Electrical power supply circuit

Abstract

Disclosed is an electric power supply circuit. The electric power supply circuit (10) has: a load cable (48a) connecting a first battery (17a) and a first load (12a); a load cable (48b) connecting a second battery (17b) and a second load (12b); a transistor (54a) provided between a first generator (14a) and the load cable (48a); and a transistor (54b) provided between the first generator (14a) and the load cable (48b), the transistors (54a, 54b) being rendered non-conductive when electric power is supplied from the first generator (14a) to the first load (12a) and the second load (12b). Accordingly, even if electric power cannot be supplied to one of the two loads any more, electric power can be continued to be supplied to the other of the two loads.

Description

Technical Field

[0001] This invention relates to an electric power supply circuit. Background Technology

[0002] Japanese Patent Publication No. 2017-195651 discloses a system comprising a generator, a main battery, a secondary battery, a first switch unit, and a second switch unit. The generator supplies electrical power to a main load and a secondary load. The main battery supplies electrical power to the main load. The secondary battery supplies electrical power to the secondary load. The first switch unit is connected in parallel with a diode that allows current to flow from the generator to the main load. The second switch unit is also connected in parallel with a diode that allows current to flow from the generator to the secondary load. Summary of the Invention

[0003] In the aforementioned Japanese Patent Publication No. 2017-195651, the second switch is deactivated when the first switch is turned on. Conversely, the first switch is deactivated when the second switch is turned on. There is a concern that, for example, if a short circuit or other abnormality occurs in the conductive path connecting the secondary battery and the secondary load when the first switch is turned on, not only the secondary battery but also the main battery will discharge. Therefore, there is a problem that no power is supplied to either the main load or the secondary load.

[0004] The present invention was made to solve the above-mentioned technical problems. Its purpose is to provide an electrical power supply circuit (power supply circuit) that can continue to supply electrical power to the other of the two loads even if it is no longer possible to supply electrical power to one of the two loads.

[0005] The present invention provides an electrical power supply circuit, which includes a first conductive path, a second conductive path, and a generator. The first conductive path electrically connects a first energy storage unit and a first load; the second conductive path electrically connects a second energy storage unit and a second load; the generator supplies electrical power to the first load and the second load through the first and second conductive paths. The electrical power supply circuit includes a first element, a second element, a first switch, and a second switch. The first element is connected in series between the generator and the first conductive path, allowing current to flow from the generator side to the first conductive path side and restricting current flow from the first conductive path side to the generator side. The second element is connected in series. A first switch is connected between the generator and the second conductive path, allowing current to flow from the generator side to the second conductive path side and restricting current flow from the second conductive path side to the generator side; the first switch is connected in parallel with the first element, switching between a conducting state that electrically connects the generator and the first conductive path and a disconnecting state that electrically disconnects the generator and the first conductive path; the second switch is connected in parallel with the second element, switching between a conducting state that electrically connects the generator and the second conductive path and a disconnecting state that electrically disconnects the generator and the second conductive path, and disconnecting the first switch and the second switch when supplying electrical power from the generator to the first load and the second load.

[0006] According to the present invention, even if it is no longer possible to supply electrical power to one of the two loads, it is still possible to continue to supply electrical power to the other of the two loads.

[0007] The above-described objectives, features, and advantages should be readily understood from the following description of the embodiments with reference to the accompanying drawings. Attached Figure Description

[0008] Figure 1 This is a circuit diagram of an electrical power supply circuit.

[0009] Figure 2 It is a diagram that schematically illustrates the connection relationship of the power supply circuit.

[0010] Figure 3 It is a diagram that schematically illustrates the connection relationship of the power supply circuit.

[0011] Figure 4 It is a diagram that schematically illustrates the connection relationship of the power supply circuit.

[0012] Figure 5 It is a diagram that schematically illustrates the connection relationship of the power supply circuit.

[0013] Figure 6 It is a diagram that schematically illustrates the connection relationship of the power supply circuit.

[0014] Figure 7 It is a diagram that schematically illustrates the connection relationship of the power supply circuit. Detailed Implementation

[0015] [First Embodiment]

[0016] Figure 1 This is a circuit diagram of the power supply circuit 10 of this embodiment. The power supply circuit 10 supplies power to three loads: the first load 12a, the second load 12b, and the third load 12c. Hereinafter, without specifically distinguishing between the first load 12a, the second load 12b, and the third load 12c, they will be referred to as load 12.

[0017] The power supply circuit 10 includes a power control unit 16, a first intelligent power unit 18a, a second intelligent power unit 18b, and a third intelligent power unit 18c. Hereinafter, the power control unit will sometimes be referred to as a PCU. Hereinafter, the intelligent power unit will sometimes be referred to as an IPU.

[0018] PCU16 has a first generator 14a and a second generator 14b as power sources. Hereinafter, without special distinction between the first generator 14a and the second generator 14b, they will be referred to as generator 14. First IPU18a has a first battery 17a as power source. Second IPU18b has a second battery 17b as power source. Third IPU18c has a third battery 17c as power source. Hereinafter, without special distinction between the first battery 17a, the second battery 17b, and the third battery 17c, they will be referred to as battery 17.

[0019] The first load 12a has an internal capacitor 20a. The second load 12b has an internal capacitor 20b. The third load 12c has an internal capacitor 20c. The first load 12a corresponds to the first load of the present invention. The second load 12b corresponds to the second load of the present invention.

[0020] The first generator 14a has an internal capacitor 22a. The second generator 14b has an internal capacitor 22b. The first generator 14a has a protection device 24a. The protection device 24a stops the first generator 14a when an overcurrent is detected. The second generator 14b has a protection device 24b. The protection device 24b stops the second generator 14b when an overcurrent is detected. The first generator 14a corresponds to the generator of the present invention.

[0021] Generator 14a is connected to the first common bus 27a via PCU bus 26aa and to the second common bus 27b via PCU bus 26ab. Generator 14b is connected to the first common bus 27a via PCU bus 26ba and to the second common bus 27b via PCU bus 26bb. Generators 14a and 14b are connected in parallel via the first common bus 27a. Generators 14a and 14b are also connected in parallel via the second common bus 27b. PCU buses 26aa, 26ab, 26ba, and 26bb can also be multiplexed.

[0022] A PCU fuse 28aa and a PCU switch 30aa are installed on the positive terminal wiring connecting the first generator 14a and the PCU bus 26aa. The PCU fuse 28aa and the PCU switch 30aa are connected in series. A PCU switch 31aa is installed on the negative terminal wiring connecting the first generator 14aa and the PCU bus 26aa. Alternatively, only one of the PCU switches 30aa and 31aa may be installed.

[0023] A PCU fuse 28ab and a PCU switch 30ab are installed on the positive terminal wiring connecting the first generator 14a and the PCU bus 26ab. The PCU fuse 28ab and the PCU switch 30ab are connected in series. A PCU switch 31ab is installed on the negative terminal wiring connecting the first generator 14a and the PCU bus 26ab. Alternatively, only one of the PCU switches 30ab and 31ab may be installed.

[0024] A PCU fuse 28ba and a PCU switch 30ba are installed on the positive wiring connecting the second generator 14b and the PCU bus 26ba. The PCU fuse 28ba and the PCU switch 30ba are connected in series. A PCU switch 31ba is installed on the negative wiring connecting the second generator 14b and the PCU bus 26ba. Alternatively, only one of the PCU switches 30ba and 31ba may be installed.

[0025] A PCU fuse 28bb and a PCU switch 30bb are installed on the positive wiring connecting the second generator 14b and the PCU bus 26bb. The PCU fuse 28bb and the PCU switch 30bb are connected in series. A PCU switch 31bb is installed on the negative wiring connecting the second generator 14b and the PCU bus 26bb. Alternatively, only one of the PCU switches 30bb and 31bb may be installed.

[0026] The first common bus 27a is connected to the first IPU 18a via IPU bus 32aa, to the second IPU 18b via IPU bus 32ab, and to the third IPU 18c via IPU bus 32ac. The second common bus 27b is connected to the first IPU 18a via IPU bus 32ba, to the second IPU 18b via IPU bus 32bb, and to the third IPU 18c via IPU bus 32bc. IPU buses 32aa, 32ab, 32ac, 32ba, 32bb, and 32bc can also be multiplexed individually.

[0027] A common bus switch 33aa is provided on the positive wiring connecting the first common bus 27a and the IPU bus 32aa. A common bus switch 34aa is provided on the negative wiring connecting the first common bus 27a and the IPU bus 32aa. Alternatively, only one of the common bus switches 33aa and 34aa may be provided.

[0028] A common bus switch 33ab is provided on the positive wiring connecting the first common bus 27a and the IPU bus 32ab. A common bus switch 34ab is provided on the negative wiring connecting the first common bus 27a and the IPU bus 32ab. Alternatively, only one of the common bus switches 33ab and 34ab may be provided.

[0029] A common bus switch 33ac is provided on the positive wiring connecting the first common bus 27a and the IPU bus 32ac. A common bus switch 34ac is provided on the negative wiring connecting the first common bus 27a and the IPU bus 32ac. Alternatively, only one of the common bus switches 33ac and 34ac may be provided.

[0030] A common bus switch 33ba is provided on the positive wiring connecting the second common bus 27b and the IPU bus 32ba. A common bus switch 34ba is provided on the negative wiring connecting the second common bus 27b and the IPU bus 32ba. Alternatively, only one of the common bus switches 33ba and 34ba may be provided.

[0031] A common bus switch 33bb is provided on the positive wiring connecting the second common bus 27b and the IPU bus 32bb. A common bus switch 34bb is provided on the negative wiring connecting the second common bus 27b and the IPU bus 32bb. Alternatively, only one of the common bus switches 33bb and 34bb may be provided.

[0032] A common bus switch 33bc is provided on the positive wiring connecting the second common bus 27b and the IPU bus 32bc. A common bus switch 34bc is provided on the negative wiring connecting the second common bus 27b and the IPU bus 32bc. Alternatively, only one of the common bus switches 33bc and 34bc may be provided.

[0033] An IPU fuse 36a is installed on the negative terminal wiring connecting IPU 18a, IPU bus 32aa, and IPU bus 32ba. An IPU fuse 36b is installed on the negative terminal wiring connecting IPU 18b, IPU bus 32ab, and IPU bus 32bb. An IPU fuse 36c is installed on the negative terminal wiring connecting IPU 18c, IPU bus 32ac, and IPU bus 32bc.

[0034] The first battery 17a is connected in parallel with both the first generator 14a and the second generator 14b. The second battery 17b is connected in parallel with both the first generator 14a and the second generator 14b. The third battery 17c is connected in parallel with both the first generator 14a and the second generator 14b. The first battery 17a corresponds to the first energy storage unit of the present invention. The second battery 17b corresponds to the second energy storage unit of the present invention.

[0035] A battery fuse 38a and a battery switch 40a are connected to the positive terminal of the first battery 17a. The battery fuse 38a and the battery switch 40a are connected in series. A battery fuse 38b and a battery switch 40b are connected to the positive terminal of the second battery 17b. The battery fuse 38b and the battery switch 40b are connected in series. A battery fuse 38c and a battery switch 40c are connected to the positive terminal of the third battery 17c. The battery fuse 38c and the battery switch 40c are connected in series.

[0036] A battery switch 41a is connected to the negative terminal of the first battery 17a. A pre-charge circuit 42a is connected in parallel with the battery switch 41a. The pre-charge circuit 42a has a resistor 44a and a pre-charge switch 46a. The resistor 44a and the pre-charge switch 46a are connected in series. A battery switch 41b is connected to the negative terminal of the second battery 17b. A pre-charge circuit 42b is connected in parallel with the battery switch 41b. The pre-charge circuit 42b has a resistor 44b and a pre-charge switch 46b. The resistor 44b and the pre-charge switch 46b are connected in series. A battery switch 41c is connected to the negative terminal of the third battery 17c. A pre-charge circuit 42c is connected in parallel with the battery switch 41c. The pre-charge circuit 42c has a resistor 44c and a pre-charge switch 46c. The resistor 44c and the pre-charge switch 46c are connected in series.

[0037] IPU18a is electrically connected to load 12a via load cable 48a. IPU18b is electrically connected to load 12b via load cable 48b. IPU18c is electrically connected to load 12c via load cable 48c. Hereinafter, without special distinction between load cables 48a, 48b, and 48c, they will be referred to as load cable 48.

[0038] A load fuse 50a is provided on the positive terminal wire connecting the first IPU 18a and the load cable 48a. A load fuse 50b is provided on the positive terminal wire connecting the second IPU 18b and the load cable 48b. A load fuse 50c is provided on the positive terminal wire connecting the third IPU 18c and the load cable 48c. The load cable 48a corresponds to the first conductive path of the present invention. The load cable 48b corresponds to the second conductive path of the present invention.

[0039] The electrical power generated by the first generator 14a and the second generator 14b is supplied to the first load 12a via load cable 48a. The electrical power generated by the first generator 14a and the second generator 14b is supplied to the second load 12b via load cable 48b. The electrical power generated by the first generator 14a and the second generator 14b is supplied to the third load 12c via load cable 48c. Load cable 48 can also be multiplexed.

[0040] A diode 52a is provided on the positive terminal wiring connecting the first IPU 18a and IPU buses 32aa and 32ba. Diode 52a allows current to flow from the first generator 14a and the second generator 14b to the load cable 48a. Conversely, diode 52a restricts current flow from the load cable 48a to the first generator 14a and the second generator 14b. Diode 52a corresponds to the first element of the present invention.

[0041] A diode 52b is provided on the positive terminal wiring connecting the second IPU 18b and IPU buses 32ab and 32bb. Diode 52b allows current to flow from the first generator 14a and the second generator 14b to the load cable 48b. Conversely, diode 52b restricts current flow from the load cable 48b to the first generator 14a and the second generator 14b. Diode 52b corresponds to the second element of the present invention.

[0042] A diode 52c is provided on the positive terminal wiring connecting the third IPU 18c and IPU buses 32ac and 32bc. Diode 52c allows current to flow from the first generator 14a and the second generator 14b to the load cable 48c. Conversely, diode 52c restricts current flow from the load cable 48c to the first generator 14a and the second generator 14b.

[0043] A transistor 54a is arranged in parallel with diode 52a. When transistor 54a is turned on, the first generator 14a, the second generator 14b, and the load cable 48a are electrically connected bypassing diode 52a. The switching of transistor 54a on and off is controlled by base current or gate voltage. Transistor 54a is equivalent to the first switch of the present invention.

[0044] A transistor 54b is arranged in parallel with diode 52b. When transistor 54b is turned on, the first generator 14a, the second generator 14b, and the load cable 48b are electrically connected bypassing diode 52b. The switching of transistor 54b between on and off is controlled by base current or gate voltage. Transistor 54b is equivalent to the second switch of the present invention.

[0045] A transistor 54c is arranged in parallel with diode 52c. When transistor 54c is turned on, the first generator 14a, the second generator 14b, and the load cable 48c are electrically connected bypassing diode 52c. The switching of transistor 54c between on and off is controlled by base current or gate voltage.

[0046] A pre-charge circuit can also be provided in parallel with transistor 54a. When the capacitor 22a of the first generator 14a and the capacitor 22b of the second generator 14b are charged by the electrical power of the first battery 17a, electrical power is supplied to capacitors 22a and 22b via this pre-charge circuit. This prevents inrush current during the charging of capacitors 22a and 22b.

[0047] A pre-charge circuit can also be provided in parallel with transistor 54b. When the capacitors 22a of the first generator 14a and 22b of the second generator 14b are charged by the electrical power from the second battery 17b, electrical power is supplied to capacitors 22a and 22b via this pre-charge circuit. This prevents inrush current during the charging of capacitors 22a and 22b.

[0048] A pre-charge circuit can also be configured in parallel with transistor 54c. When the capacitor 22a of the first generator 14a and the capacitor 22b of the second generator 14b are charged by the electrical power of the third battery 17c, electrical power is supplied to capacitors 22a and 22b via this pre-charge circuit. This prevents inrush current during the charging of capacitors 22a and 22b.

[0049] In the power supply circuit 10 described above, PCU16 has a first generator 14a and a second generator 14b. That is, PCU16 has two generators. In contrast, PCU16 may also have three or more generators.

[0050] Furthermore, the power supply circuit 10 described above has a first IPU 18a, a second IPU 18b, and a third IPU 18c. That is, the power supply circuit 10 has three IPUs. In contrast, the power supply circuit 10 may also have two or more IPUs.

[0051] Alternatively, a large-capacity capacitor can be used instead of the first battery 17a, the second battery 17b, and the third battery 17c.

[0052] The power supply circuit 10 has an arithmetic unit and a decision unit (not shown). In addition to controlling transistors 54a, 54b, and 54c, the power supply circuit 10 also controls each switch. The arithmetic unit and the decision unit can be implemented, for example, by a processing circuit.

[0053] The processing circuit can be constructed from integrated circuits such as ASICs (Application Specific Integrated Circuits) and FPGAs (Field-Programmable Gate Arrays). Alternatively, the processing circuit can also be constructed from electronic circuits that include discrete components.

[0054] Alternatively, the processing circuit can be constructed using a processor such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit). In this case, the processing circuit can be implemented by executing a program stored in memory (not shown) through the processor.

[0055] [Regarding transistor operation]

[0056] The operation of transistors 54a, 54b, and 54c corresponding to the states of the power supply circuit 10 will now be described. For simplicity, the connection relationships of the first battery 17a, the second battery 17b, the first generator 14a, the first load 12a, and the second load 12b will be schematically represented. Figures 2-7 Let me explain. Figures 2-7 In this diagram, the circuit structure other than PCU bus 26aa, battery fuses 38a and 38b, load cables 48a and 48b, load fuses 50a and 50b, diodes 52a and 52b, and transistors 54a and 54b are omitted.

[0057] The following description of the operation of the second generator 14b, the third battery 17c, and the transistor 54c is omitted. The operation of the second generator 14b, the third battery 17c, and the transistor 54c is the same as that of the first generator 14a, the first battery 17a, the second battery 17b, and the transistors 54a and 54b.

[0058] (Starting the generator)

[0059] The operation of transistors 54a and 54b is described when the first generator 14a is started by the electrical power of the first battery 17a and the second battery 17b. Figure 2 This is a schematic diagram of the power supply circuit 10.

[0060] In this configuration, the power supply circuit 10 turns on transistors 54a and 54b. Accordingly, power is supplied from the first battery 17a to the first generator 14a via transistor 54a. Additionally, power is supplied from the second battery 17b to the first generator 14a via transistor 54b. The first generator 14a is activated by the power supplied from the first battery 17a and the second battery 17b.

[0061] When the first generator 14a is started, it is also possible to turn on only one of transistors 54a and 54b, while turning off the other. In this case, the first generator 14a is started by electrical power supplied from either the first battery 17a or the second battery 17b.

[0062] (Supplying electrical power to the load)

[0063] The operation of transistors 54a and 54b when supplying electrical power from the first generator 14a to the first load 12a and the second load 12b will be described. Figure 3 This is a schematic diagram of the power supply circuit 10.

[0064] In this configuration, the power supply circuit 10 turns off transistors 54a and 54b. Accordingly, power is supplied from the first generator 14a to the first load 12a via diode 52a. Additionally, power is also supplied from the first battery 17a to the first load 12a. The first load 12a is driven by the power supplied from the first generator 14a and the first battery 17a.

[0065] Furthermore, electrical power is supplied from the first generator 14a to the second load 12b via diode 52b. Additionally, electrical power is also supplied from the second battery 17b to the second load 12b. The second load 12b is driven by the electrical power supplied from the first generator 14a and the second battery 17b. Furthermore, current does not flow from either the first battery 17a or the second battery 17b to the first generator 14a.

[0066] (Power supply to the load in case of abnormality in the power supply circuit (1))

[0067] The operation of transistors 54a and 54b in the event of an abnormality in the power supply circuit 10 is explained. Figure 4 This is a schematic diagram of the power supply circuit 10.

[0068] An abnormality in the power supply circuit 10 refers to, for example, Figure 4 The diagram illustrates a short circuit between the positive and negative terminals of the load cable 48a. For example, in the event of a short circuit in the load cable 48a, both the battery fuse 38a and the load fuse 50a trip. Additionally, the protection device 24a detects an overcurrent. Therefore, the protection device 24a stops the first generator 14a. At this time, since the transistor 54b is turned off, current does not flow from the second battery 17b to the load cable 48a. Therefore, power is maintained from the second battery 17b to the second load 12b.

[0069] An abnormality in the power supply circuit 10 could occur, for example, if the positive and negative terminals of the load cable 48b are short-circuited. When the load cable 48b is short-circuited, the battery fuse 38b and the load fuse 50b trip. Additionally, the protection device 24a detects an overcurrent. Therefore, the protection device 24a stops the first generator 14a. At this time, since the transistor 54a is turned off, current does not flow from the first battery 17a to the load cable 48b. Therefore, power is maintained from the first battery 17a to the first load 12a.

[0070] An abnormality in the power supply circuit 10 refers to a short circuit between the positive and negative terminals of the PCU bus 26aa. In the event of a short circuit in the PCU bus 26aa, the protection device 24a detects an overcurrent. Therefore, the protection device 24a stops the first generator 14a. At this time, since transistors 54a and 54b are turned off, current does not flow from the first battery 17a and the second battery 17b to the PCU bus 26aa side. Therefore, power is maintained from the first battery 17a to the first load 12a and from the second battery 17b to the second load 12b.

[0071] (Restarting the generator)

[0072] The operation of transistors 54a and 54b when the first generator 14a is restarted is explained. Figure 5 This is a schematic diagram of the power supply circuit 10.

[0073] For example, such as Figure 5As shown, when the first generator 14a is restarted while the load cable 48a is short-circuited, the power supply circuit 10 turns on transistor 54b while keeping transistor 54a off. The time at which transistor 54b is turned on is determined to be the time after the load fuse 50a has blown. For example, the condition that the load fuse 50a has blown can be determined by monitoring the current flowing to the first load 12a using a current sensor. At this time, since transistor 54a is off, current does not flow from the second battery 17b to the load cable 48a. Therefore, power is supplied from the second battery 17b to the first generator 14a via transistor 54b. The first generator 14a starts using the power supplied from the second battery 17b.

[0074] For example, when restarting the first generator 14a while the load cable 48b is short-circuited, the power supply circuit 10 turns on transistor 54a while keeping transistor 54b off. The time at which transistor 54a is turned on is determined to be the point in time after the load fuse 50b has blown. For example, the condition that the load fuse 50b has blown can be determined by monitoring the current flowing to the second load 12b using a current sensor. At this time, since transistor 54b is off, current does not flow from the first battery 17a to the load cable 48a. Therefore, power is supplied from the first battery 17a to the first generator 14a via transistor 54a. The first generator 14a starts using the power supplied from the first battery 17a.

[0075] For example, in the event of a short circuit on PCU bus 26aa, the power supply circuit 10 keeps transistors 54a and 54b off. At this time, the power supply circuit 10 cannot restart the first generator 14a. Therefore, the first load 12a is driven by the power supplied from the first battery 17a. Additionally, the second load 12b is driven by the power supplied from the second battery 17b.

[0076] (Power supply to the load in the event of an abnormality in the power supply circuit (2))

[0077] The operation of transistors 54a and 54b in the event of an abnormality in the power supply circuit 10 is explained. Figure 6 This is a schematic diagram of the power supply circuit 10.

[0078] For example, such as Figure 6As shown, when the first generator 14a is restarted with the load cable 48a short-circuited, the power supply circuit 10 cuts off transistors 54a and 54b. At this time, since the load fuse 50a is open, current does not flow from the first generator 14a to the load cable 48a. On the other hand, power is supplied from the first generator 14a to the second load 12b via diode 52b. Additionally, power is supplied from the second battery 17b to the second load 12b. The second load 12b is driven by the power supplied from the first generator 14a and the second battery 17b.

[0079] Furthermore, when the first generator 14a is restarted while the load cable 48b is short-circuited, the power supply circuit 10 cuts off transistors 54a and 54b. At this time, since the load fuse 50b is open, current does not flow from the first generator 14a to the load cable 48b. On the other hand, power is supplied from the first generator 14a to the first load 12a via diode 52a. Additionally, power is supplied from the first battery 17a to the first load 12a. The first load 12a is driven by the power supplied from the first generator 14a and the first battery 17a.

[0080] (Power supply to the load in case of battery malfunction)

[0081] The operation of transistors 54a and 54b in the event of an abnormality in either the first battery 17a or the second battery 17b is described. Figure 7 This is a schematic diagram of the power supply circuit 10.

[0082] An abnormality in the first battery 17a could refer to a short circuit between the positive and negative terminals inside the first battery 17a. Figure 7 As shown, when the first battery 17a is short-circuited, the power supply circuit 10 turns on transistor 54b while keeping transistor 54a off. The time at which transistor 54b is turned on is determined to be the time after the battery fuse 38a has blown. For example, the condition that the battery fuse 38a has blown can be determined by monitoring the current flowing to the first battery 17a using a current sensor. At this time, since the battery fuse 38a is blown, current does not flow from the first generator 14a and the second battery 17b to the first battery 17a.

[0083] As a result, electrical power is supplied from the first generator 14a to the first load 12a via diode 52a. Electrical power is also supplied from the second battery 17b to the first load 12a via transistor 54b and diode 52a. The first load 12a is driven by the electrical power supplied from the first generator 14a and the second battery 17b.

[0084] Additionally, electrical power is supplied from the first generator 14a to the second load 12b via transistor 54b. Electrical power is also supplied from the second battery 17b to the second load 12b. The second load 12b is driven by the electrical power supplied from the first generator 14a and the second battery 17b.

[0085] An abnormality in battery 17b refers to, for example, a short circuit between the positive and negative terminals inside the second battery 17b. In the event of a short circuit in the second battery 17b, the power supply circuit 10 turns on transistor 54a while keeping transistor 54b off. The time at which transistor 54a is turned on is determined to be after the battery fuse 38b has blown. For example, the blown battery fuse 38b can be determined by monitoring the current flowing to the second battery 17b using a current sensor. At this time, because the battery fuse 38b is blown, current does not flow from the first generator 14a and the second battery 17b to the second battery 17b.

[0086] As a result, electrical power is supplied from the first generator 14a to the second load 12b via diode 52b. Electrical power is also supplied from the first battery 17a to the second load 12b via transistor 54a and diode 52b. The second load 12b is driven by the electrical power supplied from the first generator 14a and the first battery 17a.

[0087] Additionally, electrical power is supplied from the first generator 14a to the first load 12a via transistor 54a. Electrical power is also supplied from the first battery 17a to the first load 12a. The first load 12a is driven by the electrical power supplied from the first generator 14a and the first battery 17a.

[0088] [Effects]

[0089] In this embodiment, the power supply circuit 10 is configured such that, for fault protection, multiple generators (first generator 14a and second generator 14b) supply power to all loads (first load 12a, second load 12b, and third load 12c), respectively. Therefore, even if some generators malfunction, the power supply from the other generators can be maintained.

[0090] Furthermore, in the power supply circuit 10 of this embodiment, batteries (first battery 17a, second battery 17b, and third battery 17c) are provided as dedicated power sources for each of the multiple loads (first load 12a, second load 12b, and third load 12c). Each load is pre-charged using the power of each battery. In the event of a failure of the first generator 14a and the second generator 14b, each load operates using the power of its respective battery. Additionally, the generator is started using the power of each battery.

[0091] Even in the event of an abnormality such as a short circuit in the conductive path that supplies power to a portion of the load, the power supply circuit 10 must continue to supply power to the other loads.

[0092] Therefore, the power supply circuit 10 of this embodiment has diodes 52a, 52b, and 52c between the generator 14 and the load cable 48. Diodes 52a, 52b, and 52c allow current to flow from the generator 14 to the load cable 48. On the other hand, diodes 52a, 52b, and 52c restrict current flow from the load cable 48 to the generator 14. Furthermore, the power supply circuit 10 of this embodiment has transistors 54a, 54b, and 54c connected in parallel with each of the diodes 52a, 52b, and 52c. Moreover, when power is supplied from the generator 14 to the load 12, transistors 54a, 54b, and 54c are turned off.

[0093] Therefore, for example, even in the event of a short circuit in the load cable 48a, there will be no leakage of current from the second battery 17b and the third battery 17c to the load cable 48a. Thus, power is maintained from the second battery 17b to the second load 12b. And power is maintained from the third battery 17c to the third load 12c.

[0094] In this embodiment, the power supply circuit 10 turns on transistor 54a when supplying power from the first battery 17a to the first generator 14a or the second generator 14b. Additionally, the power supply circuit 10 turns on transistor 54b when supplying power from the second battery 17b to the first generator 14a or the second generator 14b. The power supply circuit 10 also turns on transistor 54c when supplying power from the third battery 17c to the first generator 14a or the second generator 14b.

[0095] Accordingly, electrical power can be supplied from the first battery 17a, the second battery 17b, and the third battery 17c to the first generator 14a and the second generator 14b, respectively. Therefore, the first generator 14a and the second generator 14b can be started.

[0096] In this embodiment, when the load cable 48a is short-circuited, the power supply circuit 10 turns on transistors 54b and 54c after determining that the load fuse 50a has blown. This allows power to be supplied from the second battery 17b and the third battery 17c to the first generator 14a and the second generator 14b. Therefore, the first generator 14a and the second generator 14b can be restarted. Furthermore, while the first generator 14a and the second generator 14b are in a stopped state, power can be continuously supplied from the second battery 17b to the second load 12b. While the first generator 14a and the second generator 14b are in a stopped state, power can be continuously supplied from the third battery 17c to the third load 12c.

[0097] Similarly, in the event of a short circuit in the load cable 48b, the power supply circuit 10 of this embodiment turns on transistors 54a and 54c after determining that the load fuse 50b has blown. Accordingly, power can be supplied from the first battery 17a and the third battery 17c to the first generator 14a and the second generator 14b. Therefore, the first generator 14a and the second generator 14b can be restarted. Furthermore, while the first generator 14a and the second generator 14b are in a stopped state, power can be continuously supplied from the first battery 17a to the first load 12a. While the first generator 14a and the second generator 14b are in a stopped state, power can be continuously supplied from the third battery 17c to the third load 12c.

[0098] Furthermore, in the event of a short circuit in the load cable 48c, the power supply circuit 10 of this embodiment turns on transistors 54a and 54b after determining that the load fuse 50c has blown. Accordingly, power can be supplied from the first battery 17a and the second battery 17b to the first generator 14a and the second generator 14b. Therefore, the first generator 14a and the second generator 14b can be restarted. Additionally, while the first generator 14a and the second generator 14b are in a stopped state, power can be continuously supplied from the first battery 17a to the first load 12a. While the first generator 14a and the second generator 14b are in a stopped state, power can be continuously supplied from the second battery 17b to the second load 12b.

[0099] Battery 17 needs to provide enough electrical energy to drive load 12 from the time generator 14 stops until it restarts, and enough electrical energy to restart generator 14. Therefore, the power capacity of each of the first battery 17a, the second battery 17b, and the third battery 17c can be reduced. As a result, the size of each of the first battery 17a, the second battery 17b, and the third battery 17c can be reduced.

[0100] [Technical ideas that can be obtained from the implementation methods]

[0101] The following describes the technical concepts that can be grasped based on the above implementation methods.

[0102] An electrical power supply circuit has a first conductive path (48a), a second conductive path (48b), and a generator (14a). The first conductive path (48a) electrically connects a first energy storage unit (17a) and a first load (12a); the second conductive path (48b) electrically connects a second energy storage unit (17b) and a second load (12b); the generator (14a) supplies electrical power to the first load and the second load through the first and second conductive paths. The electrical power supply circuit has a first element (52a), a second element (52b), a first switch (54a), and a second switch (54b), wherein the first element (52a) is connected in series between the generator and the first conductive path, allowing current to flow from the generator side to the first conductive path side and restricting current from the generator side to the first conductive path side. A conductive path flows towards the generator side. The second element (52b) is connected in series between the generator and the second conductive path, allowing current to flow from the generator side to the second conductive path side and restricting current flow from the second conductive path side to the generator side. The first switch (54a) is connected in parallel with the first element and switches between a conducting state that electrically connects the generator and the first conductive path and a disconnecting state that electrically disconnects the generator and the first conductive path. The second switch (54b) is connected in parallel with the second element and switches between a conducting state that electrically connects the generator and the second conductive path and a disconnecting state that electrically disconnects the generator and the second conductive path. When power is supplied from the generator to the first load and the second load, the first switch and the second switch are disconnected.

[0103] In the above-described power supply circuit, the first switch can be turned on when power is supplied from the first energy storage unit to the generator, and the second switch can be turned on when power is supplied from the second energy storage unit to the generator.

[0104] In the above-described power supply circuit, the generator may also have a protection device (24a). The protection device (24a) stops the operation of the generator when an overcurrent is detected. When the first conductive path is abnormal, the second switch is turned on to supply power to the generator from the second energy storage unit. When the second conductive path is abnormal, the first switch is turned on to supply power to the generator from the first energy storage unit.

[0105] In the above-described power supply circuit, when the first conductive path malfunctions, the second switch is turned on after the generator and the first conductive path are electrically disconnected, and power is supplied from the second energy storage unit to the generator. When the second conductive path malfunctions, the first switch is turned on after the generator and the second conductive path are electrically disconnected, and power is supplied from the first energy storage unit to the generator.

[0106] In the aforementioned power supply circuit, when the first energy storage unit malfunctions, after the first energy storage unit is electrically disconnected from the first element, the second switch is turned on to supply power from the second energy storage unit to the first load. When the second energy storage unit malfunctions, after the second energy storage unit is electrically disconnected from the second element, the first switch is turned on to supply power from the first energy storage unit to the second load.

Claims

1. An electrical power supply circuit having a first conductive path (48a), a second conductive path (48b), and a generator (14a), wherein, The first conductive path (48a) electrically connects the first energy storage unit (17a) and the first load (12a); The second conductive path (48b) electrically connects the second energy storage unit (17b) and the second load (12b); The generator (14a) supplies electrical power to the first load and the second load through the first conductive path and the second conductive path. Its features are, It includes a first element (52a), a second element (52b), a first switch (54a), a second switch (54b), and a protection device (24a), wherein, The first element (52a) is connected in series between the generator and the first conductive path, allowing current to flow from the generator side to the first conductive path side and restricting current flow from the first conductive path side to the generator side. The second element (52b) is connected in series between the generator and the second conductive path, allowing current to flow from the generator side to the second conductive path side and restricting current flow from the second conductive path side to the generator side; The first switch (54a) is connected in parallel with the first element and is used to switch between a conducting state that electrically connects the generator and the first conductive path and a disconnecting state that electrically disconnects the generator and the first conductive path. The second switch (54b) is connected in parallel with the second element and is used to switch between a conducting state that electrically connects the generator and the second conductive path and a disconnecting state that electrically disconnects the generator and the second conductive path. The protection device (24a) stops the generator from operating when it detects an overcurrent. When supplying electrical power from the generator to the first load and the second load, the first switch and the second switch are disconnected. When the first conductive path malfunctions, after the generator is stopped by the protection device, the second switch is turned on, supplying electrical power from the second energy storage unit to the generator. When the second conductive path malfunctions, the first switch is turned on after the generator is stopped by the protection device, and electrical power is supplied from the first energy storage unit to the generator.

2. The power supply circuit according to claim 1, characterized in that, The first switch is turned on when electrical power is supplied from the first energy storage unit to the generator. The second switch is turned on when electrical power is supplied from the second energy storage unit to the generator. The generator is started by simultaneously turning on the first switch and the second switch.

3. The power supply circuit according to claim 1, characterized in that, It has a first fuse and a second fuse, wherein, The first fuse is disposed between the first energy storage unit and the first conductive path, and is also disposed between the generator and the first conductive path. The second fuse is disposed between the second energy storage unit and the second conductive path, and is also disposed between the generator and the second conductive path. When the first conductive path malfunctions, after the first fuse electrically disconnects the generator from the first conductive path, the second switch is turned on while the first switch remains open, supplying electrical power from the second energy storage unit to the generator. When the second conductive path malfunctions, after the second fuse electrically disconnects the generator from the second conductive path, the first switch is turned on while the second switch remains open, so that electrical power is supplied from the first energy storage unit to the generator.

4. The power supply circuit according to any one of claims 1 to 3, characterized in that, It has a third fuse and a fourth fuse, wherein, The third fuse is disposed between the first energy storage unit and the first conductive path, between the first energy storage unit and the first element, and between the first energy storage unit and the first switch. The fourth fuse is disposed between the second energy storage unit and the second conductive path, between the second energy storage unit and the second element, and between the second energy storage unit and the second switch. When the first energy storage unit malfunctions, the second switch is turned on after the third fuse electrically disconnects the connection between the first energy storage unit and the first element, allowing electrical power to be supplied from the second energy storage unit to the first load. When the second energy storage unit malfunctions, the first switch is turned on after the fourth fuse electrically disconnects the connection between the second energy storage unit and the second element, thereby supplying electrical power from the first energy storage unit to the second load.

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