Backup control device for vehicle and backup device for vehicle

Abstract

Provided are a backup control device for a vehicle and a backup device for a vehicle, which can more appropriately supply power to a plurality of loads when a backup operation using an electricity storage portion is performed. A backup control device for a vehicle (1) has a discharge circuit that performs discharge of an electricity storage portion (70) and a control portion (40) that controls the discharge circuit. The control portion (40) sets, as a cutoff threshold, either one of a superimposable voltage determined as a voltage condition of the electricity storage portion (70) when power is simultaneously supplied to a plurality of target loads and a supply completion voltage determined in correspondence with any one of the plurality of target loads, in an abnormal state. The control portion (40) cuts off or delays power supply to any one of the plurality of target loads to inhibit simultaneous operation of the plurality of target loads, in the abnormal state, on condition that a charging voltage of the electricity storage portion (70) reaches or is below the cutoff threshold.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a backup control device for vehicle use and a backup device for vehicle use. BACKGROUND

[0002] Patent Literature 1 discloses a power storage device that supplies electric power from a power storage section to a load when a voltage of a main power source decreases. A control circuit of the power storage device controls a charging circuit to charge the power storage section when the main power source is normal. Also, the control circuit causes a switch disposed between the power storage section and the load to be turned on to supply electric power to the load when the voltage of the main power source decreases (for example, at the time of engine start after idling stop ends). In addition, Patent Literature 1 describes that the power storage device can also be applied to a power source backup system at the time of main power source abnormality.

[0003] PRIOR ART DOCUMENTS

[0004] Patent Literature 1: Japanese Patent Application Publication No. 2009-296808 SUMMARY

[0005] PROBLEMS TO BE SOLVED BY THE INVENTION

[0006] A backup device for vehicle use performs a backup operation of supplying electric power to a plurality of loads using a power storage section different from a main power source at the time of failure of the main power source, but in a case where the plurality of loads operate simultaneously, a problem caused by the simultaneous operation can occur. For example, in a case where a stored energy of the power storage section decreases below an energy required for the simultaneous operation but the plurality of loads still operate simultaneously, a situation where electric power is not appropriately supplied to the loads can occur.

[0007] The present disclosure provides a technology by which electric power can be more appropriately supplied to a plurality of loads at the time of performing a backup operation using a power storage section.

[0008] SOLUTION TO THE PROBLEM

[0009] A backup control device for vehicle use according to one embodiment of the present disclosure is used for a power source system for vehicle use that includes a power source section and a power storage section, and performs a backup operation of supplying electric power to at least a plurality of target loads based on electric power from the power storage section in an abnormal state where a voltage of a conductive path through which electric power is supplied from the power source section is less than a threshold value,

[0010] The backup control device for vehicle use includes a discharge circuit that discharges the power storage section, and a control section that controls the discharge circuit,

[0011] The control section sets, as a cutoff threshold value, either one of a superimposable voltage determined as a voltage condition of the power storage section in a case where electric power is simultaneously supplied to the plurality of target loads and a supply completion voltage determined in correspondence with any one of the plurality of target loads, in the abnormal state.

[0012] The control section cuts off or delays the power supply to any of the plurality of target loads to inhibit the simultaneous operation of the plurality of target loads as a condition that the charge voltage of the power storage section reaches below the cutoff threshold in the abnormal state.

[0013] Effects of Invention

[0014] The technology related to the present disclosure can more appropriately supply power to a plurality of loads when performing a backup operation using a power storage section. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is a block diagram that schematically illustrates a vehicle-mounted power supply system including a vehicle-mounted backup control device of a first embodiment.

[0016] Figure 2 is a flowchart illustrating a flow of control performed in the vehicle-mounted backup control device of the first embodiment. DETAILED DESCRIPTION

[0017] Hereinafter, an embodiment of the present disclosure will be exemplified. In addition, the features of the following exemplified [1] to [6] can be arbitrarily combined within a range not conflicting.

[0018] [1] A vehicle-mounted backup control device for a vehicle-mounted power supply system that includes a power supply section and a power storage section, the vehicle-mounted backup control device performing a backup operation of supplying power based on power from the power storage section to at least a plurality of target loads in an abnormal state in which a voltage of a conductive path through which power is supplied from the power supply section is less than a threshold value,

[0019] The vehicle-mounted backup control device includes a discharge circuit that performs discharge of the power storage section, and a control section that controls the discharge circuit,

[0020] The control section sets, as a cutoff threshold, either one of a superimposable voltage determined as a voltage condition of the power storage section in a case where power is simultaneously supplied to the plurality of target loads, and a supply completion voltage determined in correspondence with any of the plurality of target loads in the abnormal state,

[0021] The control section cuts off or delays the power supply to any of the plurality of target loads to inhibit the simultaneous operation of the plurality of target loads as a condition that the charge voltage of the power storage section reaches below the cutoff threshold in the abnormal state.

[0022] The backup control device for vehicle of the above-mentioned [1] can perform backup operation using the power storage section in an abnormal state where power supply from the power supply section is interrupted, and can supply power to the plurality of loads more appropriately while performing the backup operation. In the backup control device, it is possible to make it difficult to cause an adverse situation caused by simultaneous operation of the plurality of target loads in a state where the charging voltage is relatively low. Further, the backup control device can set the cutoff threshold value with emphasis on either the superimposable voltage or the supply completion voltage.

[0023] [2] The backup control device for vehicle of the above-mentioned [1] has the following feature. The plurality of target loads include a first target load and a second target load. The control section cuts off or delays power supply to the second target load when the first target load is not in the operation completion state and a condition for performing operation of the first target load is satisfied, in a case where the charging voltage of the power storage section is greater than the supply completion voltage determined in correspondence with the second target load and is equal to or lower than the superimposable voltage.

[0024] The backup control device for vehicle of the above-mentioned [2] can give priority to operation of the first target load in a case where the charging voltage of the power storage section is greater than the supply completion voltage determined in correspondence with the second target load, but is equal to or lower than the superimposable voltage. Therefore, the backup control device can make it difficult to cause a problem of insufficient power supply to the first target load caused by simultaneous operation of the first target load and the second target load in a case where the charging voltage of the power storage section is equal to or lower than the superimposable voltage.

[0025] [3] The backup control device for vehicle of the above-mentioned [1] or [2] has the following feature. The control section calculates the supply completion voltage of the target load on the basis of required energy determined in accordance with consumed power of the target load and a predetermined number of operations, output power from the discharging circuit, electrostatic capacitance of the power storage section, and the charging voltage of the power storage section at the time when the abnormal state occurs.

[0026] The backup control device for vehicle of the above-mentioned [3] can reflect consumed power of the target load and a predetermined number of operations, and appropriately set the supply completion voltage of the target load by adding output voltage of the discharging circuit, electrostatic capacitance of the power storage section, and the charging voltage of the power storage section at the time when the abnormal state occurs.

[0027] [4] The backup control device for vehicle of any one of the above-mentioned [1] to [3] has the following feature. The control section sets the superimposable voltage on the basis of an added value obtained by adding a predetermined lower limit voltage, a voltage drop amount in the power storage section expected in a case where the plurality of target loads simultaneously operate for a predetermined time, and a voltage drop in the power storage section in a case where the plurality of target loads simultaneously operate.

[0028] In the backup control device for vehicle use according to the above (4), it can be said that if the charge voltage of the power storage section exceeds the above-mentioned added value, even if a plurality of target loads act simultaneously for a predetermined time, the charge voltage of the power storage section is unlikely to reach the lower limit voltage. Therefore, if the stackable voltage is set based on such an added value, it is possible to make it unlikely that a plurality of target loads act simultaneously and the charge voltage of the power storage section becomes lower than the lower limit voltage.

[0029] (5) The backup control device for vehicle use according to the above (4) has the following feature. There is a temperature detection section that detects the temperature of the power storage section. The lower the temperature of the power storage section, the higher the lower limit voltage determined by the control section.

[0030] The backup control device for vehicle use according to the above (5) can reflect the actually detected temperature of the power storage section, and the lower the temperature of the power storage section, the higher the lower limit voltage determined. That is, the backup control device can set the stackable voltage higher the lower the actually detected temperature of the power storage section.

[0031] (6) A backup device for vehicle use has: the backup control device for vehicle use according to any one of (1) to (5); and the power storage section.

[0032] The backup device for vehicle use according to the above (6) has the same effect as the backup control device according to (1).

[0033] <First Embodiment>

[0034] <Structure of the power supply system for vehicle use>

[0035] Figure 1 The power supply system for vehicle use 100 illustrated in FIG. 1 has: a power supply section 90, a first load 91, a second load 92, a third load 93, a power storage section 70, and a backup control device for vehicle use 1. The backup control device for vehicle use 1 is also referred to as a backup control device 1. The power storage section 70 and the backup control device 1 constitute a backup device for vehicle use 2. The backup device for vehicle use 2 is also referred to as a backup device 2.

[0036] The power supply section 90 functions as a main power supply that continuously supplies electric power in a case where a vehicle in which the power supply system for vehicle use 100 is mounted is started. The power supply section 90 is a direct-current power supply that generates a direct-current voltage. The power supply section 90 is constituted by, for example, a storage battery such as a lead storage battery. A terminal on the high-potential side of the power supply section 90 is electrically connected to a power line 80, and a terminal on the low-potential side of the power supply section 90 is electrically connected to the ground. The power supply section 90 applies a predetermined voltage to the power line 80. In this specification, the voltage refers to a voltage with respect to the ground, unless otherwise specified.

[0037] The power supply section 90 is electrically connected to the first load 91, the second load 92, and the third load 93 via the power path 80. Electric power from the power supply section 90 is supplied to the first load 91, the second load 92, and the third load 93 via the power path 80. In Figure 1 In the example, the power path 80 has a conductive path, i.e., a power path 81A, directly connected to the power supply section 90, a power path 81B connected to the first load 91, a conductive path, i.e., a power path 81C, connected to the second load 92, and a conductive path, i.e., a power path 81D, connected to the third load 93. The power paths 81A, 81B, 81C, and 81D are electrically connected to each other. In a state in which electric power is supplied from the power supply section 90 to the first load 91, the second load 92, and the third load 93, the power paths 81A, 81B, 81C, and 81D are at the same potential. A relay, a fuse, and the like, which are not shown, are provided in the power path 80, and these elements have a function of cutting off conduction of the power path 80.

[0038] The first load 91, the second load 92, and the third load 93 are vehicle-mounted electrical devices. The first load 91, the second load 92, and the third load 93 are loads for which electric power supply is expected in an abnormal state (a failure state) in which electric power supply from the power supply section 90 is stopped. The first load 91, the second load 92, and the third load 93 may, for example, be actuators such as electric motors. Alternatively, they may be an ECU, an actuator in an electric parking brake system, an ECU, an actuator in a shift-by-wire control system, or the like. Alternatively, they may be vehicle-mounted electrical devices other than these.

[0039] In this specification, the first load 91 is also referred to as a load 91 or a first target load 91. The second load 92 is also referred to as a load 92 or a second target load 92. The third load 93 is also referred to as a load 93. The first load 91 and the second load 92 correspond to an example of a plurality of target loads.

[0040] The backup device 2 is a device that can supply electric power based on electric power of the power storage section 70 to the first load 91, the second load 92, and the third load 93 at least in an abnormal state in which electric power supply from the power supply section 90 is interrupted. The backup control device 1 is a device that controls such a backup operation.

[0041] The power storage section 70 functions as an auxiliary power supply. The power storage section 70 is a direct-current power supply that outputs a direct-current voltage, and is, for example, a double-layer capacitor. The power storage section 70 is electrically connected to the charge / discharge section 42 via a conductive path 26, and performs charging and discharging via the charge / discharge section 42. A charging voltage (an output voltage) of the power storage section 70 is a voltage applied to the conductive path 26. A terminal on a high-potential side of the power storage section 70 is electrically connected to the conductive path 26, and is at the same potential as the conductive path 26. A terminal on a low-potential side of the power storage section 70 is electrically connected to the ground, and is at the same potential as the ground.

[0042] In the backup device 2, the charging voltage (output voltage) of the power storage portion 70 is kept below the standby voltage in a stopped state in which the start switch of the vehicle on which the vehicle-mounted power supply system 100 is mounted becomes the off state. Also, the backup device 2 performs charging so that the charging voltage of the power storage portion 70 reaches a target voltage that is greater than the standby voltage, in accordance with the start switch of the vehicle switching to the on state. When the start switch of the vehicle is in the on state, the charging voltage of the power storage portion 70 is maintained at the target voltage in the case where a failure state does not occur. In the case where the start switch of the vehicle switches from the on state to the off state, the backup device 2 discharges the power storage portion 70 until the charging voltage of the power storage portion 70 becomes below the standby voltage.

[0043] The backup control device 1 has a control portion 40, a charge-discharge portion 42, switches 11, 12, 13, 14, 15, voltage detection portions 31, 32, conduction paths 21, 22, 23, 24, 25, 26, 27, 28, 29A, 29B, 29C, and the like.

[0044] The control portion 40 is an information processing device having an information processing function, an arithmetic function, a control function, and the like. The control portion 40 is configured with, for example, a microcomputer as a main body, and has an arithmetic device such as a CPU (Central Processing Unit), a memory such as a ROM (Read Only Memory) or a RAM (Random Access Memory), an A / D converter, and the like. The control portion 40 has a function of controlling the charge-discharge portion 42 (discharge circuit).

[0045] The charge-discharge portion 42 corresponds to an example of a discharge circuit. The charge-discharge portion 42 is configured as a voltage conversion circuit such as a DCDC converter. The charge-discharge portion 42 is disposed between the conduction path 26 and the conduction path 27. The charge-discharge portion 42 performs a charging operation and a discharging operation with respect to the power storage portion 70. The charge-discharge portion 42 performs a voltage conversion operation of boosting or stepping down a voltage applied to the conduction path 27 and applying the voltage to the conduction path 26 as the charging operation. The charging operation of the charge-discharge portion 42 is controlled by the control portion 40. The control portion 40 causes the switches 14, 15 to become the on state in a case where the charge-discharge portion 42 is caused to perform the above-described charging operation. The charge-discharge portion 42 performs a voltage conversion operation of boosting or stepping down a voltage applied to the conduction path 26 and applying the voltage to the conduction path 27 as the discharging operation. The discharging operation of the charge-discharge portion 42 is controlled by the control portion 40. The control portion 40 causes, for example, the switches 14, 15 to become the off state and causes one or more of the switches 11, 12, 13 to become the on state in a case where the charge-discharge portion 42 is caused to perform the above-described discharging operation.

[0046] The voltage detection sections 31, 32 are configured as, for example, voltage detection circuits. The voltage detection section 31 detects the voltage of the conductive path 24. The conductive path 24 is a conductive path that is electrically connected to the power path 80 and is at the same potential as the power path 80. Therefore, the voltage detection section 31 can detect the voltage of the power path 80. The voltage detection section 32 detects the voltage of the conductive path 26. The conductive path 26 is a conductive path that is electrically connected to the terminal on the high potential side of the power storage section 70 and is at the same potential as the terminal on the high potential side of the power storage section 70. Therefore, the voltage detection section 32 can detect the charging voltage (output voltage) of the power storage section 70. The charging voltage of the power storage section 70 is the voltage of the terminal on the high potential side of the power storage section 70 with respect to the ground.

[0047] The conductive path 25 is a conductive path that is connected to the conductive path 24 via the switch 14. The conductive path 24 and the conductive path 25 are in conduction with each other and are at the same potential when the switch 14 is in the on state. The conductive path 27 is a conductive path that is connected to the conductive path 25 via the switch 15. The conductive path 27 is a conductive path that is electrically connected to one end side of the charge / discharge section 42. The conductive path 25 and the conductive path 27 are in conduction with each other and are at the same potential when the switch 15 is in the on state. The conductive path 26 is a conductive path that is electrically connected to the other end side of the charge / discharge section 42. The conductive path 28 is a conductive path that is electrically connected to the conductive path 27 at one end and is electrically connected to the conductive paths 29A, 29B, 29C at the other end. The conductive paths 27, 28, 29A, 29B, 29C are at the same potential. One end of the conductive path 29A is electrically connected to the conductive path 28, and the other end is electrically connected to the anode of the diode 37. The cathode of the diode 37 is electrically connected to the conductive path 25. The conductive path 21 is a conductive path between the switch 11 and the first load 91. The conductive path 25 and the conductive path 21 are at the same potential when the switch 11 is in the on state. One end of the conductive path 29B is electrically connected to the conductive path 28, and the other end is electrically connected to the switch 12. The conductive path 29B and the conductive path 22 are at the same potential when the switch 12 is in the on state. One end of the conductive path 29C is electrically connected to the conductive path 28, and the other end is electrically connected to the switch 13. The conductive path 29C and the conductive path 23 are at the same potential when the switch 13 is in the on state.

[0048] 〔Action of the backup control device〕

[0049] Figure 2 An example of the backup control performed by the control section 40 is shown. The control section 40 starts the backup control of Figure 2 when predetermined start conditions are satisfied. The backup control of Figure 2The condition for starting the backup control can be, for example, a case where the start switch of the vehicle on which the vehicle-mounted power supply system 100 is mounted is switched from the off state to the on state, or another condition. In the representative example described below, in a case where the start switch of the vehicle is switched from the off state to the on state, a start signal indicating that the start switch is switched to the on state is supplied to the control section 40 from an external device (for example, an external ECU (Electronic Control Unit)). The control section 40 starts the backup control of the power supply section 90 in a case where such a start signal is received. Figure 2

[0050] The control section 40 starts the backup control of the power supply section 90 in a case where such a start signal is received. Figure 2 The control section 40 determines whether or not the power supply section 90 (main power supply) is in the failure state in step S11. The control section 40 determines whether or not the voltage of the conduction path 24 is less than a threshold value on the basis of the voltage detected by the voltage detection section 31. The threshold value is a value that is substantially smaller than the output voltage applied to the power path 80 at normal times of the power supply section 90, and is a value that is larger than 0. The control section 40 advances the processing to step S12 in a case where the voltage of the conduction path 24 is determined to be less than the threshold value in step S11 (in a case where the answer is YES in step S11). In the present representative example, a case where the voltage of the conduction path 24 is less than the threshold value, that is, a case where the voltage of the power path 80 is less than the threshold value corresponds to an example of the abnormal state. The control section 40 ends the control in a case where the voltage of the conduction path 24 is determined to be equal to or more than the threshold value in step S11 (in a case where the answer is NO in step S11). The control section 40 starts the control in step S12 immediately after ending the control in step S11 in a case where the answer is NO in step S11. Thus, in a case where the power supply section 90 is not in the above-described abnormal state, the backup control in step S12 and the determination processing in step S11 are repeatedly executed at a short time interval. Figure 2 Figure 2 Figure 2 Figure 2

[0051] ​​​​​For example, in an abnormal state where the power supply from the power supply portion 90 to the conductive circuit 24 and the power supply to the power paths 81B, 81C, 81D are interrupted due to a ground fault or a disconnection in the power path 80, the voltage of the conductive circuit 24 is about 0 V. In such a case, in the backup control device 1, the control portion 40 causes the charge-discharge portion 42 to perform a discharging operation of supplying power to the conductive circuit 27 and performs the process after the step S12 to perform a backup operation of supplying power to the plurality of loads 91, 92, 93 based on the power from the power storage portion 70. In addition, hereinafter, an example in which the loads 91, 92 are target loads and power is supplied to the loads 91, 92 in a case where the main power supply fails will be described. In addition, in a case where the backup operation of supplying power to the plurality of loads 91, 92 is performed, the switches 11, 12 can be brought to the on state at the timing of the step S12, or the switches 11, 12 can be brought to the on state slightly earlier or slightly later than the timing of the step S12. The charge-discharge portion 42 can bring the switches 12, 13, 15 to the off state and continuously perform the operation of applying the predetermined voltage to the conductive circuit 27 in a normal time (a state where the main power supply does not fail) other than the charging state of the power storage portion 70, or can start the operation of applying the predetermined voltage to the conductive circuit 27 after "Yes" in the step S11.

[0052] In a case where the control portion 40 determines that the voltage of the conductive circuit 24 is less than the threshold value in the step S11 (in a case where "Yes" in the step S11), the control portion 40 records the temperature Tc of the power storage portion 70 and the charging voltage Vb of the power storage portion 70 in the step S12. The temperature Tc of the power storage portion 70 and the charging voltage Vb of the power storage portion 70 at the timing of the step S12 are stored in, for example, a storage portion not shown. In Figure 1 The backup device 2 shown is provided with a temperature detection portion 35 that detects the temperature Tc of the power storage portion 70 (for example, the surface temperature or the internal temperature of the power storage portion 70). The control portion 40 acquires information of the temperature detected by the temperature detection portion 35 at the timing of the step S12 and stores the temperature Tc of the power storage portion 70 in the storage portion.

[0053] The control portion 40 calculates the cutoff threshold value related to the second target load 92 in the step S13 after the step S12. The control portion 40 sets either one of the superimposable voltage Ve and the supply completion voltage Vg as the cutoff threshold value in an abnormal state where the process after the step S13 is performed. The superimposable voltage Ve is a voltage determined as a voltage condition of the power storage portion 70 in a case where power is simultaneously supplied to the plurality of target loads (the first target load 91, the second target load 92). The supply completion voltage Vg is a voltage determined in correspondence with the second target load 92.

[0054] The control section 40 sets the supply completion voltage Vg of the second target load 92 in the following manner. The control section 40 first calculates the required energy E. In calculating the required energy, the required energy of the loads 91, 92, 93 is determined in the following manner. The required energy El of the load 91 is determined by the formula X1 x N1 from the consumption power Xl of one operation of the load 91 and the predetermined number of operations Nl. The required energy E2 of the load 92 is determined by the formula X2 x N2 from the consumption power X2 of one operation of the load 92 and the predetermined number of operations N2. The required energy E3 of the load 93 is determined by the formula X3 x N3 from the consumption power X3 of one operation of the load 93 and the predetermined number of operations N3. In addition, the units of E, El, E2, E3 are, for example, mAh. The units of Xl, X2, X3 are, for example, mAh.

[0055] In the case where the control section 40 calculates the supply completion voltage Vg of the second target load 92 at the timing of step S13, in the case where the load 91 and the load 93 do not operate at the timing of step S13, the control section 40 calculates the required energy E based on the required energy E2 of the load 92 by the formula E = E2 + Ic x (Tm - Tr). Ic is the consumption current of the backup device 2 itself per unit time, and is, for example, a value determined in advance. The unit of Ic is, for example, mA / s. Tm is the maximum operation time determined in advance as the maximum time for operating the backup device 2. Tr is the elapsed operation time from when the entry to "Yes" in step Sll (when it is determined that the failure of the power supply section 90 has occurred) to the timing of calculating the required energy E in step S13. The units of Tm, Tr are, for example, s.

[0056] In the case where the control section 40 calculates the supply completion voltage Vg of the second target load 92 at the timing of step S13, in the case where the load 91 does not operate and the load 93 completes operation at the timing of step S13, the control section 40 calculates the required energy E based on the required energy E2 of the load 92 and the required energy E3 of the load 93 by the formula E = E2 + E3 + Ic x (Tm - Tr).

[0057] In the case where the control section 40 calculates the supply completion voltage Vg of the second target load 92 at the timing of step S13, in the case where the load 91 completes operation and the load 93 does not operate at the timing of step S13, the control section 40 calculates the required energy E based on the required energy El of the load 91 and the required energy E2 of the load 92 by the formula E = E2 + El + Ic x (Tm - Tr).

[0058] The control section 40 calculates the required energy E based on the required energy El of the load 91, the required energy E2 of the load 92, and the required energy E3 of the load 93 by the equation E = El + E2 + E3 + Ic x (Tm - Tr) in the case where the supply completion voltage Vg of the second target load 92 is calculated in step S13 and the loads 91, 93 complete the operation at the timing of step S13.

[0059] The control section 40 calculates Z (J) based on the equation E (mAh) x Vc (V) = Z (J) in the case where the required energy E is calculated in step S13. Vc (V) is the output voltage applied to the conductive path 27 by the charge and discharge section 42. Also, the estimated voltage Va after discharge is calculated based on the equation Z (J) = C x A x B x (Vb 2 - Va 2 ) / 2. This Va is the supply completion voltage Vg determined in correspondence with the second target load 92. The value of the above-mentioned A is a deterioration state coefficient. The deterioration state coefficient (deterioration coefficient) can be calculated and set in a known method, or can be a predetermined value. The value of the above-mentioned B is the discharge efficiency of the charge and discharge section 42. The discharge efficiency can be calculated and set in a known method, or can be a predetermined value. The value of the above-mentioned C is the static capacitance of the power storage section 70. The control section 40 can detect the static capacitance C in a known method. The control section 40 can detect the static capacitance C at a predetermined time (for example, each time the charge and discharge section 42 operates), and use the most recently detected static capacitance C in step S13.

[0060] Thus, the control section 40 calculates the supply completion voltage Vg of the second target load 92 from the required energy E based on the required energy E2, the output power from the charge and discharge section 42 (discharge circuit), the static capacitance C of the power storage section 70, and the charge voltage Vb of the power storage section 70 when an abnormal state occurs.

[0061] The control section 40 calculates the superimposable voltage Ve as follows. The control section 40 sets the superimposable voltage Ve based on the sum (Vx + Vy + Vz) of a predetermined lower limit voltage Vx, a voltage drop amount Vy in the power storage section 70 expected in the case where the plurality of target loads (the first target load 91 and the second target load 92) simultaneously operate for a predetermined time, and a voltage drop Vz in the power storage section 70 in the case where the plurality of target loads (the first target load 91 and the second target load 92) simultaneously operate. In the following example, Ve = Vx + Vy + Vz is set. However, the superimposable voltage Ve can be set by adding a correction value or multiplying a coefficient to the sum, not limited to this example.

[0062] The lower limit voltage Vx is a lower limit value of the input-side voltage (voltage of the conduction path 26) required for the charge / discharge section 42 to supply a predetermined power (predetermined output voltage and predetermined output current) determined in advance. The Vx can be a fixed value determined in advance, or can be determined based on the temperature Tc of the power storage section 70. In the case where the lower limit voltage Vx is determined based on the temperature Tc, the control section 40 can determine the lower limit voltage Vx corresponding to the temperature Tc based on the temperature Tc of the power storage section 70 detected by the temperature detection section 35, with reference to a predetermined operation formula or a predetermined table in which the lower limit voltage Vx is determined to be higher as the temperature Tc of the power storage section 70 is lower.

[0063] The voltage drop amount Vy can be determined by Vy = ((a + β) x Ty) / (C x Dt), for example. a is the load current of the first load 91, and β is the load current of the second load 92. a and β can be determined as fixed values of the current values assumed in advance, for example. Ty is the generation time of the surge current. Ty can be determined as a fixed value of the time assumed in advance. Dt is a temperature coefficient. The control section 40 determines the temperature coefficient Dt corresponding to the temperature Tc based on a predetermined operation formula or table. In the present example, Vy is determined by the above operation formula according to the temperature Tc, but can be set as a fixed value.

[0064] Vz can be calculated by Vz = (a + β) x (Rc x Ft), for example. Rc is the internal resistance of the power storage section 70. The control section 40 can detect the internal resistance Rc in a known method. The control section 40 can detect the internal resistance Rc at a predetermined timing (for example, every time the charge / discharge section 42 operates), and use the most recently detected internal resistance Rc in step S13. Ft is a temperature coefficient. The control section 40 determines the temperature coefficient Ft corresponding to the temperature Tc based on a predetermined operation formula or table.

[0065] After the control section 40 calculates the supply completion voltage Vg and the superimposable voltage Ve in step S13, it determines whether Vg < Ve. If Vg < Ve, Vg is set as the cutoff threshold. If Vg ≥ Ve, Ve is set as the cutoff threshold.

[0066] The control section 40 determines whether the charge voltage (output voltage) of the power storage section 70 is below the cutoff threshold in step S14 after step S13. The control section 40 cuts off the power supply to the second target load 92 in step S15 when it determines that the charge voltage of the power storage section 70 is below the cutoff threshold in step S14. The control section 40 brings the switch 12 to the open state when it cuts off the power supply to the second target load 92 in step S15. In this case, the control section 40 causes the charge / discharge section 42 to continuously perform the operation of applying the predetermined voltage to the conductor circuit 27, and supplies power to the first target load 91 if the switch 11 is in the on state, and cuts off the power supply to the first target load 91 if the switch 11 is in the off state. In this case, the control section 40 can control the on and off of the switch 11, for example, in accordance with an instruction from an external device.

[0067] The control section 40 determines whether the charge voltage of the power storage section 70 is below the cutoff threshold in step S14 after step S13. The control section 40 cuts off the power supply to the second target load 92 in step S15 when it determines that the charge voltage of the power storage section 70 is below the cutoff threshold in step S14. The control section 40 brings the switch 12 to the open state when it cuts off the power supply to the second target load 92 in step S15. In this case, the control section 40 causes the charge / discharge section 42 to continuously perform the operation of applying the predetermined voltage to the conductor circuit 27, and supplies power to the first target load 91 if the switch 11 is in the on state, and cuts off the power supply to the first target load 91 if the switch 11 is in the off state. In this case, the control section 40 can control the on and off of the switch 11, for example, in accordance with an instruction from an external device.

[0068] The control section 40 determines whether the charge voltage (output voltage) of the electric storage section 70 exceeds the notification reference voltage Vd in step S19. The control section 40 determines that the charge voltage (output voltage) of the electric storage section 70 does not exceed the notification reference voltage Vd in step S19, cuts off the electric power supply to the second target load 92 in step S20, and then performs the process of notifying of the SOC drop of the electric storage section 70 in step S21.

[0069] The control section 40 performs other processes in step S22 after determining that the charge voltage (output voltage) of the electric storage section 70 exceeds the notification reference voltage Vd in step S19 or after step S21, and then returns the process to step S13.

[0070] As described above, the control section 40 cuts off or delays the electric power supply to any of the plurality of target loads (the first target load 91, the second target load 92) in the above abnormal state with the condition that the charge voltage of the electric storage section 70 reaches below the cutoff threshold value, and prohibits the simultaneous operation of the plurality of target loads. Also, the control section 40 cuts off the electric power supply to the second target load 92 when the first target load 91 is not in the operation completion state and the condition for performing the operation of the first target load 91 is satisfied, in the case where the charge voltage of the electric storage section 70 is greater than the supply completion voltage Vg determined in correspondence with the second target load 92 and is below the superimposable voltage Ve.

[0071] The following description relates to one example of the effect of the present configuration.

[0072] The backup control device 1 can perform the backup operation using the electric storage section 70 in the abnormal state where the electric power supply from the power supply section 90 is interrupted, and can more appropriately supply electric power to the plurality of loads 91, 92, 93 when the backup operation is performed. In this backup control device 1, it is possible to make it difficult to cause the adverse situation caused by the simultaneous operation of the plurality of target loads (the first target load 91, the second target load 92) in the state where the charge voltage of the electric storage section 70 is relatively low. Also, this backup control device 1 can set the cutoff threshold value with emphasis on either of the superimposable voltage and the supply completion voltage.

[0073] The backup control device 1 can give priority to the operation of the first target load 91 in the case where the charge voltage of the electric storage section 70 is below the superimposable voltage even if it is greater than the supply completion voltage determined in correspondence with the second target load 92. Therefore, this backup control device 1 can make it difficult to cause the problem of the insufficient electric power supply to the first target load 91 caused by the operation of both the first target load 91 and the second target load 92 in the case where the charge voltage of the electric storage section 70 is below the superimposable voltage.

[0074] The backup control device 1 can reflect the consumption power of the target load and the predetermined number of actions, and appropriately set the supply completion voltage of the target load in consideration of the output voltage of the charge / discharge section 42 (discharge circuit), the static capacitance of the power storage section 70, and the charge voltage of the power storage section 70 when the abnormal state occurs.

[0075] In the backup control device 1, it can be said that if the charge voltage of the power storage section 70 exceeds the above-mentioned added value, the charge voltage of the power storage section 70 is unlikely to reach the lower limit voltage even if the plurality of target loads act simultaneously for the predetermined time. Therefore, if the stackable voltage is set based on such an added value, it is unlikely that the plurality of target loads act simultaneously and the charge voltage of the power storage section becomes lower than the lower limit voltage.

[0076] The backup control device 1 can reflect the actually detected temperature of the power storage section 70, and the lower the temperature of the power storage section 70, the higher the lower limit voltage is determined to be. That is, the backup control device 1 can set the stackable voltage to be higher the lower the actually detected temperature of the power storage section 70.

[0077] <Other Embodiments>

[0078] The present disclosure is not limited to the embodiments described above and illustrated in the drawings. For example, the features of the above-mentioned or hereinafter described embodiments can be combined in all possible combinations as long as they are not contradictory. In addition, any of the features of the above-mentioned or hereinafter described embodiments can be omitted as long as it is not explicitly stated as a necessary feature. Furthermore, the above-mentioned embodiments can be changed in the following manner.

[0079] In the above-mentioned embodiments, an example in which the simultaneous action of the plurality of target loads is prohibited by cutting off or delaying the power supply to any of the plurality of target loads with the condition that the charge voltage of the power storage section 70 reaches below the cutoff threshold in the abnormal state is described, but is not limited to the above-mentioned example. It can be that, in the case where the charge voltage of the power storage section 70 reaches below the cutoff threshold in the abnormal state, the power supply to any of the plurality of target loads is completely cut off, and the power supply to the cut-off target load is not performed at all in the backup action thereafter. Or, it can be that, in the case where the cutoff threshold is reached, the power supply to any of the plurality of target loads is temporarily delayed to prevent simultaneous supply, and is performed after the action of the other target load is completed.

[0080] In the above-mentioned first embodiment, the start switch of the vehicle is described, but the start switch can be an ignition switch. Or, in an electric vehicle or the like, it can be a power switch for instructing the EV system.

[0081] In the above-described first embodiment, the power supply section is a lead storage battery, but is not limited to a lead storage battery. The power supply section can also be another kind of battery such as a lithium ion storage battery, and can also be a power source such as an alternator, a converter, or the like.

[0082] In the above-described first embodiment, the power storage section is an electric double layer capacitor, but the power storage section is not limited to an electric double layer capacitor. The power storage section can also be another kind of power storage section such as a lithium ion capacitor, a lithium ion storage battery, or the like.

[0083] In the above-described first embodiment, the backup control device performs a backup operation in the case where the power supply from the power supply section is interrupted, but the backup control device can also perform a backup operation in a predetermined state where the power supply is not completely interrupted, in a manner of supplying power from the power storage section.

[0084] In the above-described first embodiment, an example of a method of determining the superimposable voltage is shown, but is not limited to this example. With respect to the superimposable voltage, a value corrected by a method in which the method shown in the first embodiment is changed in several ways, such as a method in which a superimposable voltage obtained by the method shown in the first embodiment is multiplied by a certain coefficient or is added to a correction value of a corresponding margin, can be set as the superimposable voltage, and a predetermined fixed value can also be set as the superimposable voltage. In the above-described first embodiment, an example of a method of determining the supply completion voltage corresponding to the second target load 92 is shown, but is not limited to this example. With respect to the supply completion voltage corresponding to the second target load 92, a value corrected by a method in which the method shown in the first embodiment is changed in several ways, such as a method in which a supply completion voltage obtained by the method shown in the first embodiment is multiplied by a certain coefficient or is added to a correction value of a corresponding margin, can be set as the supply completion voltage, and a predetermined fixed value corresponding to the second target load 92 can also be set as the supply completion voltage.

[0085] In addition, it should be understood that the embodiments disclosed herein are illustrative only and not restrictive of the scope of the application. The scope of the application is defined by the appended claims, and the scope of those claims will include all modifications that come within the meaning and range of equivalents of the claims.

[0086] BRIEF DESCRIPTION OF DRAWINGS

[0087] 1: backup control device

[0088] 2: backup device

[0089] 11: switch

[0090] 12: switch

[0091] 13: switch

[0092] 14: switch

[0093] 15: switch

[0094] 21: conductive path

[0095] 22: conductive path

[0096] 23: conductive path

[0097] 24: conductive path

[0098] 25: conductive path

[0099] 26: conductive path

[0100] 27: conductive path

[0101] 28: conductive path

[0102] 29A: conductive path

[0103] 29B: conductive path

[0104] 29C: conductive path

[0105] 31: voltage detection unit

[0106] 32: voltage detection unit

[0107] 35: temperature detection unit

[0108] 37: diode

[0109] 40: control unit

[0110] 42: charge and discharge unit

[0111] 70: power storage unit

[0112] 80: power line

[0113] 81A: power line

[0114] 81B: power line

[0115] 81C: power line

[0116] 81D: power line

[0117] 90: power supply unit

[0118] 91: first load (first target load)

[0119] 92: second load (second target load)

[0120] 93: third load

[0121] 100: vehicle-mounted power supply system

Claims

1. A backup control device for a vehicle, for a vehicle-mounted power supply system that includes a power supply unit and an electric storage unit, performs a backup operation of supplying electric power to at least a plurality of target loads based on electric power from the electric storage unit in an abnormal state in which a voltage of a conductive path from which electric power is supplied from the power supply unit is less than a threshold value, the backup control device for a vehicle has: a discharge circuit that performs discharge of the electric storage unit; and a control unit that controls the discharge circuit, the control unit sets either of a superimposable voltage and a supply completion voltage as a cutoff threshold value in the abnormal state, the superimposable voltage being a voltage determined as a voltage condition of the electric storage unit in a case in which electric power is simultaneously supplied to the plurality of target loads, the supply completion voltage being a voltage determined in correspondence with any one of the plurality of target loads, the control unit cuts off or delays supply of electric power to any one of the plurality of target loads to inhibit simultaneous operation of the plurality of target loads in the abnormal state, on a condition that a charge voltage of the electric storage unit reaches or is below the cutoff threshold value, the control unit calculates the supply completion voltage of the target load based on a required energy determined in accordance with a consumed electric power of the target load and a predetermined number of operations, an output electric power from the discharge circuit, an electrostatic capacitance of the electric storage unit, and the charge voltage of the electric storage unit at a time when the abnormal state occurs.

2. A backup control device for a vehicle, for a vehicle-mounted power supply system that includes a power supply unit and an electric storage unit, performs a backup operation of supplying electric power to at least a plurality of target loads based on electric power from the electric storage unit in an abnormal state in which a voltage of a conductive path from which electric power is supplied from the power supply unit is less than a threshold value, the backup control device for a vehicle has: a discharge circuit that performs discharge of the electric storage unit; and a control unit that controls the discharge circuit, the control unit sets either of a superimposable voltage and a supply completion voltage as a cutoff threshold value in the abnormal state, the superimposable voltage being a voltage determined as a voltage condition of the electric storage unit in a case in which electric power is simultaneously supplied to the plurality of target loads, the supply completion voltage being a voltage determined in correspondence with any one of the plurality of target loads, the control unit cuts off or delays supply of electric power to any one of the plurality of target loads to inhibit simultaneous operation of the plurality of target loads in the abnormal state, on a condition that a charge voltage of the electric storage unit reaches or is below the cutoff threshold value, the control unit sets the superimposable voltage based on an added value obtained by adding a predetermined lower limit voltage, a voltage drop amount in the electric storage unit expected in a case in which the plurality of target loads simultaneously operate for a predetermined time, and a voltage drop in the electric storage unit in a case in which the plurality of target loads simultaneously operate, the voltage drop amount is related to a generation time of an inrush current, and the voltage drop is related to an internal resistance of the electric storage unit.

3. The backup control device for a vehicle according to claim 1 or 2, in which The control section cuts off the supply of electric power to any of the plurality of object loads to inhibit the simultaneous operation of the plurality of object loads, in the abnormal state, on the condition that the charge voltage of the electric storage section reaches below the cutoff threshold value.

4. The backup control device for vehicle use according to claim 1 or 2, wherein The plurality of object loads include a first object load and a second object load, The control section cuts off or delays the supply of electric power to the second object load, in a case where the charge voltage of the electric storage section is greater than the supply completion voltage determined in correspondence with the second object load and is below the superimposable voltage, when the first object load is not in the operation completion state and the condition for performing the operation of the first object load is satisfied.

5. A backup device for vehicle use, comprising: The backup control device for vehicle use according to any one of claims 1 to 4; and The electric storage section.

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