Figure 1). This is a functional block diagram showing the allowable power processing unit. This is a block diagram of the equivalent circuit model of the battery. This is a characteristic diagram explaining the operation of the allowable power limiting unit. This is a second characteristic diagram explaining the operation of the allowable power limiting unit. This is a second example of a functional block diagram of the allowable power processing unit.

[0012] Hereinafter, embodiments for carrying out the present invention will be described with reference to the figures. Figure 1 is a hardware block diagram of a battery control system according to an embodiment of the present invention. Electric vehicles (EVs), hybrid electric vehicles (HEVs), trains, industrial equipment, etc., are envisioned as the driving targets of the battery control system 100. Figure 1 shows a system that supplies power to a motor generator 410 for driving an EV.

[0013] The battery control system 100 is connected to the inverter 400 via relays 300 and 310. The inverter 400 supplies power from the battery pack 110 (battery module) to the motor generator 410. The inverter 400 and the motor generator 410 are controlled by the motor / inverter control unit 420. The vehicle control unit 200 determines the distribution of driving force, etc., based on the battery information obtained from the battery control system 100 and the information from the inverter 400 and the motor generator 410. By making the inverter 400 a bidirectional inverter, the power output by the motor generator 410 can be stored in the battery pack 110.

[0014] The battery control system 100 includes a battery pack 110 composed of a plurality of individual cells 111, a measurement unit 120 equipped with a plurality of individual cell control units 121 (121a, 121b) that monitor the state of the individual cells 111, a current detection unit 130 that detects the current flowing through the battery pack 110, a voltage detection unit 140 that detects the total voltage of the battery pack 110, a BMS (Battery Management System) 150 for the battery pack 110, and a storage unit 180 that stores information regarding the battery characteristics of the battery pack 110, individual cells 111, and individual cell groups 112 (112a, 112b).

[0015] The multiple individual cells 111 that make up the battery pack 110 are grouped into predetermined units. In the example shown in Figure 1, the multiple individual cells 111 are grouped into two cell groups 112a and 112b. The cell groups 112a and 112b are electrically connected in series.

[0016] The single cell 111 is a rechargeable secondary battery such as a lithium-ion battery. Other possible single cells 111 include nickel-metal hydride batteries, lead-acid batteries, electric double-layer capacitors, and devices with energy storage capabilities. Here, we are considering a single cell 111, but it is also possible to replace the single cell 111 with a module structure in which multiple cells are connected in series or parallel. Hereafter, "single cell" may simply be referred to as "battery".

[0017] In the example shown in Figure 1, the battery pack 110 is configured with two single cell groups 112a and 112b connected in series. However, it is not limited to this configuration, and a predetermined number of single cell groups may be connected in series or in parallel. Furthermore, various combinations of series and parallel connections may be used depending on the application.

[0018] The measurement unit 120 monitors the state of each individual cell 111 that makes up the battery pack 110. A number of individual cell control units 121a and 121b are provided, corresponding to multiple individual cell groups 112a and 112b. Each individual cell control unit 121a is assigned to an individual cell group 112a, and each individual cell control unit 121b is assigned to an individual cell group 112b. Each individual cell control unit 121a and 121b operates by receiving power from the individual cell groups 112a and 112b to which it is assigned. Each individual cell control unit 121a and 121b monitors the battery voltage and battery temperature of the individual cell groups 112a and 112b to which it is assigned.

[0019] The BMS 150 receives the current value flowing through the battery pack 110 transmitted from the current detection unit 130 and the total voltage value of the battery pack 110 transmitted from the voltage detection unit 140. The BMS 150 transmits and receives signals with the measurement unit 120 via the signal communication unit 160, and receives from the measurement unit 120 the battery voltage and temperature of the individual cells 111, as well as diagnostic results on whether the individual cells 111 are overcharged or over-discharged, and abnormal signals output when a communication error occurs in the measurement unit 120. The BMS 150 performs processing such as estimating the battery state based on the input information, and the processing results are transmitted to the measurement unit 120 and the vehicle control unit 200. The BMS 150 performs numerical calculations for state estimation calculations such as SOC, SOH, and allowable power.

[0020] The signal communication unit 160 is provided with an insulating element 170, such as a photocoupler. As described above, the measurement unit 120 operates by being powered by the battery pack 110. Since the BMS 150 uses a battery for onboard auxiliary equipment (for example, a 12V battery) as its power source, the reference potentials of the operating power supplies for the BMS 150 and the measurement unit 120 are different. For this reason, an insulating element 170 is provided in the signal communication unit 160. The insulating element 170 may be mounted on the circuit board constituting the measurement unit 120, or on the circuit board constituting the BMS 150. It is also possible to omit the insulating element 170.

[0021] The single-cell control units 121a and 121b are connected in series according to the order of decreasing potential of the single-cell groups 112a and 112b that they each monitor. An insulating element 170 is not provided between the output of single-cell control unit 121a and the input of single-cell control unit 121b because the single-cell control units 121a and 121b are equipped with a mechanism that allows communication even between units with different operating reference potentials. However, if electrical isolation is required for communication between single-cell control unit 121a and single-cell control unit 121b, an insulating element 170 must be provided.

[0022] The signal transmitted by the BMS 150 is input to the single cell control unit 121a by the signal communication unit 160, which is equipped with an insulating element 170. The output signal from the single cell control unit 121b is transmitted to the input section of the BMS 150 by the signal communication unit 160, which is equipped with an insulating element 170. In this way, the BMS 150 and the single cell control units 121a and 121b are connected in a loop by the signal communication unit 160. This type of connection and communication method is called a daisy-chain connection, but it is also sometimes called a chain connection or a daisy-chain connection.

[0023] The memory unit 180 stores information such as internal resistance characteristics, capacity at full charge, polarization resistance characteristics, degradation characteristics, individual difference information, and the correspondence between the battery open-circuit voltage OCV and the battery's state of charge (SOC) (OCV-SOC map) for the battery pack 110, individual cells 111, and group of individual cells 112. The memory unit 180 can also store battery parameter information (battery information dynamically obtained by the system, such as charge rate, degradation rate, allowable current, and allowable power) acquired when the battery control system is operating, or at the start or end of operation. In the example shown in Figure 1, the memory unit 180 is configured to be located outside the BMS 150 and the measurement unit 120, but the memory unit 180 may also be provided in the BMS 150 or the measurement unit 120.

[0024] The memory unit 180 can store information about the dynamic battery control system obtained from the BMS 150 and the measurement unit 120 as needed. That is, information related to battery control system failures and battery status is newly acquired while the battery control system is operating or when the battery control system starts up or stops up. This information can be used to estimate the battery status when the battery control system is started up again, or to analyze failures when offline. The information may be stored as is, or as statistical information such as mean, standard deviation, and variance. It may also be stored permanently as historical information.

[0025] (Configuration of BMS150) Figure 2 is a functional block diagram showing the BMS150. The BMS150 comprises a battery state calculation unit 151 and an allowable power processing unit 152. The battery state calculation unit 151 calculates and outputs the SOC (State of Charge: Battery Operation Index) and SOHR (Sweet Oxide Rate) as battery states based on the output from detection units (measurement unit 120, current detection unit 130, voltage detection unit 140) that detect battery operation information (operational information). The BMS150 realizes functional modules such as the battery state calculation unit 151 by having control resources such as a processor and controller mounted on an integrated circuit board execute a program. The "unit" in "allowable power calculation unit, etc." may be replaced with terms such as module, means, unit, or block.

[0026] The allowable power processing unit 152 takes the SOC and SOHR, which are outputs of the battery state calculation unit 151, and battery operation information (voltage, current, temperature) as input, and determines the allowable charge power (the margin power value up to the upper limit of the voltage at which charging is possible) and the allowable discharge power (the margin power value up to the lower limit of the voltage at which discharge is possible), and outputs them to the vehicle control unit 200. Furthermore, as will be described later, the allowable power processing unit 152 creates notification information when determining the allowable power and outputs it to the vehicle control unit 200. The voltage, current, and temperature input to the battery state calculation unit 151 and the allowable power processing unit 152 are representative values ​​representing the battery operation of the battery pack 110 obtained by the single cell control units 121a, 121b and the current detection unit 130.

[0027] The voltage data shows information about the variation and average of individual batteries 111, including the maximum voltage, average voltage, and minimum voltage. The current data shows the instantaneous current acquired at the same time as the battery voltage acquisition, or the interval average current obtained by continuously sampling the current flowing through the battery pack 110 over a certain time interval and averaging the current values ​​from multiple samples. The temperature data shows the maximum temperature, average temperature, and minimum temperature obtained by multiple temperature sensors placed within the battery pack 110, taking into account the temperature distribution of the battery pack 110, the group of individual batteries 112, or the individual batteries 111. These voltages, currents, and temperatures are used as needed to calculate the State of Charge (SOC), State of Heat Recovery (SOHR), and allowable power (charge allowable power and discharge allowable power).

[0028] Figure 3 is a functional block diagram showing the allowable power processing unit 152. The allowable power processing unit 152 comprises an allowable power calculation unit 153, an allowable power limiting unit 154, and a notification unit 155. The allowable power calculation unit 153 calculates the allowable power of the battery using SOC, SOH, voltage, current, and temperature as input. The allowable power limiting unit 154 determines whether or not to limit the allowable power based on the allowable power output from the allowable power calculation unit 153, using SOC, voltage, current, and temperature (limiting determination unit 154A), and implements a limit on the allowable power according to the determination result (limiting execution unit 154B). The notification unit 155 creates notification information related to abnormal battery operation states based on overvoltage conditions and overtemperature conditions based on the determination result of the limiting determination unit 154A, and notifies the vehicle control unit 200 of this information.

[0029] The vehicle control unit 200 not only suppresses the power consumption of the motor generator 410 by receiving the limited allowable power from the limiting execution unit 154B, but also knows from the notification information from the notification unit 155 that the battery is in an abnormal operating state or a state close to it. As a result, it can quickly suppress the power consumption of the motor generator 410 in order to avoid sudden changes in the operating state of the vehicle.

[0030] To distinguish between the final allowable power from the allowable power limiting unit 154 and the allowable power before limiting from the allowable power calculation unit 153, the charge allowable power output from the allowable power calculation unit 153 will be called the post-calculation charge allowable power, and similarly, the discharge allowable power will be called the post-calculation discharge allowable power.

[0031] (Calculation of allowable power: Allowable power calculation unit 153) The allowable power calculation unit 153 estimates the allowable power using an equivalent circuit model of the battery, based on battery operation information (voltage, temperature, current, etc.) and battery state indicators (SOC, SOHR). Figure 4 is a block diagram of the equivalent circuit model. The equivalent circuit model consists of a battery open-circuit voltage OCV, a DC resistance Ro, and a CR parallel circuit (time constant τ) of polarization resistance Rp and polarization capacitance component connected in series.

[0032] The battery voltage V (CCV) is given by equation (1) when a current I flows through the battery. The polarization voltage Vp in equation (1) is the voltage generated when a current I flows through the CR parallel circuit consisting of a polarization resistor Rp and a polarization capacitance component.

[0033] This section explains how to calculate the charge capacity. The charge capacity per battery is the product of the maximum current that can flow through the battery in its current state (charge capacity current Imax, chg) and the charge capacity voltage Vmax, chg generated when that current flows through the valence circuit model. Since the battery pack 110 is composed of N single cells 111 connected in series, the discharge capacity is determined by multiplying this product by N for each cell.

[0034] The allowable charging currents Imax and chg are determined. The basic calculation formula for the allowable charging current is shown below as equation (2). The allowable charging current Ichg is the current that flows when the voltage V is equal to the upper limit voltage Vmax used by the system in the battery equivalent circuit model in Figure 4. Equation (2) is obtained by transforming equation (1) for the current I. However, the battery open-circuit voltage OCV is obtained from the current SOC and temperature T using an OCV map that shows the correspondence between SOC and battery temperature. The DC resistance Ro is obtained using the Ro map obtained from the correspondence between SOC and temperature T. This Ro map is composed of values ​​for a new battery and does not take into account the case when the battery has deteriorated. Therefore, by multiplying Ro by the SOHR, which is the battery deterioration rate, we obtain Ro that takes into account the current deterioration state of the battery.

[0035] The rechargeable current Ichg obtained in equation (2) is the maximum current that can flow through the battery. However, a current above the upper limit Ilimit cannot be supplied, even if there is a margin in the battery's performance.

[0036] Equation (3) represents the allowable charging current Imax,chg, with the upper limit current Ilimit set to the maximum current. The allowable charging current Ichg obtained from the equivalent circuit model is limited so as not to exceed the upper limit current Ilimit. In this way, the allowable charging current Imax,chg can be obtained.

[0037] Equation (4) is an equation that shows the allowable charging voltage Vmax, chg. It is the voltage V when the allowable charging current Imax, chg is passed through the equivalent circuit model in Figure 4, and is calculated by substituting it into equation (1). Similar to the allowable charging current Imax, chg, the OCV is calculated using the OCV map. The Ro calculated from the Ro map of a new battery is multiplied by the battery degradation rate SOHR to take into account the current battery degradation and bring it closer to the actual Ro.

[0038] The allowable power per battery is obtained by multiplying the charging allowable voltage Vmax,chg and the charging allowable current Imax,chg obtained above. Considering that there are N battery units in the battery pack 110, the calculated post-charging allowable power Wchg, which is the output of the allowable power calculation unit 153 in the first embodiment, can be obtained by Equation (5).

[0039] The method for calculating the discharge allowable power will be described. The discharge allowable power per battery is represented by the product of the maximum current that can flow: the discharge allowable current Imax,dis, and the voltage that occurs when this current flows through the battery equivalent circuit model: the discharge allowable voltage Vmax,dis. Considering that the battery pack 110 is composed of N single batteries 111 connected in series, the discharge allowable power in the first embodiment can be obtained by multiplying this by N times the number of battery units.

[0040] The discharge allowable current Imax,dis is obtained. Equation (6) shows the basic calculation formula for the discharge allowable current. Here, the dischargeable current is defined as Idis. The dischargeable current can be obtained as the current that flows when the voltage V is equal to the lower limit voltage Vmin used by the system in the battery equivalent circuit model of FIG. 4. Therefore, Equation (6) can be obtained by transforming Equation (1) with respect to the current I. The basic calculation content is the same as the chargeable current Ichg in Equation (2), but considering that the direction of the current is opposite, the equation is transformed so that Idis becomes a positive value.

[0041] Equation (7) represents the discharge allowable current Imax,dis obtained by restricting the upper limit current Ilimit of the system as the maximum current, similar to the calculation of the charging allowable current Imax,chg. It is restricted so that it does not exceed the upper limit current Ilimit in the system with respect to Idis obtained from the battery equivalent circuit model. In this way, the discharge allowable current Imax,dis can be obtained.

[0042] Equation (8) is an equation indicating the discharge allowable voltage Vmax,dis. The discharge allowable current Imax,dis is the voltage V when flowing through the battery equivalent circuit model in Fig. 4 and is calculated by applying it to Equation (1). Similar to Imax,dis, the OCV is calculated using the OCV map. Also, for Ro calculated from the Ro map of a new battery, the degradation rate SOHR of the battery is multiplied to approximate the actual Ro by taking into account the current battery degradation.

[0043] The allowable power per battery is obtained by multiplying the discharge allowable voltage Vmax,dis and the discharge allowable current Imax,dis obtained above. Considering that this is for N battery cells of the battery pack 110, the calculated post-discharge allowable power Wdis, which is the output of the allowable power calculation unit 153 in the first embodiment, is obtained by Equation (5).

[0044] (Allowable Power Limiting Unit 154) The limit determination unit 154A of the allowable power limiting unit 154 determines whether it is necessary to limit the allowable power (calculated post-charge allowable power, calculated post-discharge allowable power) calculated by the allowable power calculation unit 153. When the limit determination unit 154A determines the necessity of limiting the allowable power, the limit execution unit 154B receives this and limits the calculated post-allowable power, and notifies the vehicle control unit 200 of the limited allowable power. Thereby, with respect to not only the abnormal operation state of the battery but also the tendency of the abnormal operation state of the battery, the vehicle control unit 200 improves the operation state of the battery by suppressing the drive of the motor generator 410.

[0045] Fig. 5 is for explaining the operation of the allowable power limiting unit 154 and is a characteristic diagram (graph) explaining the relationship between the limit rate of the allowable power and the values of the parameters. The limit determination unit 154A determines whether it is necessary to limit the allowable power by comparing the values of a plurality of types of operation parameters of the battery, for example, temperature, current, voltage, and SOC, with the specified threshold values, and makes a determination based on the comparison results. The limit execution unit 154B determines that it is necessary to limit the allowable power when the value of at least one parameter does not fall within the threshold value. On the other hand, when the values of all parameters fall within the threshold value, the limit determination unit 154A outputs the calculated post-allowable power to the vehicle control unit 200 as it is without determining the limit of the allowable power.

[0046] The thresholds include Vlimit (the first threshold), and Vth1 and Vth2, which are set so as not to exceed Vlimit (Vlimit > Vth2 > Vth1), as well as auxiliary thresholds (the second threshold). Vlimit is a threshold that assumes the battery has entered an abnormal operating state, and Vth1 is a threshold that assumes the battery is showing a tendency towards an abnormal operating state. When the parameter value reaches Vlimit, the limit determination unit 154A determines that the battery's operating state is an abnormal operating state such as high temperature or overvoltage, and that it is necessary to rapidly suppress the battery's operating state, and notifies the limit execution unit 154B of this. Upon receiving this notification, the limit execution unit 154B limits the calculated allowable power to the maximum (limit rate 100%).

[0047] On the other hand, when the parameter value becomes Vth1, which is smaller than Vlimit, the limit determination unit 154A determines that the battery's operating state is not in an abnormal operating state but is showing a tendency toward it, and determines that it is preferable to suppress the battery's operating state earlier, and notifies the limit execution unit 154B. Upon receiving this notification, the limit execution unit 154B relaxively limits the calculated allowable power between the parameter values ​​Vth1 and Vth1 (0% < limit rate < 100%).

[0048] As shown in Figure 5, the limiting rate does not suddenly become 100% when the parameter value reaches Vth1, but rather increases proportionally and gradually between Vth1 and Vth2 in line with the increase in the parameter value. This prevents situations where the vehicle's drive is suddenly restricted. Furthermore, by having the vehicle control unit 200 perform a gradual suppression operation of the vehicle in accordance with the gradual increase in the limiting rate, parameters such as the battery temperature decrease improve, and a situation can be reproduced where the calculated allowable current is not limited. In addition, the allowable power limiting unit 154 sets the limiting rate to 100% at Vth2, when the limiting input is smaller than Vlimit, thus protecting the battery from situations where a fault becomes fixed.

[0049] Alternatively, the limit rate may be gradually increased between Vth1 and Vlimit without setting Vth2. Furthermore, instead of setting the limit rate to 100% when the parameter value is Vth2 or higher, the rate of change of the limit rate may be varied between Vth1 and Vth2, and between Vth2 and Vlimit.

[0050] Figure 6, in contrast to Figure 5, is a graph illustrating how the limiting rate is relaxed from 100% to 0% as the parameter value decreases (Vlimit > Vth2 > Vth1). Vlimit is the upper limit of the threshold for the limiting input. Below Vlimit, the limiting rate is gradually reduced from 100% to 0% from Vth2 to Vth1.

[0051] Next, we will explain the application of the limiting factor to the calculated allowable power. Please assume that multiple limiting factors (Dchg1, Dchg2, Dchg3) are set for multiple limiting inputs. The number of limiting factors is not limited. Dchg1, Dchg2, and Dchg3 each take voltage, temperature, current, or SOC as the limiting input and represent the limiting factors explained in Figure 5 or Figure 6. Dchg1, Dchg2, and Dchg3 can take values ​​between 100% and 0%.

[0052] The Dchg shown below is a determined limit rate used by the limit execution unit 154B. Dchg is the largest value among Dchg1, Dchg2, and Dchg3, as shown in equation (10).

[0053] The charge-tolerance power Wchg is calculated by multiplying the calculated charge-tolerance power Wchg_raw by the limiting factor Dchg, as shown in equation (11).

[0054] The reason why the limiting factor Dchg is set to the maximum limiting factor is that, from the perspective of protecting the battery, it is desirable to limit the calculated allowable power to the strictest limiting factor when abnormal values ​​occur in multiple parameters such as voltage, current, temperature, and SOC.

[0055] Next, we will explain how the limiting rate is reflected in the discharge allowable power. The method by which the limiting execution unit 154B limits the calculated discharge allowable power based on multiple limiting rates will be explained below. We will assume that there are three limiting rates Ddis1, Ddis2, and Ddis3. The number of limiting rates is not limited. Ddis1, Ddis2, and Ddis3 are limiting rates calculated using the limiting rate calculation method explained in Figure 5, with parameters indicating the battery state such as voltage, temperature, and SOC as limiting inputs. Ddis1, Ddis2, and Ddis3 take values ​​between 100% and 0%.

[0056] Ddis is a determined limit rate. Similar to equation (10), the maximum value among the limit rates Ddis1, Ddis2, and Ddis3 is selected for Ddis, as shown in equation (12).

[0057] The discharge allowable power Wdis is calculated by multiplying the calculated discharge allowable power Wdis_raw by the limiting factor Ddis, as shown in equation (13).

[0058] The permissible power limiting unit 154 reads multiple battery operation parameters (temperature, voltage, current, SOC) at predetermined intervals, and the limiting determination unit 154A compares each of the multiple parameters with a corresponding threshold value and outputs the result as a determination result to the notification unit 155. As described above, if the parameter value exceeds the threshold value, the notification unit 155 interprets that the battery operation state is abnormal or prone to abnormal operation, converts it into notification information required by the vehicle system, and notifies the vehicle control unit 200. If the parameter value is outside the threshold value, the notification unit 155 notifies the vehicle control unit 200 that the battery operation state is normal.

[0059] Furthermore, the allowable power limiting unit 154 outputs information regarding the limiting ratio to the notification unit 155 via the limiting execution unit 154B. This information includes all or any of the limiting ratios Dchg1, Dchg2, Dchg3 for charge allowable power and the limiting ratio Dchg which is directly multiplied by the calculated charge allowable power, and the limiting ratios Ddis1, Ddis2, Ddis3 for discharge power and the limiting ratio Ddis which is directly multiplied by the calculated discharge allowable power. The notification unit 155 converts the limiting ratio into notification information required by the vehicle system and notifies the vehicle control unit 200.

[0060] The notification information passed to the vehicle control unit 200 can be transmitted via communication methods such as CAN, LIN, or SPI, or via a dedicated communication line. When the vehicle control unit 200 receives information from the notification unit 155 regarding abnormal battery operation, it takes actions such as limiting the vehicle's maximum speed, limiting the vehicle's acceleration performance, forcing the use of eco mode for energy-saving operation, and displaying a warning. Since the limit rate values ​​of Dchg and Ddis become notification information, the vehicle control unit 200 can change the operation of power consumption according to the strength of the limit rate.

[0061] Although the battery control system 100 and the vehicle control unit (ECU) 200 have been described as being physically independent, they may be integrated. As previously stated, the limit on permissible power has been explained, but instead of permissible power, permissible current may be used to limit the operation of the battery. "Permissible electrical characteristics" is a technical term that encompasses both permissible power and permissible current, and refers to at least one of permissible power and permissible current. Permissible electrical characteristics may be rephrased as permissible electrical parameters.

[0062] As shown in Figure 7, the storage unit 180 may store information from the allowable power limiting unit 154 and notification information. Since the storage unit 180 has a history of this information, the notification unit 155 can use this history to calculate statistical values ​​and transmit them to the vehicle control unit 200. The notification unit 155 can determine the frequency and interval of abnormal battery operation and notify the vehicle control unit 200 of this. The notification unit 155 can also calculate statistical values ​​such as the mean and variance.

[0063] In this way, the vehicle control unit 200 can utilize historical information from past TRIPs, in addition to the current TRIP (TRIP: the period from IGN ON (vehicle startup start) to OFF (vehicle startup stop)) allowable power, limiting factor values, and operating status information. This enables the vehicle to implement driving suppression tailored to the vehicle while preventing the vehicle's operation from being suddenly restricted in the event of abnormal battery operation.

[0064] The present invention is not limited to the configurations described in the embodiments, but can be appropriately configured based on the content described in the claims. The above embodiments are examples for carrying out the present invention. When carrying out the present invention, only some of the configurations of the embodiments may be implemented. When carrying out the present invention, configurations not described in the embodiments may be added to the embodiments. When carrying out the present invention, some of the configurations of the embodiments may be replaced with configurations not described in the embodiments. Modules, means, and units may be configured by combining electronic circuits.

[0065] 100: Battery control system, 110: Battery pack, 111: Single cell, 112: Group of single cells, 112a, 112b: Group of single cells, 120: Measurement unit, 121: Single cell control unit, 121a, 121b: Single cell control unit, 130: Current detection unit, 140: Voltage detection unit, 150: BMS, 151: Battery state detection unit, 152: Allowable power processing unit, 153: Allowable power calculation unit, 154: Allowable power limiting unit, 155: Notification unit, 160: Signal communication unit, 170: Insulation element, 180: Memory unit, 200: Vehicle control unit, 300, 310: Relay, 400: Inverter, 410: Motor generator, 420: Motor / inverter control unit

Claims

1. A battery control system for controlling the charging and discharging of a battery, comprising: an allowable electrical characteristics calculation unit for calculating the allowable electrical characteristics of the battery; a determination unit for determining whether it is necessary to limit the calculated allowable electrical characteristics; a limitation execution unit for limiting the calculated allowable electrical characteristics based on the determination result of the determination unit and outputting the limited allowable electrical characteristics to a control unit of a driven object; and a notification unit for notifying the control unit of the operating state of the battery based on the determination result of the determination unit.

2. The battery control system according to claim 1, wherein the allowable electrical characteristics are at least one of allowable power and allowable current, and the allowable power is the discharge allowable power or the charge allowable power.

3. The battery control system according to claim 1 or 2, wherein the notification unit notifies the control unit of the driven object that the operating state of the battery is showing a tendency toward abnormal operation.

4. The battery control system according to any one of claims 1 to 3, wherein the determination unit compares the operating parameters of the battery with a threshold value and determines whether the restriction is necessary based on the comparison result.

5. The battery control system according to any one of claims 1 to 4, wherein the limiting execution unit determines a limiting rate for the calculated allowable electrical characteristics based on the values ​​of the battery's operating parameters and a threshold value, and limits the calculated allowable electrical characteristics based on the limiting rate.

6. A battery control system according to claim 4, wherein a first threshold and a second threshold are set as the thresholds, the second threshold is set to a value of the operating parameter that is smaller than the first threshold, the limiting execution unit limits the calculated allowable power by a limiting rate that gradually increases in accordance with the increase in the value of the operating parameter when the value of the operating parameter exceeds the second threshold before the first threshold, and limits the calculated allowable power by the maximum limiting rate when the value of the operating parameter exceeds the first threshold.

7. The battery control system according to claim 5, wherein the limiting execution unit calculates a limiting rate for each of a plurality of operating parameters and limits the allowable electrical characteristics calculated by the allowable electrical characteristics calculation unit based on the highest limiting rate among the calculated limiting rates.

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