Solar charging system, method, and vehicle

Abstract

To provide a solar charging system and the like that can identify a DCDC converter in which an abnormality has occurred when the abnormality occurs in a system.SOLUTION: A solar charging system includes a solar panel, a first power conversion device which is configured to be capable of detecting or deriving input power and output power, and receives power generated by the solar panel, a second power conversion device which is configured to be capable of detecting or deriving input power and output power, and receives power output by the first power conversion device, and a processor which determines occurrence of an abnormality in at least the first power conversion device and the second power conversion device based on the comparison between the input power and the output power of the first power conversion device and the second power conversion device.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a solar charging system that controls charging of a battery using power generated by a solar panel. [Background technology]

[0002] Patent document 1 discloses a solar charging system including two solar panels, two solar DCDC converters corresponding to each solar panel, a high-voltage DCDC converter that supplies the output power of the solar DCDC converter to a high-voltage battery, and an auxiliary DCDC converter that supplies the output power of the solar DCDC converter to an auxiliary battery. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-087291 Summary of the Invention [Problem to be solved by the invention]

[0004] In the system equipped with a plurality of DC-DC converters described in Patent Document 1, when an abnormality occurs in the system, it is desirable to be able to identify the DC-DC converter related to the location where the abnormality occurs.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a solar charging system and the like that can identify the DC-DC converter in which an abnormality occurs when an abnormality occurs in the system. [Means for solving the problem]

[0006] In order to solve the above problems, one aspect of the disclosed technology is a solar charging system comprising a solar panel, a first power conversion device configured to be able to detect or derive input power and output power and inputting the generated power of the solar panel, a second power conversion device configured to be able to detect or derive input power and output power and inputting the power output by the first power conversion device, and a processing unit that, when an abnormality occurs in the system, determines the occurrence of an abnormality for at least the first power conversion device and the second power conversion device based on a comparison of the input power and output power of the first power conversion device and the second power conversion device. Effect of the Invention

[0007] According to the solar charging system and the like of the present disclosure, when an abnormality occurs in the system, it is possible to identify the location of the power conversion device (DC-DC converter) where the abnormality occurs. [Brief description of the drawings]

[0008] [Figure 1] 1 is a schematic configuration diagram of a solar charging system according to an embodiment of the present invention; [Diagram 2] Example of an auxiliary DDC circuit [Diagram 3] Flowchart of abnormality control process (first example) executed by the solar charging system [Figure 4] Flowchart of the auxiliary DDC fail-safe process executed by the solar charging system [Diagram 5] Flowchart of abnormality control process (second example) executed by the solar charging system DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] In the case of an abnormality occurring in the system, the solar charging system according to the present disclosure aims to improve the uptime and reliability of the system by accurately identifying the location of the abnormality based on the power balance between the input and output of each DCDC converter. Hereinafter, an embodiment of the present disclosure will be described in detail with reference to the drawings.

[0010] <Embodiment> [composition] Fig. 1 is a block diagram showing a schematic configuration of a solar charging system according to an embodiment of the present disclosure. The solar charging system 1 shown in Fig. 1 includes two solar panels 11 and 12, two solar DDCs 21 and 22, a high-voltage DDC 30, an auxiliary DDC 40, a high-voltage battery 50, an auxiliary battery 60, a capacitor 70, and a processing unit 100. This solar charging system 1 can be mounted on a vehicle or the like.

[0011] The solar panels 11 and 12 are power generating devices that generate power by receiving irradiation of sunlight, and are typically solar cell modules that are an assembly of solar cell cells. The solar panels 11 and 12 can be installed, for example, on the roof of a vehicle. One solar panel 11 is connected to one solar DDC 21 described later, and the power generated by the solar panel 11 is output to the solar DDC 21. The other solar panel 12 is connected to the other solar DDC 22 described later, and the power generated by the solar panel 12 is output to the solar DDC 22. The solar panels 11 and 12 may all be the same in performance, capacity, size, shape, etc., or may be partially or entirely different.

[0012] The solar DDCs 21 and 22 are DCDC converters (first DCDC converters) provided corresponding to the solar panels 11 and 12, and supply the electric power generated by the solar panels 11 and 12, respectively, to the high voltage DDC 30 and the auxiliary DDC 40. When supplying electric power, the solar DDC 21 can convert (boost / step down) the generated voltage of the solar panel 11, which is the input voltage, to a predetermined voltage and output it to the high voltage DDC 30 and the auxiliary DDC 40. When supplying electric power, the solar DDC 22 can convert (boost / step down) the generated voltage of the solar panel 12, which is the input voltage, to a predetermined voltage and output it to the high voltage DDC 30 and the auxiliary DDC 40. In this way, the solar DDCs 21 and 22 function as "first power conversion devices" that can convert the input power from the solar panels 11 and 12 to a desired output power. The solar DDC 21 includes a configuration (not shown) capable of detecting or deriving the power of the input side [A] to which the solar panel 11 is connected and the power of the output side [B] to which the high voltage DDC 30 and the auxiliary DDC 40 are connected. The solar DDC 22 also includes a configuration (not shown) capable of detecting or deriving the power of the input side [C] to which the solar panel 12 is connected and the power of the output side [D] to which the high voltage DDC 30 and the auxiliary DDC 40 are connected. These powers can be detected, for example, by detecting the input / output power of the solar DDCs 21 and 22 using a power sensor (not shown), or by detecting the input / output voltages and input / output currents of the solar DDCs 21 and 22 using a voltage sensor and a current sensor (not shown) to derive the input / output power. The configurations and performances of the solar DDCs 21 and 22 may be the same or may be different depending on the solar panels 11 and 12.

[0013] The above-mentioned solar panels 11 and 12, and solar DDCs 21 and 22, the solar panel 11 and the solar DDC 21 form one panel power generation control unit, and the solar panel 12 and the solar DDC 22 form one panel power generation control unit. In the solar charging system 1 of the present embodiment, a configuration in which these two panel power generation control units are provided in parallel is described as an example, but the solar charging system may be configured with only one panel power generation control unit, or may be configured with three or more panel power generation control units provided in parallel.

[0014] The high-voltage DDC 30 is a DCDC converter (second DCDC converter) that supplies the power output by the solar DDCs 21 and 22 to the high-voltage battery 50. When supplying power, the high-voltage DDC 30 can convert (boost) the output voltage of the solar DDCs 21 and 22, which is the input voltage, to a predetermined voltage and output it to the high-voltage battery 50. This high-voltage DDC 30 includes a configuration (not shown) that can detect or derive the power of the input side [E] to which the solar DDCs 21 and 22 are connected and the power of the output side [F] to which the high-voltage battery 50 is connected. This power can be detected, for example, by detecting the input / output power of the high-voltage DDC 30 using a power sensor (not shown), or by detecting the input / output voltage and input / output current of the high-voltage DDC 30 using a voltage sensor or current sensor (not shown) to derive the input / output power.

[0015] The auxiliary DDC 40 is a DCDC converter (third DCDC converter) that supplies the power output by the solar DDCs 21 and 22 to the auxiliary battery 60. When supplying power, the auxiliary DDC 40 can convert (step down) the output voltage of the solar DDCs 21 and 22, which is the input voltage, to a predetermined voltage and output it to the auxiliary battery 60. The auxiliary DDC 40 of this embodiment is configured by connecting two or more converter circuits in parallel to increase the outputtable power capacity.

[0016] Fig. 2 shows a detailed circuit example of the auxiliary DDC 40 configured by connecting two converter circuits in parallel. The auxiliary DDC 40 illustrated in Fig. 2 has a first converter circuit consisting of a switching element M11, a switching element M12, and an inductor L1, and a second converter circuit consisting of a switching element M21, a switching element M22, and an inductor L2 connected in parallel. The ON / OFF operation of each of the switching elements M11, M12, M21, and M22 is controlled by a drive circuit 41. The auxiliary DDC 40 also includes an input voltage sensor 42 that detects the voltage of the input side [G], an input current sensor 43 that detects the current flowing into the circuit from the input side [G], an output voltage sensor 44 that detects the voltage of the output side [H], a first output current sensor 45 that detects the current flowing out from the first converter circuit toward the output side [H], and a second output current sensor 46 that detects the current flowing out from the second converter circuit toward the output side [H]. The voltage and current values ​​detected by these sensors, or the values ​​of the power on the input side [G] and the power on the output side [H] derived from the voltage and current, are output to the processing unit 100. Note that the input current sensor 43 can be omitted when implementing a second example of the abnormality control process described later.

[0017] The high voltage DDC 30 and the auxiliary DDC 40 described above function as a "second power conversion device" that can convert the input power from the solar DDCs 21 and 22, which are the first power conversion devices, into a desired output power.

[0018] The high-voltage battery 50 is a secondary battery configured to be chargeable and dischargeable, such as a lithium-ion battery or a nickel-metal hydride battery. The high-voltage battery 50 is connected to the high-voltage DDC 30 so as to be chargeable by the power output by the high-voltage DDC 30. An example of the high-voltage battery 50 mounted on a vehicle is a so-called drive battery that can supply power required for the operation of main equipment (not shown) for driving the vehicle, such as a starter motor or an electric motor.

[0019] The auxiliary battery 60 is a secondary battery configured to be chargeable and dischargeable, such as a lithium ion battery or a lead storage battery. The auxiliary battery 60 is connected to the auxiliary DDC 40 so as to be chargeable by the power output by the auxiliary DDC 40. The auxiliary battery 60 mounted on the vehicle is a battery that can supply power required for the operation of auxiliary devices (not shown) other than those for driving the vehicle, such as lighting devices such as headlamps and interior lights, air conditioners such as heaters and coolers, and devices for automatic driving and advanced driving assistance.

[0020] The capacitor 70 is connected between the solar DDCs 21 and 22 (first power conversion devices) and the high voltage DDC 30 and auxiliary DDC 40 (second power conversion devices). This capacitor 70 is a large-capacitance element used to charge and discharge the power generated by the solar panels 11 and 12 as necessary, and to stabilize the voltage generated between the output of the solar DDCs 21 and 22 and the input of the high voltage DDC 30 and auxiliary DDC 40. Note that this capacitor 70 may be omitted from the configuration of the solar charging system 1.

[0021] The processing unit 100 acquires the input power (or the input voltage and input current for derivation) and the output power (or the output voltage and output current for derivation) detected in each of the solar DDC 21, the solar DDC 22, the high voltage DDC 30, and the auxiliary DDC 40. When an abnormality occurs in the solar charging system 1, the processing unit 100 identifies the DCDC converter in which an abnormality (such as a sensor abnormality or a circuit abnormality) occurs based on the input power and the output power acquired from the solar DDC 21, the solar DDC 22, the high voltage DDC 30, and the auxiliary DDC 40, and performs necessary processing on the system.

[0022] In addition, the solar DDCs 21 and 22, the high voltage DDC 30, the auxiliary DDC 40, and some or all of the processing unit 100 can be configured as an electronic control unit (ECU) that typically includes a processor, a memory, an input / output interface, etc. This electronic control unit can perform the various controls described above by having the processor read and execute a program stored in the memory.

[0023] [control] Next, with further reference to Figs. 3 to 5, several examples of abnormality control processes executed by the solar charging system 1 when an abnormality occurs in the solar charging system 1 will be described.

[0024] (1) First Example Fig. 3 is a flowchart illustrating a first example of the abnormality control process executed by the processing unit 100 of the solar charging system 1. The abnormality control process of the first example shown in Fig. 3 is started, for example, when the ignition of the vehicle is turned on.

[0025] (Step S301) The processing unit 100 calculates the current deviation of the auxiliary DDC 40. The current deviation of the auxiliary DDC 40 is a difference value between the current output from the first converter circuit (M11, M12, L1) of the auxiliary DDC 40 and the current output from the second converter circuit (M21, M22, L2). The processing unit 100 acquires the current value detected by the first output current sensor 45 from the auxiliary DDC 40 and the current value detected by the second output current sensor 46, and calculates the difference between these values ​​to calculate a current difference value (current deviation). When the auxiliary DDC 40 is configured by connecting three or more converter circuits in parallel, a difference value between each two of the currents flowing through each converter circuit is calculated. When the current deviation of the auxiliary DDC 40 is calculated, the process proceeds to step S302.

[0026] (Step S302) The processing unit 100 judges whether the current deviation of the auxiliary DDC40 is abnormal. This judgment is made based on whether the absolute value of the current difference value between the first converter circuit (M11, M12, L1) and the second converter circuit (M21, M22, L2) of the auxiliary DDC40 exceeds a predetermined threshold value. The predetermined threshold value can be set to a predetermined value based on a current difference value that is allowed in a state in which both the first converter circuit and the second converter circuit are operating normally, taking into consideration the variations and performance of the switching elements, inductors, and output current sensors. If the current deviation of the auxiliary DDC40 is abnormal (step S302, Yes), the process proceeds to step S303. On the other hand, if the current deviation of the auxiliary DDC40 is normal (step S302, No), the abnormality control process of this first example is terminated.

[0027] (Step S303) The processing unit 100 calculates the power balance between the input and output of each of the solar DDC21, the solar DDC22, and the high voltage DDC30. More specifically, the processing unit 100 acquires the power (or the input voltage and input current for derivation) of the input side [A] of the solar DDC21 and the power (or the output voltage and output current for derivation) of the output side [B] of the solar DDC21 from the solar DDC21, and calculates the difference value between the acquired input power and output power as the power balance of the solar DDC21. The processing unit 100 also acquires the power (or the input voltage and input current for derivation) of the input side [C] of the solar DDC22 and the power (or the output voltage and output current for derivation) of the output side [D] of the solar DDC22 from the solar DDC22, and calculates the difference value between the acquired input power and output power as the power balance of the solar DDC22. The processing unit 100 also acquires the power (or the input voltage and input current for derivation) of the input side [E] of the high voltage DDC 30 and the power (or the output voltage and output current for derivation) of the output side [F] of the high voltage DDC 30 from the high voltage DDC 30, and calculates the difference between the acquired input power and output power as the power balance of the high voltage DDC 30. When acquiring the voltage, the output side [B] of the solar DDC 21, the output side [D] of the solar DDC 22, and the input side [E] of the high voltage DDC 30 are electrically connected to each other and have the same potential, so any one of the voltages may be shared. When the power balance between the input and output of the solar DDC 21, the solar DDC 22, and the high voltage DDC 30 is calculated, the process proceeds to step S304.

[0028] (Step S304) The processing unit 100 judges whether the power balance between the input and output of the solar DDC 21, the solar DDC 22, and the high-voltage DDC 30 is all normal. This judgment is made to confirm whether the solar DDC 21, the solar DDC 22, and the high-voltage DDC 30 are operating normally. Specifically, since the input power and the output power are approximately equal if the DDC converter is operating normally, the processing unit 100 compares the input power and the output power and judges whether the operation is normal / abnormal based on whether the difference value is equal to or less than a predetermined value close to zero. If the power balance of each DDC is all normal (step S304, Yes), the process proceeds to step S305. On the other hand, if the power balance of at least one DDC is not normal (step S304, No), the process proceeds to step S309.

[0029] (Step S305) The processing unit 100 calculates the power balance of the midpoint power due to the solar DDC21, the solar DDC22, the high voltage DDC30, the auxiliary DDC40, and the capacitor 70. More specifically, the processing unit 100 calculates the power balance of the power line (midpoint) to which the output of the solar DDC21, the output of the solar DDC22, the input of the high voltage DDC30, the input of the auxiliary DDC40, and the capacitor 70 are connected. The processing unit 100 acquires the power (or the output voltage and output current for derivation) of the output side [B] of the solar DDC 21, the power (or the output voltage and output current for derivation) of the output side [D] of the solar DDC 22, the power (or the input voltage and input current for derivation) of the input side [E] of the high-voltage DDC 30, the power (or the input voltage and input current for derivation) of the input side [G] of the auxiliary DDC 40, and the charge / discharge power (terminal voltage and input / output current) of the capacitor 70, and calculates the difference value (XY) between the total X (= [B] + [D] + discharge power) of each of the acquired output powers and discharge powers and the total Y (= [E] + [G] + charge power) of each of the input powers and charge powers as the power balance of the midpoint power. In addition, since the voltage at this midpoint is the same value (same potential) for the output side of the solar DDC 21, the output side of the solar DDC 22, the input side of the high voltage DDC 30, the input side of the auxiliary DDC 40, and the capacitor 70, it is possible to determine normality / abnormality, which will be described later, even if the current balance is calculated instead of the power balance. Once the power balance of the midpoint power by each DDC and capacitor is calculated, the process proceeds to step S306.

[0030] (Step S306) The processing unit 100 judges whether the power balance of the midpoint power by the solar DDC21, the solar DDC22, the high voltage DDC30, the auxiliary DDC40, and the capacitor 70 is normal. This judgment is made to confirm whether the abnormality occurring in the auxiliary DDC40 occurs on the input side [G] or the output side [H]. Specifically, if the input side [G] of the auxiliary DDC40 is normal, the input power and the output power at the midpoint between the solar DDC21, the solar DDC22, and the high voltage DDC30 that are confirmed to be operating normally and the auxiliary DDC40 are approximately equal, so the processing unit 100 compares the input power and the output power and judges whether the operation is normal / abnormal based on whether the difference value is equal to or less than a predetermined value close to zero. If the power balance of the midpoint power is normal (step S306, Yes), the process proceeds to step S307. On the other hand, if the power balance of the midpoint power is abnormal (step S306, No), the process proceeds to step S308.

[0031] (Step S307) The processing unit 100 determines that an abnormality occurs only in the auxiliary device DDC 40, and that the location of the abnormality is the output side [H] of the auxiliary device DDC 40. When the location of the abnormality in the auxiliary device DDC 40 is determined, the process proceeds to step S310.

[0032] (Step S308) The processing unit 100 determines that an abnormality occurs only in the auxiliary DDC 40, and that the location of the abnormality is the input side [G] of the auxiliary DDC 40. When the location of the abnormality in the auxiliary DDC 40 is determined, the process proceeds to step S311.

[0033] (Step S309) The processing unit 100 determines that an abnormality has occurred in a plurality of DDCs. The plurality of DDCs are the auxiliary DDC 40 and the DDC whose input / output power balance has been determined to be abnormal in the above step S304. When a plurality of DDCs in which an abnormality has occurred are determined, the process proceeds to step S311.

[0034] (Step S310) The processing unit 100 performs a fail-safe process for the auxiliary DDC 40 in which an abnormality occurs on the output side [H]. This fail-safe process will be described later. When the fail-safe process for the auxiliary DDC 40 is performed, the abnormality control process of the first example ends.

[0035] (Step S311) The processing unit 100 determines that the charging process using the power generated by the solar panels 11 and 12 cannot be continued, and stops the solar charging system 1. This ends the abnormality control process of the first example.

[0036] By the processing of steps S301 to S311, it is possible to accurately identify the DDC in which the abnormality (sensor abnormality, circuit abnormality, etc.) occurs when an abnormality occurs in the solar charging system 1. Furthermore, in the auxiliary DDC 40 that employs a parallel configuration of converter circuits, it is possible to accurately determine whether the abnormality occurs on the input side or the output side.

[0037] FIG. 4 is a flowchart illustrating an example of the fail-safe processing of the auxiliary DDC 40, which is executed by the processing unit 100 of the solar charging system 1 in step S310 in FIG.

[0038] (Step S401) The processing unit 100 calculates the power balance between the input and output of the first converter circuit (M11, M12, L1) of the auxiliary device DDC40. More specifically, in a state in which the first converter circuit is operated by the drive circuit 41 and the second converter circuit is stopped, the processing unit 100 acquires the voltage of the input voltage sensor 42 and the current of the input current sensor 43 to calculate the input power of the first converter circuit, and acquires the voltage of the output voltage sensor 44 and the current of the first output current sensor 45 to calculate the output power of the first converter circuit. Then, the processing unit 100 calculates the difference value between the calculated input power and output power as the power balance between the input and output of the first converter circuit of the auxiliary device DDC40. When the power balance of the first converter circuit is calculated, the process proceeds to step S402.

[0039] (Step S402) The processing unit 100 calculates the power balance between the input and output of the second converter circuit (M21, M22, L2) of the auxiliary device DDC40. More specifically, the processing unit 100 acquires the voltage of the input voltage sensor 42 and the current of the input current sensor 43 to calculate the input power of the second converter circuit, and acquires the voltage of the output voltage sensor 44 and the current of the second output current sensor 46 to calculate the output power of the second converter circuit, while the first converter circuit is stopped and the second converter circuit is operated by the drive circuit 41. Then, the processing unit 100 calculates the difference value between the calculated input power and output power as the power balance between the input and output of the second converter circuit of the auxiliary device DDC40. When the power balance of the second converter circuit is calculated, the process proceeds to step S403.

[0040] (Step S403) The processing unit 100 judges whether the power balance between the input and output of the first converter circuit (M11, M12, L1) and the power balance between the input and output of the second converter circuit (M21, M22, L2) in the auxiliary DDC40 are both abnormal. This judgment is made to confirm whether one of the parallel converter circuits is operating normally. Specifically, since the input power and the output power are approximately equal if the converter circuit is operating normally, the input power and the output power are compared to judge whether the difference between them is equal to or less than a predetermined value close to zero. If the power balances of both converter circuits are abnormal (step S403, Yes), the process proceeds to step S404. On the other hand, if only the power balance of one converter circuit is abnormal (step S403, No), the process proceeds to step S405.

[0041] (Step S404) The processing unit 100 identifies both the first converter circuit (M11, M12, L1) and the second converter circuit (M21, M22, L2) as abnormal parts, and stops the auxiliary DDC 40. That is, the solar charging system 1 is stopped. This ends the fail-safe processing of the auxiliary DDC 40.

[0042] (Step S405) The processing unit 100 identifies one of the first converter circuit (M11, M12, L1) and the second converter circuit (M21, M22, L2) of the auxiliary DDC 40 as an abnormal part, and identifies the other as normal. Then, the processing unit 100 continues the operation of the solar charging control as a system using the converter circuit that is operating normally. When the operation of the solar charging control is continued, the fail-safe processing of the auxiliary DDC 40 ends.

[0043] By the processing of steps S401 to S405, even if an abnormality occurs in the solar charging system 1, if the abnormality is only in one of the parallel converter circuits in the auxiliary DDC 40, the solar charging control operation by the system can be continued using the normal converter circuit. This control improves the availability of the auxiliary DDC 40 in the fail-safe processing, and increases the reliability of the auxiliary DDC 40 in the system.

[0044] In the abnormality control process of the first example, it has been described that when a sensor abnormality occurs on the input side [G] of the auxiliary DDC 40 (step S308), the solar charging system 1 is immediately stopped. However, even if a sensor abnormality occurs on the input side [G] of the auxiliary DDC 40, if it is determined in the fail-safe process that one of the converter circuits of the auxiliary DDC 40 is normal, power conversion can be performed using this normally operating converter circuit, so it is possible to continue the operation of the solar charging control as a system. However, in this case, it is assumed that at least one of the solar DDC 21 and the solar DDC 22 is normal, and the power generated by the solar panel is supplied to the auxiliary DDC 40 by the normal solar DDC.

[0045] (2) Second Example Fig. 5 is a flowchart for explaining a second example of the abnormality control process executed by the processing unit 100 of the solar charging system 1. This second example of the abnormality control process is useful when the processing unit 100 cannot acquire the current flowing in from the input side [G] of the auxiliary DDC 40, for example, when the auxiliary DDC 40 is configured not to include the input current sensor 43 (see Fig. 2). The abnormality control process of the second example shown in Fig. 5 is started, for example, when the ignition of the vehicle is turned on.

[0046] (Step S501) The processing unit 100 calculates a current deviation of the auxiliary DDC 40. The current deviation of the auxiliary DDC 40 is a difference value between a current output from a first converter circuit (M11, M12, L1) of the auxiliary DDC 40 and a current output from a second converter circuit (M21, M22, L2). The processing unit 100 acquires a current value detected by a first output current sensor 45 from the auxiliary DDC 40 and a current value detected by a second output current sensor 46, and calculates a current difference value (current deviation) by taking a difference between these values. When the current deviation of the auxiliary DDC 40 is calculated, the process proceeds to step S502.

[0047] (Step S502) The processing unit 100 judges whether the current deviation of the auxiliary DDC40 is abnormal. This judgment is made based on whether the absolute value of the current difference value between the first converter circuit (M11, M12, L1) and the second converter circuit (M21, M22, L2) of the auxiliary DDC40 exceeds a predetermined threshold value. The predetermined threshold value can be set to a predetermined value based on a current difference value that is permissible in a state in which both the first converter circuit and the second converter circuit are operating normally, taking into consideration the variations and performance of the switching elements, inductors, and output current sensors. If the current deviation of the auxiliary DDC40 is abnormal (step S502, Yes), the process proceeds to step S503. On the other hand, if the current deviation of the auxiliary DDC40 is normal (step S502, No), the abnormality control process of the second example is terminated.

[0048] (Step S503) The processing unit 100 calculates the power balance between the input and output of each of the solar DDC21, the solar DDC22, and the high voltage DDC30. More specifically, the processing unit 100 acquires the power (or the input voltage and input current for derivation) of the input side [A] of the solar DDC21 and the power (or the output voltage and output current for derivation) of the output side [B] of the solar DDC21 from the solar DDC21, and calculates the difference value between the acquired input power and output power as the power balance of the solar DDC21. The processing unit 100 also acquires the power (or the input voltage and input current for derivation) of the input side [C] of the solar DDC22 and the power (or the output voltage and output current for derivation) of the output side [D] of the solar DDC22 from the solar DDC22, and calculates the difference value between the acquired input power and output power as the power balance of the solar DDC22. The processing unit 100 also acquires the power (or the input voltage and input current for derivation) of the input side [E] of the high voltage DDC 30 and the power (or the output voltage and output current for derivation) of the output side [F] of the high voltage DDC 30 from the high voltage DDC 30, and calculates the difference between the acquired input power and output power as the power balance of the high voltage DDC 30. When acquiring the voltage, the output side [B] of the solar DDC 21, the output side [D] of the solar DDC 22, and the input side [E] of the high voltage DDC 30 are electrically connected to each other and have the same potential, so any one of the voltages may be shared. When the power balance between the input and output of the solar DDC 21, the solar DDC 22, and the high voltage DDC 30 is calculated, the process proceeds to step S504.

[0049] (Step S504) The processing unit 100 judges whether the power balance between the input and output of the solar DDC 21, the solar DDC 22, and the high-voltage DDC 30 is all normal. This judgment is made to confirm whether the solar DDC 21, the solar DDC 22, and the high-voltage DDC 30 are operating normally. Specifically, since the input power and the output power are approximately equal if the DDC converter is operating normally, the processing unit 100 compares the input power and the output power and judges whether the operation is normal / abnormal based on whether the difference value is equal to or less than a predetermined value close to zero. If the power balance of each DDC is all normal (step S504, Yes), the process proceeds to step S505. On the other hand, if the power balance of at least one DDC is not normal (step S504, No), the process proceeds to step S508.

[0050] (Step S505) The processing unit 100 calculates the input power of the auxiliary DDC 40 from the midpoint power of the solar DDC 21, the solar DDC 22, the high voltage DDC 30, and the capacitor 70. More specifically, the processing unit 100 acquires the power (or the output voltage and output current for derivation) of the output side [B] of the solar DDC 21, the power (or the output voltage and output current for derivation) of the output side [D] of the solar DDC 22, the power (or the input voltage and input current for derivation) of the input side [E] of the high voltage DDC 30, and the charge / discharge power (terminal voltage and input / output current) of the capacitor 70, and calculates (estimates) the value (XZ) obtained by subtracting the total Z (= [E] + charge power) of the input power and charge power from the total X (= [B] + [D] + discharge power) of the acquired output power and discharge power, as the power of the input side [G] of the auxiliary DDC 40. When the input power of the auxiliary DDC 40 is calculated, the process proceeds to step S506.

[0051] (Step S506) The processing unit 100 calculates the power balance between the input and output of the first converter circuit (M11, M12, L1) of the auxiliary DDC40. More specifically, the processing unit 100 acquires the voltage of the input voltage sensor 42 and the current of the input current sensor 43 to calculate the input power of the first converter circuit, and acquires the voltage of the output voltage sensor 44 and the current of the first output current sensor 45 to calculate the output power of the first converter circuit, while the first converter circuit is operated by the drive circuit 41 and the second converter circuit is stopped. Then, the processing unit 100 calculates the difference value between the calculated input power and output power as the power balance between the input and output of the first converter circuit of the auxiliary DDC40. The processing unit 100 also calculates the power balance between the input and output of the second converter circuit (M21, M22, L2) of the auxiliary DDC40. More specifically, in a state where the first converter circuit is stopped and the second converter circuit is operated by the drive circuit 41, the processing unit 100 acquires the voltage of the input voltage sensor 42 and the current of the input current sensor 43 to calculate the input power of the second converter circuit, and acquires the voltage of the output voltage sensor 44 and the current of the second output current sensor 46 to calculate the output power of the second converter circuit. Then, the processing unit 100 calculates the difference value between the calculated input power and output power as the power balance between the input and output of the second converter circuit of the auxiliary DDC 40. When the power balance of the first converter circuit and the power balance of the second converter circuit are respectively calculated, the process proceeds to step S507.

[0052] (Step S507) The processing unit 100 judges whether the power balance between the input and output of the first converter circuit (M11, M12, L1) and the power balance between the input and output of the second converter circuit (M21, M22, L2) in the auxiliary DDC40 are both abnormal. This judgment is made to confirm whether one of the parallel converter circuits is operating normally. Specifically, since the input power and the output power are approximately equal if the converter circuit is operating normally, the input power and the output power are compared to judge whether the difference between the input power and the output power is equal to or less than a predetermined value close to zero. If the power balances of both converter circuits are abnormal (step S507, Yes), the process proceeds to step S509. On the other hand, if only the power balance of one converter circuit is abnormal (step S507, No), the process proceeds to step S510.

[0053] (Step S508) The processing unit 100 determines that an abnormality has occurred in a plurality of DDCs. The plurality of DDCs are the auxiliary DDC 40 and the DDC whose input / output power balance has been determined to be abnormal in the above step S504. When the plurality of DDCs that have an abnormality are determined, the process proceeds to step S509.

[0054] (Step S509) The processing unit 100 determines that an abnormality occurs in both the first converter circuit (M11, M12, L1) and the second converter circuit (M21, M22, L2), and stops the auxiliary device DDC 40 to stop the solar charging system 1. This ends the abnormality control process of the second example.

[0055] (Step S510) Since one of the first converter circuit (M11, M12, L1) and the second converter circuit (M21, M22, L2) of the auxiliary DDC 40 is operating normally, the processing unit 100 continues the operation of the solar charging control as a system using this normally operating converter circuit (fail-safe processing). When the operation of the solar charging control is continued, the abnormality control processing of this second example ends.

[0056] By the above steps S501 to S510, when an abnormality occurs in the solar charging system 1, the DDC in which the abnormality (such as a sensor abnormality or a circuit abnormality) occurs can be accurately identified. Even if the current flowing in from the input side [G] of the auxiliary DDC 40 cannot be acquired, if the abnormality is only in one of the parallel converter circuits in the auxiliary DDC 40, the solar charging control operation by the system can be continued using a normal converter circuit. This control improves the operating rate of the auxiliary DDC 40 in the fail-safe process, and increases the reliability of the auxiliary DDC 40 and the system.

[0057] (3) Application Examples The abnormality control processing in the first and second examples described above is mainly for checking an abnormality in the auxiliary DDC40 in which the converter circuits are configured in parallel. However, the solar charging system 1 according to the present embodiment is configured with two panel power generation control units in parallel. Therefore, the same fail-safe processing as that of the converter circuit of the auxiliary DDC40 can be applied to the solar DDC21 and solar DDC22 in the parallel configuration. That is, when an abnormality in the power balance between input and output occurs in only one of the solar DDC21 and solar DDC22, it is possible to continuously supply power generated by one solar panel using the solar DDC operating normally. This fail-safe processing of the solar DDC is possible even when only one converter circuit is operating in the fail-safe processing of the auxiliary DDC40.

[0058] <Actions and Effects> As described above, according to the solar charging system 1 according to one embodiment of the present disclosure, when an abnormality occurs in the system, the DCDC converter in which the abnormality is occurring (location of the abnormality) can be accurately identified based on the power balance between the inputs and outputs of the solar DDC21, solar DDC22, high voltage DDC30, and auxiliary DDC40 and the power balance at the midpoint.

[0059] In addition, in the solar charging system 1 according to the present embodiment, when the auxiliary DDC 40 in which an abnormality has occurred is configured as a parallel configuration of converter circuits, the converter circuit in which an abnormality has occurred (one or both) can be identified based on the current deviation, which is the difference between the current output from the first converter circuit of the auxiliary DDC 40 and the current output from the second converter circuit, and the power balance between the input and output of the first converter circuit and the power balance between the input and output of the second converter circuit. Furthermore, when only one converter circuit in which an abnormality has occurred is present, the operation of the solar charging control by the system can be continued using a normal converter circuit, so that the availability of the auxiliary DDC 40 is increased and the reliability of the auxiliary DDC 40 and the system is improved.

[0060] The above describes one embodiment of the disclosed technology, but the present disclosure can be understood as not only a solar charging system, but also a method performed by a solar charging system, a program for that method, a computer-readable non-transitory storage medium storing the program, a vehicle equipped with a solar charging system, and the like. [Industrial Applicability]

[0061] The solar charging system of the present disclosure can be used in vehicles and the like that charge the battery using power generated by a solar panel. [Explanation of symbols]

[0062] 1 Solar charging system 11, 12 Solar panels 21, 22 Solar DDC (first DCDC converter) 30 High-voltage DDC (second DCDC converter) 40 Auxiliary DDC (3rd DCDC Converter) 41 Drive circuit 42 Input voltage sensor 44 Output voltage sensor 43 Input Current Sensor 45, 46 Output current sensor 50 High Voltage Battery 60 Auxiliary battery 70 Capacitor 100 Processing section M11, M12, M21, M22 switching elements L1, L2 inductors

Claims

1. A solar panel composed of multiple panels; A first power conversion device configured to receive the power generated by the solar panel and detect or derive the input power and the output power; a second power conversion device configured to receive the power output by the first power conversion device and to be capable of detecting or deriving the input power and the output power, The first power conversion device is composed of a plurality of first DC-DC converters respectively corresponding to the plurality of panels, The second power conversion device is a second DC-DC converter configured to be able to detect or derive input power and output power, and configured to output power input from the first power conversion device to a first battery; a third DC-DC converter configured to be able to detect or derive an output power and configured by connecting two or more converter circuits in parallel to output the power input from the first power conversion device to a second battery; A solar charging system further comprising a processing unit that, when an abnormality occurs in the system, determines whether an abnormality has occurred in at least the first DC-DC converter and the second DC-DC converter based on a comparison between the input power and output power of the first power conversion device and a comparison between the input power and output power of the second power conversion device, and determines whether an abnormality has occurred in the third DC-DC converter based on the differential value between each of two currents flowing through each of the converter circuits.

2. The solar charging system of claim 1, wherein when the processing unit determines that an abnormality has occurred in the third DC-DC converter, it identifies the location of the abnormality in the third DC-DC converter based on a comparison of the output power of the first DC-DC converter with the input power of the second DC-DC converter and the third DC-DC converter.

3. The solar charging system of claim 1, wherein when the processing unit determines that an abnormality has occurred in the third DC-DC converter, it identifies the location of the abnormality in the third DC-DC converter based on a comparison of the differential value between the output power of the first DC-DC converter and the input power of the second DC-DC converter with the output power of the third DC-DC converter.

4. a capacitor connected between the first power conversion device and the second power conversion device, The solar charging system of claim 2, wherein when the processing unit determines that an abnormality has occurred in the third DC-DC converter, it identifies the location of the abnormality in the third DC-DC converter based on a comparison of the output power of the first DC-DC converter and the discharge power of the capacitor with the input power of the second DC-DC converter and the third DC-DC converter and the charging power of the capacitor.

5. a capacitor connected between the first power conversion device and the second power conversion device, The solar charging system of claim 3, wherein when the processing unit determines that an abnormality has occurred in the third DC-DC converter, it identifies the location of the abnormality in the third DC-DC converter based on a comparison of the output power of the third DC-DC converter with the differential value between the output power of the first DC-DC converter and the discharge power of the capacitor and the input power of the second DC-DC converter and the charging power of the capacitor.

6. The solar charging system according to any one of claims 2 to 5, wherein when the processing unit determines that an abnormality has occurred in the third DC-DC converter, it identifies the converter circuit in which the abnormality has occurred based on a comparison between the input power and the output power of a first converter circuit, which is one of the converter circuits, and a comparison between the input power and the output power of a second converter circuit, which is one of the converter circuits.

7. 7. The solar charging system according to claim 6, wherein control is continued using the converter circuit in which no abnormality occurs.

8. A solar panel composed of a plurality of panels; a plurality of first DC-DC converters to which the power generated by the plurality of panels is input, respectively; a second DC-DC converter configured to be able to detect or derive input power and output power, and to output power input from the plurality of first DC-DC converters to a first battery; a third DC-DC converter configured to be able to detect or derive an output power and configured by connecting two or more converter circuits in parallel to output power input from the plurality of first DC-DC converters to a second battery, When an abnormality occurs in the system, determining whether an abnormality has occurred in at least the first DCDC converter and the second DCDC converter based on a comparison between the input power and the output power of the first DCDC converter and a comparison between the input power and the output power of the second DCDC converter; The method further comprises determining whether an abnormality has occurred in the third DCDC converter based on a difference value between each two of the currents flowing through each of the converter circuits.

9. A vehicle equipped with the solar charging system according to any one of claims 1 to 7.

Images