Standby power supply device and method for controlling the standby power supply device

Abstract

To provide an auxiliary power supply device capable of monitoring a deterioration state of an electric double layer capacitor of a backup power supply.SOLUTION: An auxiliary power supply device includes: a power storage circuit provided with a first electric double layer capacitor and a second electric double layer capacitor that are connected in series to each other between a first node and a second node; a first switching element having a first terminal connected to the first node, and a second terminal; a first discharge resistance provided between the second terminal and a fourth node; a second discharge resistance provided between the fourth node and a ground; a second switching element having a third terminal connected to a third node between the first electric double layer capacitor and the second electric double layer capacitor, and a fourth terminal connected to the fourth node; and a measurement control unit. The measurement control unit executes the steps of: calculating a capacity value of the power storage circuit as first processing; and connecting the first switching element and connecting the second switching element as second processing.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a standby power supply device and a method for controlling a standby power supply device. [Background technology]

[0002] 2. Description of the Related Art A backup power supply is known that is provided in an automobile to supply electric energy in place of or to supplement the main power supply in the event of a failure or interruption of the main power supply (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6675874 Summary of the Invention [Problem to be solved by the invention]

[0004] Patent Document 1 discloses that a supercapacitor is used as a backup power source. When using an electric double layer capacitor such as a supercapacitor as a backup power source, it is necessary to monitor the deterioration state of the electric double layer capacitor.

[0005] The present disclosure provides a standby power supply device capable of monitoring the degradation state of an electric double layer capacitor of a backup power supply. [Means for solving the problem]

[0006] In one aspect of the present disclosure, there is provided an energy storage circuit having a first node connected to a power source and a second node grounded, the energy storage circuit including a first electric double layer capacitor and a second electric double layer capacitor connected in series between the first node and the second node, a first switch element having a first terminal connected to the first node and a second terminal and connecting or disconnecting the first terminal and the second terminal, a first discharge resistor provided between the second terminal and a fourth node, a second discharge resistor provided between the fourth node and ground, a third terminal connected to a third node between the first electric double layer capacitor and the second electric double layer capacitor, and a fourth terminal connected to the fourth node, the second switch element having a first discharge resistor provided between the second terminal and a fourth node, the third terminal connected to a third node between the first electric double layer capacitor and the second electric double layer capacitor, and a fourth terminal connected to the fourth node, the second switch element having a first discharge resistor provided between the second discharge resistor and a fourth node, the second switch element having a second discharge resistor provided between the second discharge resistor and ground, the third terminal connected to a third node between the first electric double layer capacitor and the second electric double layer capacitor, and a fourth terminal connected to the fourth node, the second switch element having a second discharge resistor provided between the second discharge resistor and ground, the third terminal connected to a third node between the first electric double layer capacitor and the second electric double layer capacitor, a step of connecting between the first terminal and the second terminal by the first switch element, a step of measuring a voltage of the first node to obtain a first voltage value, a step of determining whether the voltage of the first node is equal to or lower than a second voltage value that is lower than the first voltage value, a step of opening between the first terminal and the second terminal by the first switch element if the voltage of the first node is equal to or lower than the second voltage value, a step of calculating a time from when the first terminal and the second terminal are connected by the first switch element to when they are opened, and a step of calculating a capacitance value of the storage circuit based on the time, the first voltage value, and the second voltage value. Effect of the Invention

[0007] According to the standby power supply device of the present disclosure, the deterioration state of the electric double layer capacitor of the backup power supply can be monitored. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing an example of the configuration of a standby power supply device according to this embodiment. [Diagram 2] FIG. 2 is a diagram showing an example of the configuration of an equalization / discharge circuit of a standby power supply device according to this embodiment. [Diagram 3] FIG. 3 is an equivalent circuit diagram for measuring the capacitance value and the equivalent series resistance value of the power storage circuit in the standby power supply device according to this embodiment. [Figure 4] FIG. 4 is a flowchart for measuring the capacitance value of the power storage circuit in the standby power supply device according to this embodiment. [Diagram 5] FIG. 5 is a flowchart for measuring the equivalent series resistance of the power storage circuit in the standby power supply device according to this embodiment. [Figure 6] FIG. 6 is a flowchart for measuring the capacitance value and the equivalent series resistance value of the power storage circuit in the standby power supply device according to this embodiment. [Figure 7] FIG. 7 is a circuit diagram of a circuit that performs equalization processing and measures the capacitance value and equivalent series resistance value of the storage circuit in the standby power supply device according to this embodiment. [Figure 8] FIG. 8 is a flowchart showing the process of equalizing the storage circuit and measuring the capacitance and equivalent series resistance in the standby power supply device according to this embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, a backup power supply device according to an embodiment of the present disclosure will be described in detail with reference to the drawings.

[0010] <Backup Power Supply Unit 1> FIG. 1 is a diagram showing an example of the configuration of a standby power supply device 1 according to this embodiment. In recent years, in latch mechanisms, which are mechanical locking mechanisms for automobile doors, a system in which the locking portion of the latch is operated by a motor has been adopted as an electric latch system. It is essential that automobile doors can be released in emergencies such as accidents. For this reason, even if the battery power source is lost due to destruction in an accident, the electric latch system must be able to continue operating for a certain period of time. The standby power supply device 1 according to this embodiment is used as a backup power source for the electric latch system.

[0011] The standby power supply device 1 stores power supplied from the power supply 100. In addition, the standby power supply device 1 supplies power to the load device 200 when the power from the power supply 100 is cut off. The power supply 100 is also directly connected to the load device 200. The power supply 100 is connected to the load device 200 via a diode 71 to prevent reverse current flow.

[0012] The power source 100 is, for example, an in-vehicle battery. The load device 200 includes a load 210 and a load drive circuit 220 that drives the load 210. The load 210 is, for example, a motor in an electric latch system for an automobile door.

[0013] The standby power supply 1 includes a power storage circuit 10, a charging circuit 20, a boost circuit 30, an equalization / discharging circuit 40, and a measurement control section 50. Each of the components constituting the standby power supply 1 will be described below.

[0014] [Storage circuit 10] The storage circuit 10 is a circuit that stores electricity. The storage circuit 10 includes at least one electric double layer capacitor, a so-called supercapacitor. The storage circuit 10 of the standby power supply device 1 according to this embodiment includes an electric double layer capacitor 11 and an electric double layer capacitor 12 connected in series.

[0015] [Charging circuit 20] The charging circuit 20 charges the power storage circuit 10 with power supplied from the power source 100. The charging circuit 20 performs charging based on a charge control signal CTL1 from the measurement control unit 50.

[0016] [Boost circuit 30] The boost circuit 30 boosts the power supplied from the power storage circuit 10 and supplies the power to the load device 200. The boost circuit 30 supplies power based on a boost control signal CTL2 from the measurement control section 50. The boost circuit 30 is connected to the load device 200 via a diode 72 to prevent reverse current flow. The diode 72 may be omitted.

[0017] [Equalization / discharge circuit 40] The equalization / discharge circuit 40 performs an equalization process on the power storage circuit 10. The equalization / discharge circuit 40 also performs a discharge process on the power storage circuit 10. Fig. 2 is a diagram showing an example of the configuration of the equalization / discharge circuit 40 of the standby power supply device 1 according to this embodiment.

[0018] When electric double-layer capacitors such as supercapacitors are connected in series, an imbalance in voltage sharing among the capacitors may occur due to individual variations in leakage current. If an imbalance in voltage sharing among the capacitors occurs, even if the total rated voltage is within the rated voltage obtained by adding up the rated voltages of the individual capacitors, a voltage that exceeds the rated or set value may be applied to one of the capacitors when viewed from the perspective of each capacitor. In order to prevent a voltage that exceeds the rated or set value from being applied to the electric double-layer capacitor 11 or the electric double-layer capacitor 12, the equalization / discharge circuit 40 performs an equalization process to eliminate the voltage sharing imbalance and equalize the voltage applied to each capacitor.

[0019] The equalization / discharge circuit 40 performs an equalization process on the storage circuit 10 based on the equalization control signal CTL3. The equalization / discharge circuit 40 also performs a discharge process based on the discharge control signal CTL4. Furthermore, the equalization / discharge circuit 40 outputs a voltage signal SIGV1 of the electric double layer capacitor 11 and a voltage signal SIGV2 of the electric double layer capacitor 12 to the measurement control unit 50.

[0020] The equalization / discharge circuit 40 includes a switch 41, a switch 42, and resistors 45 and 46. The power storage circuit 10 includes an electric double layer capacitor 11 between the node N1 and a node N3. The power storage circuit 10 also includes an electric double layer capacitor 12 between the node N3 and a node N2. The node N1 is connected to the power supply 100 and the load device 200. The node N2 is grounded.

[0021] The switch 41 has a first terminal 41a and a second terminal 41b. The switch 41 connects or disconnects the first terminal 41a and the second terminal 41b. The switch 41 is provided between a node N1 and a resistor 45. The switch 41 is opened and closed based on an equalization control signal CTL3 and a discharge control signal CTL4. In the following description, the switch 41 may be referred to as a switch SW1.

[0022] The resistor 45 is provided between the switch 41 and the node N4. The resistors 45 and 46 are connected in series at the node N4. The resistor 45 has a resistance value R1.

[0023] The switch 42 has a first terminal 42a and a second terminal 42b. The switch 42 connects or disconnects the first terminal 42a and the second terminal 42b. The switch 42 is provided between a node N3 and a node N4. The switch 42 is opened and closed based on an equalization control signal CTL3 and a discharge control signal CTL4. In the following description, the switch 42 may be referred to as a switch SW2.

[0024] The resistor 46 is provided between the node N4 and the node N2. The resistor 46 has a resistance value R2. The resistance value R2 may be equal to the resistance value R1. The resistance values ​​being equal do not necessarily mean that they are completely the same, but also include, for example, that they are equal within a manufacturing error range.

[0025] The equalization / discharge circuit 40 outputs the voltage value Vsc1 at the node N1 as a voltage signal SIGV1 to the measurement control unit 50. The equalization / discharge circuit 40 also outputs the voltage value Vsc2 at the node N3 as a voltage signal SIGV2 to the measurement control unit 50. The voltage at the node N1 may be referred to as the terminal voltage Vsc of the storage circuit 10.

[0026] The first terminal 42a of the switch 42 is an example of a third terminal, and the second terminal 42b of the switch 42 is an example of a fourth terminal. Also, the node N1 is an example of a first node, the node N2 is an example of a second node, the node N3 is an example of a third node, and the node N4 is an example of a fourth node.

[0027] [Measurement control unit 50] The measurement control section 50 controls charging, power supply, and discharging of the power storage circuit 10. The measurement control section 50 also measures the characteristics of the power storage circuit 10. The measurement control section 50 is configured, for example, by an electronic control unit (ECU).

[0028] The measurement control unit 50 controls charging of the storage circuit 10 by the charging circuit 20 using a charge control signal CTL1. The measurement control unit 50 also controls power supply from the boost circuit 30 to the load device 200 using a boost control signal CTL2. The measurement control unit 50 controls the equalization process of the equalization / discharge circuit 40 using an equalization control signal CTL3.

[0029] Furthermore, the measurement control section 50 uses a discharge control signal CTL4 to control the discharge process of the equalization / discharge circuit 40. The measurement control section 50 controls the load drive circuit 220 using a drive control signal CTL5.

[0030] The measurement control unit 50 includes a timer for measuring time. The measurement control unit 50 calculates time using the number of counts from when the timer starts counting until when it stops.

[0031] <Measurement of Characteristics of Energy Storage Circuit 10 in Measurement Control Unit 50> Measurement of the characteristics of the power storage circuit 10 in the measurement control section 50 of the standby power supply device 1 according to this embodiment will be described. The characteristics of the power storage circuit 10 are determined from the capacitance value and the equivalent series resistance value of the power storage circuit 10.

[0032] [Capacitance value and equivalent series resistance value of the storage circuit 10] The characteristics of the power storage circuit 10 in the standby power supply device 1 according to this embodiment will be described below. Fig. 3 is an equivalent circuit diagram for measuring the capacitance value and the equivalent series resistance value of the power storage circuit in the standby power supply device 1 according to this embodiment.

[0033] In the energy storage circuit 10 according to this embodiment, the electric double layer capacitor 11 and the electric double layer capacitor 12 connected in series are regarded as one capacitor having a capacitance value Csc and one resistor having a resistance value ESRsc connected in series to the capacitor. The characteristics of the energy storage circuit 10 are evaluated using the capacitance value Csc and the resistance value ESRsc.

[0034] Moreover, the resistors 45 and 46 connected in series are evaluated as a discharge resistor R_discharge having a resistance value R (=resistance value R1+resistance value R2). That is, the resistance value R obtained by adding the resistance value R1 of the resistor 45 and the resistance value R2 of the resistor 46 is set as the resistance value of the discharge resistor R_discharge.

[0035] [Measurement of the capacitance value of the storage circuit 10] The characteristics of an electric double layer capacitor deteriorate with use. If the deterioration of the electric double layer capacitor progresses and the capacitance value decreases, it is possible that, for example, a problem will occur in the current supply to the motor, shortening the time that the capacitor can be used as a backup power source or making it impossible to release the latch. Therefore, in the standby power supply device 1 according to this embodiment, the capacitance value of the electric double layer capacitor is measured at any time to monitor the capacitance value.

[0036] 4 is a flow chart for measuring the capacity value of the power storage circuit 10 in the standby power supply device 1 according to this embodiment. When performing this process, the charging circuit 20 and the boost circuit 30 stop operating. That is, the power storage circuit 10 is not being charged from the power source 100. The power storage circuit 10 is not supplying power to the load device 200. When performing this process, the power storage circuit 10 is in a state where it is charged to a certain extent, for example, at least 50% of full charge, and preferably at least 80%.

[0037] The processing procedure of the measurement control unit 50 of the standby power supply 1 according to this embodiment and the steps of the control method of the standby power supply 1 will be described with reference to the flowchart of FIG.

[0038] (Step S10) First, the measurement control unit 50 turns on (closes) the switch SW1. When the switch SW1 is turned on (closed), the discharge resistor R_discharge is connected to the storage circuit 10. When the discharge resistor R_discharge is connected to the storage circuit 10, the power stored in the storage circuit 10 flows to the ground at a current I_R via the discharge resistor R_discharge. When the power stored in the storage circuit 10 flows to the ground at a current I_R, the terminal voltage Vsc of the storage circuit 10 gradually decreases.

[0039] (Step S20) Next, the measurement control section 50 measures the terminal voltage Vsc of the power storage circuit 10. Then, the measurement control section 50 records (acquires) the voltage value of the measured terminal voltage Vsc as the start voltage value V1. Also, the measurement control section 50 starts a timer count.

[0040] (Step S30) Next, the measurement control unit 50 judges whether the voltage value of the terminal voltage Vsc of the storage circuit 10 has become equal to or less than the end voltage value V2 set to a predetermined value. If the voltage value of the terminal voltage Vsc of the storage circuit 10 is greater than the predetermined end voltage value V2 (No in step S30), step S30 is repeated again. If the voltage value of the terminal voltage Vsc of the storage circuit 10 is equal to or less than the predetermined end voltage value V2 (Yes in step S30), the measurement control unit 50 advances the process to step S40. The end voltage value V2 is set to a value lower than the start voltage value V1.

[0041] (Step S40) Next, the measurement control unit 50 stops the timer count and records the count value. Then, the measurement control unit 50 calculates the time T from when the timer count starts to when it stops from the count value. It is desirable to execute the process of step S40 simultaneously with step S30 or as quickly as possible after executing step S30 within the range that the measurement control unit 50 can execute.

[0042] (Step S50) Next, the measurement control unit 50 turns off (opens) the switch SW1. When the switch SW1 turns off (opens), the discharge resistor R_discharge is disconnected from the power storage circuit 10.

[0043] (Step S60) Next, the measurement control unit 50 calculates the capacitance value Csc by Equation 1 using the measured start voltage value V1 and end voltage value V2 and the time T. Note that the resistance value R is the resistance value of the discharge resistor R_discharge. Ln represents the natural logarithm.

[0044]

number

[0045] (Step S70) Next, the measurement control unit 50 determines whether the storage circuit 10 is normal (degraded) based on the calculated capacitance value Csc. For example, if the capacitance value Csc is smaller than a predetermined capacitance value, the measurement control unit 50 determines that the storage circuit 10 is abnormal (degraded).

[0046] For example, in step S30, when the voltage value of the terminal voltage Vsc of the storage circuit 10 becomes equal to or lower than the end voltage value V2, the terminal voltage Vsc may be measured again and set as the end voltage value V2. Also, the set time Ts may be set first, and the voltage value of the terminal voltage Vsc of the storage circuit 10 when the time Ts has elapsed after the switch SW1 is turned on may be measured as the end voltage value V2.

[0047] The standby power supply device 1 of this embodiment can measure the capacitance value of the storage circuit 10 during discharging, in which current is released from the storage circuit 10. Furthermore, the standby power supply device 1 of this embodiment can monitor the deterioration of the characteristics of the electric double layer capacitor included in the storage circuit 10 by measuring the capacitance value of the storage circuit 10.

[0048] The equalization / discharge circuit 40 of the standby power supply 1 of this embodiment also operates as a discharge circuit that discharges the energy stored in the storage circuit 10. Therefore, the standby power supply 1 of this embodiment can check the operation of the discharge circuit by measuring the capacitance value of the storage circuit 10.

[0049] The start voltage value V1 is an example of a first voltage value, and the end voltage value V2 is an example of a second voltage value.

[0050] [Measurement of equivalent series resistance of storage circuit 10] The characteristics of an electric double layer capacitor deteriorate with use. If the deterioration of the electric double layer capacitor progresses and the equivalent series resistance value increases, it is possible that, for example, a problem will occur in the current supplied to the motor, making it impossible to release the latch. Therefore, in the standby power supply device 1 according to this embodiment, the equivalent series resistance value of the electric double layer capacitor is measured at any time to monitor the equivalent series resistance value.

[0051] 5 is a flow chart for measuring the equivalent series resistance of the power storage circuit 10 in the standby power supply device 1 according to this embodiment. When performing this process, the charging circuit 20 and the boost circuit 30 stop operating. That is, the power storage circuit 10 is not being charged from the power source 100. The power storage circuit 10 is not supplying power to the load device 200. When performing this process, the power storage circuit 10 is in a state where it is charged to a certain extent, for example, at least 50% of full charge, and preferably at least 80%.

[0052] The processing procedure of the measurement control unit 50 of the standby power supply 1 according to this embodiment and the steps of the control method of the standby power supply 1 will be described with reference to the flowchart of FIG.

[0053] (Step S110) First, the measurement control unit 50 turns on (closes) the switch SW1. When the switch SW1 is turned on (closed), the discharge resistor R_discharge is connected to the storage circuit 10. When the discharge resistor R_discharge is connected to the storage circuit 10, the power stored in the storage circuit 10 flows to the ground at a current I_R via the discharge resistor R_discharge. When the power stored in the storage circuit 10 flows to the ground at a current I_R, the terminal voltage Vsc of the storage circuit 10 gradually decreases.

[0054] (Step S120) Next, the measurement control unit 50 waits for a certain period of time. For example, the measurement control unit 50 waits for a certain period of time until the current I_R becomes stable.

[0055] (Step S130) Next, the measurement control unit 50 measures the terminal voltage Vsc of the power storage circuit 10. Then, the measurement control unit 50 stores (acquires) the voltage value of the measured terminal voltage Vsc as a conduction-time voltage value Vsc_on.

[0056] (Step S140) Next, the measurement control unit 50 turns off (opens) the switch SW1 immediately after measuring the terminal voltage Vsc of the energy storage circuit 10 in step S130. When the switch SW1 turns off (opens), the discharge resistor R_discharge is disconnected from the energy storage circuit 10. It is desirable to execute the process of step S140 simultaneously with step S130 or as quickly as possible after executing step S130 within the scope of the measurement control unit 50's feasibility.

[0057] (Step S150) Next, after the switch SW1 is turned off (open), the measurement control unit 50 measures the terminal voltage Vsc of the power storage circuit 10. Then, the measurement control unit 50 stores (acquires) the voltage value of the measured terminal voltage Vsc as a non-conducting voltage value Vsc_off.

[0058] (Step S160) Next, the measurement control unit 50 uses the measured conductive voltage value Vsc_on and non-conductive voltage value Vsc_off to calculate the equivalent series resistance value ESR according to Equation 2. Note that the resistance value R is the resistance value of the discharge resistance R_discharge.

[0059]

number

[0060] (Step S170) Next, the measurement control unit 50 determines whether the storage circuit 10 is normal (degraded) based on the calculated equivalent series resistance ESR. For example, when the equivalent series resistance ESR is greater than a predetermined resistance value, the measurement control unit 50 determines that the storage circuit 10 is abnormal (degraded).

[0061] The standby power supply device 1 of this embodiment can measure the equivalent series resistance of the storage circuit 10 during discharging, in which a current is released from the storage circuit 10. Furthermore, the standby power supply device 1 of this embodiment can monitor the deterioration of the characteristics of the electric double layer capacitor included in the storage circuit 10 by measuring the equivalent series resistance of the storage circuit 10.

[0062] Furthermore, the equalization / discharge circuit 40 of the standby power supply device 1 of this embodiment also operates as a discharge circuit that discharges the energy stored in the storage circuit 10. Therefore, the standby power supply device 1 of this embodiment can check the operation of the discharge circuit by measuring the equivalent series resistance value of the storage circuit 10.

[0063] The conductive voltage value Vsc_on is an example of a first voltage value, and the non-conductive voltage value Vsc_off is an example of a second voltage value.

[0064] [Simultaneous measurement of capacitance and equivalent series resistance of storage circuit 10] The standby power supply device 1 according to this embodiment can simultaneously measure the capacitance value and the equivalent series resistance value of the electric double layer capacitor at any time, and can simultaneously monitor the capacitance value and the equivalent series resistance value.

[0065] 6 is a flow chart for simultaneously measuring the capacitance and equivalent series resistance of the energy storage circuit 10 in the standby power supply device 1 according to this embodiment. When performing this process, the charging circuit 20 and the boost circuit 30 stop operating. That is, the energy storage circuit 10 is not being charged from the power source 100. The energy storage circuit 10 is not supplying power to the load device 200. When performing this process, the energy storage circuit 10 is in a state where it is charged to a certain extent, for example, at least 50% of full charge, and preferably at least 80%.

[0066] The processing procedure of the measurement control unit 50 of the standby power supply 1 according to this embodiment and the steps of the control method of the standby power supply 1 will be described with reference to the flowchart of FIG.

[0067] (Step S210) First, the measurement control unit 50 turns on (closes) the switch SW1. When the switch SW1 is turned on (closed), the discharge resistor R_discharge is connected to the storage circuit 10. When the discharge resistor R_discharge is connected to the storage circuit 10, the power stored in the storage circuit 10 flows to the ground at a current I_R via the discharge resistor R_discharge. When the power stored in the storage circuit 10 flows to the ground at a current I_R, the terminal voltage Vsc of the storage circuit 10 gradually decreases.

[0068] (Step S220) Next, the measurement control section 50 measures the terminal voltage Vsc of the power storage circuit 10. Then, the measurement control section 50 records (acquires) the voltage value of the measured terminal voltage Vsc as the start voltage value V1. Also, the measurement control section 50 starts a timer count.

[0069] (Step S230) Next, the measurement control unit 50 judges whether the voltage value of the terminal voltage Vsc of the storage circuit 10 has become equal to or less than the end voltage value V2 set to a predetermined value. If the voltage value of the terminal voltage Vsc of the storage circuit 10 is greater than the predetermined end voltage value V2 (No in step S230), step S230 is repeated again. If the voltage value of the terminal voltage Vsc of the storage circuit 10 is equal to or less than the predetermined end voltage value V2 (Yes in step S230), the measurement control unit 50 advances the process to step S240. The end voltage value V2 is set to a value lower than the start voltage value V1.

[0070] (Step S240) Next, the measurement control unit 50 stops the timer count and records the count value. Then, the measurement control unit 50 calculates the time T from when the timer count starts to when it stops from the count value. It is desirable to execute the process of step S240 simultaneously with step S230 or as quickly as possible after executing step S230 within the range that the measurement control unit 50 can execute.

[0071] (Step S250) Next, the measurement control unit 50 turns off (opens) the switch SW1 immediately after step S240. When the switch SW1 turns off (opens), the discharge resistor R_discharge is disconnected from the power storage circuit 10. It is desirable to execute the process of step S250 simultaneously with step S240 or as quickly as possible after executing step S240 within the range that the measurement control unit 50 can execute.

[0072] (Step S260) Next, after the switch SW1 is turned off (open), the measurement control unit 50 measures the voltage value of the terminal voltage Vsc of the power storage circuit 10. Then, the measurement control unit 50 stores the measured voltage value of the terminal voltage Vsc as a non-conducting voltage value V3.

[0073] (Step S270) Next, the measurement control unit 50 calculates the capacitance value Csc according to Equation 1 using the measured start voltage value V1 and end voltage value V2 and the time T. Note that the resistance value R is the resistance value of the discharge resistor R_discharge.

[0074] (Step S280) Next, the measurement control unit 50 uses the end voltage value V2 and the measured non-conduction voltage value V3 to calculate the equivalent series resistance ESR according to Equation 3. Note that the resistance value R is the resistance value of the discharge resistor R_discharge.

[0075]

number

[0076] (Step S290) Next, the measurement control unit 50 determines whether the storage circuit 10 is normal (degraded) based on the calculated capacitance value Csc. For example, if the capacitance value Csc is smaller than a predetermined capacitance value, the measurement control unit 50 determines that the storage circuit 10 is abnormal (degraded).

[0077] Furthermore, the measurement control unit 50 determines whether the storage circuit 10 is normal (degraded) based on the calculated equivalent series resistance ESR. For example, when the equivalent series resistance ESR is greater than a predetermined resistance value, the measurement control unit 50 determines that the storage circuit 10 is abnormal (degraded).

[0078] The standby power supply device 1 of this embodiment can measure the capacitance value and equivalent series resistance value of the storage circuit 10 during discharging, in which current is released from the storage circuit 10. Furthermore, the standby power supply device 1 of this embodiment can monitor the deterioration of the characteristics of the electric double layer capacitor provided in the storage circuit 10 by measuring the capacitance value and equivalent series resistance value of the storage circuit 10.

[0079] The start voltage value V1 is an example of a first voltage value, the end voltage value V2 is an example of a second voltage value, and the non-conduction voltage value V3 is an example of a third voltage value.

[0080] <Equalization of the storage circuit in the standby power supply device and measurement of the capacitance and equivalent series resistance> Next, the equalization process of the power storage circuit 10 in the standby power supply device 1 and the measurement of the capacitance value and the equivalent series resistance value will be described.

[0081] As described above, when an electric double layer capacitor is used as a backup energy source for an automobile system, it is necessary to monitor the capacitance and equivalent series resistance in order to manage the deterioration of the electric double layer capacitor in the actual use state. Therefore, a circuit for measuring the capacitance and equivalent series resistance in the vehicle mounted state is required.

[0082] Furthermore, in a circuit in which electric double layer capacitors are connected in series, an equalization circuit is required to eliminate voltage sharing imbalance. In the standby power supply device 1 according to this embodiment, the equalization / discharge circuit 40 measures the capacitance value and equivalent series resistance value, and performs equalization processing of the electric double layer capacitors.

[0083] Fig. 7 is a circuit diagram of a circuit for performing equalization processing and measuring the capacitance value and equivalent series resistance value of the storage circuit in the standby power supply device according to this embodiment. Fig. 8 is a flow chart for performing equalization processing and measuring the capacitance value and equivalent series resistance value of the storage circuit 10 in the standby power supply device 1 according to this embodiment.

[0084] The processing procedure of the measurement control unit 50 of the standby power supply 1 according to this embodiment and the steps of the control method of the standby power supply 1 will be described with reference to the flowchart of FIG.

[0085] The measurement control unit 50 determines whether the operation is normal (step S310). If the measurement control unit 50 determines that the operation is normal (Yes in step S310), the measurement control unit 50 opens the switches SW1 and SW2.

[0086] If the measurement control section 50 determines in step S10 that normal operation is not being performed (No in step S310), the measurement control section 50 determines whether the measurement is for an equivalent series resistance value or a capacitance value (step S330).

[0087] If the measurement control unit 50 determines that the equivalent series resistance or capacitance is to be measured (Yes in step S330), the measurement control unit 50 performs an opening / closing operation of only switch SW1 to measure the equivalent series resistance or capacitance (step S340). The measurement of the equivalent series resistance or capacitance is performed based on the above-mentioned procedure. After the measurement in step S340 is completed, switch SW1 is opened (step S350).

[0088] In step S340, the capacitance value of the energy storage circuit 10 may be measured, or the equivalent series resistance value of the energy storage circuit 10 may be measured. In addition, in step S340, the capacitance value and the equivalent series resistance value of the energy storage circuit 10 may be measured simultaneously.

[0089] The process of measuring the equivalent series resistance or capacitance in step S340 is an example of a first process.

[0090] On the other hand, if the measurement control unit 50 determines that the measurement is not for an equivalent series resistance or capacitance value (No in step S330), the measurement control unit 50 executes an equalization operation by simultaneously closing the switches SW1 and SW2 (step S360). After the equalization operation in step S360 is completed, the measurement control unit 50 opens the switches SW1 and SW2 (step S370).

[0091] The equalization operation in step S360 is an example of the second process.

[0092] The standby power supply 1 according to this embodiment can measure the capacitance value and the equivalent series resistance value, and perform the equalization process of the electric double layer capacitor, using a single circuit configuration. The standby power supply 1 according to this embodiment can reduce and simplify the complexity of the standby power supply 1 by measuring the capacitance value and the equivalent series resistance value, and performing the equalization process of the electric double layer capacitor, using a single circuit configuration.

[0093] The switch 41 is an example of a switch element. The switch 41 is an example of a first switch element, and the switch 42 is an example of a second switch element. The electric double layer capacitor 11 is an example of a first electric double layer capacitor, and the electric double layer capacitor 12 is an example of a second electric double layer capacitor. The resistor 45 is an example of a first discharge resistor, and the resistor 46 is an example of a second discharge resistor.

[0094] Although the standby power supply device has been described above by way of an embodiment, the present invention is not limited to the above embodiment. Various modifications and improvements, such as combinations or substitutions with part or all of other embodiments, are possible within the scope of the present invention. [Explanation of symbols]

[0095] 1 Standby Power Supply 10. Storage Circuit 11 Electric double layer capacitor 12 Electric double layer capacitor 20 Charging circuit 30 Boost circuit 40 Discharge circuit 41, 42 Switch 41a 1st terminal 41b 2nd terminal 45, 46 Resistance 50 Measurement control section 100 power supply 200 load device 210 Load 220 Load drive circuit N1 Node N2 Node N3 Node

Claims

1. a storage circuit having a first node connected to a power source and a second node grounded, the storage circuit including a first electric double layer capacitor and a second electric double layer capacitor connected in series between the first node and the second node; a first switch element having a first terminal connected to the first node and a second terminal, the first switch element connecting or disconnecting the first terminal and the second terminal; a first discharge resistor provided between the second terminal and a fourth node; a second discharge resistor provided between the fourth node and ground; a second switch element having a third terminal connected to a third node between the first electric double layer capacitor and the second electric double layer capacitor, and a fourth terminal connected to the fourth node, and connecting or disconnecting the third terminal and the fourth terminal; a measurement control unit that measures a voltage of the first node and controls the first switch element and the second switch element, The measurement control unit is As a first process, opening the third terminal and the fourth terminal by the second switch element and connecting the first terminal and the second terminal by the first switch element; measuring a voltage at the first node to obtain a first voltage value; determining whether the voltage at the first node is equal to or less than a second voltage value that is lower than the first voltage value; opening the first terminal and the second terminal by the first switch element when the voltage of the first node is equal to or lower than the second voltage value; calculating a time from when the first terminal and the second terminal are connected by the first switch element to when the first switch element is opened; calculating a capacitance value of the storage circuit based on the time, the first voltage value, and the second voltage value; As the second process, connecting the first terminal and the second terminal by the first switch element and connecting the third terminal and the fourth terminal by the second switch element; and after a predetermined time has elapsed, executing a procedure of opening the connection between the first terminal and the second terminal by the first switch element and opening the connection between the third terminal and the fourth terminal by the second switch element. Backup power supply.

2. The measurement control unit is Let the first voltage value be V1, the second voltage value be V2, the time be T, the sum of the resistance value of the first discharge resistor and the resistance value of the second discharge resistor be R, and the capacitance value be Csc. Then, the capacitance value is expressed as follows: [0010] Calculate by:

2. The standby power supply of claim 1.

3. The measurement control unit is executing a procedure for determining deterioration of the storage circuit based on the calculated capacitance value; 3. The standby power supply device according to claim 1 or 2.

4. The measurement control unit is a step of measuring a voltage at the first node and acquiring a third voltage value after the step of opening the first terminal and the second terminal by the first switch element; calculating an equivalent series resistance value of the storage circuit based on the second voltage value and the third voltage value; The standby power supply device according to any one of claims 1 to 3.

5. a storage circuit having a first node connected to a power source and a second node grounded, the storage circuit including a first electric double layer capacitor and a second electric double layer capacitor connected in series between the first node and the second node; a first switch element having a first terminal connected to the first node and a second terminal, the first switch element connecting or disconnecting the first terminal and the second terminal; a first discharge resistor provided between the second terminal and a fourth node; a second discharge resistor provided between the fourth node and ground; a third terminal connected to a third node between the first electric double layer capacitor and the second electric double layer capacitor, and a fourth terminal connected to the fourth node, and a second switch element for connecting or disconnecting the third terminal and the fourth terminal, comprising: As a first process, opening the third terminal and the fourth terminal by the second switch element and connecting the first terminal and the second terminal by the first switch element; measuring a voltage at the first node to obtain a first voltage value; determining whether the voltage at the first node is less than or equal to a second voltage value that is lower than the first voltage value; opening the first terminal and the second terminal by the first switch element when the voltage of the first node is equal to or lower than the second voltage value; calculating a time from when the first terminal and the second terminal are connected by the first switch element to when the first terminal is opened; calculating a capacitance value of the storage circuit based on the time, the first voltage value, and the second voltage value; As the second process, connecting the first terminal and the second terminal by the first switch element and connecting the third terminal and the fourth terminal by the second switch element; and after a predetermined time has elapsed, opening the connection between the first terminal and the second terminal by the first switch element and opening the connection between the third terminal and the fourth terminal by the second switch element. A method for controlling a standby power supply.

6. a storage circuit having a first node connected to a power source and a second node grounded, the storage circuit including a first electric double layer capacitor and a second electric double layer capacitor connected in series between the first node and the second node; a first switch element having a first terminal connected to the first node and a second terminal, the first switch element connecting or disconnecting the first terminal and the second terminal; a first discharge resistor provided between the second terminal and a fourth node; a second discharge resistor provided between the fourth node and ground; a second switch element having a third terminal connected to a third node between the first electric double layer capacitor and the second electric double layer capacitor, and a fourth terminal connected to the fourth node, and connecting or disconnecting the third terminal and the fourth terminal; a measurement control unit that measures a voltage of the first node and controls the first switch element and the second switch element, The measurement control unit is As a first process, opening the third terminal and the fourth terminal by the second switch element and connecting the first terminal and the second terminal by the first switch element; measuring a voltage at the first node to obtain a first voltage value; immediately after measuring the voltage of the first node, opening the first terminal and the second terminal by the first switch element; a step of measuring a voltage of the first node after the first terminal and the second terminal are opened by the first switch element, and acquiring a second voltage value lower than the first voltage value; calculating an equivalent series resistance of the storage circuit based on the first voltage value and the second voltage value; As the second process, connecting the first terminal and the second terminal by the first switch element and connecting the third terminal and the fourth terminal by the second switch element; and after a predetermined time has elapsed, executing a procedure of opening the connection between the first terminal and the second terminal by the first switch element and opening the connection between the third terminal and the fourth terminal by the second switch element. Backup power supply.

7. The measurement control unit is Let V1 be the first voltage value, V2 be the second voltage value, R be the sum of the resistance value of the first discharge resistor and the resistance value of the second discharge resistor, and ESR be the equivalent series resistance value, [0025] Calculate by:

7. The standby power supply of claim 6.

8. The measurement control unit executes a procedure for determining deterioration of the storage circuit based on the calculated equivalent series resistance value.

8. A standby power supply device according to claim 6 or 7.

9. a storage circuit having a first node connected to a power source and a second node grounded, the storage circuit including a first electric double layer capacitor and a second electric double layer capacitor connected in series between the first node and the second node; a first switch element having a first terminal connected to the first node and a second terminal, the first switch element connecting or disconnecting the first terminal and the second terminal; a first discharge resistor provided between the second terminal and a fourth node; a second discharge resistor provided between the fourth node and ground; a third terminal connected to a third node between the first electric double layer capacitor and the second electric double layer capacitor, and a fourth terminal connected to the fourth node, and a second switch element for connecting or disconnecting the third terminal and the fourth terminal, As a first process, opening the third terminal and the fourth terminal by the second switch element and connecting the first terminal and the second terminal by the first switch element; measuring a voltage at the first node to obtain a first voltage value; immediately after measuring the voltage of the first node, opening the first terminal and the second terminal by the first switch element; measuring a voltage at the first node after opening the first terminal and the second terminal by the first switch element, and acquiring a second voltage value lower than the first voltage value; calculating an equivalent series resistance value of the storage circuit based on the first voltage value and the second voltage value; As the second process, connecting the first terminal and the second terminal by the first switch element and connecting the third terminal and the fourth terminal by the second switch element; and after a predetermined time has elapsed, opening the connection between the first terminal and the second terminal by the first switch element and opening the connection between the third terminal and the fourth terminal by the second switch element. A method for controlling a standby power supply.

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