Electric motor car

Abstract

To avoid a short circuit of a battery due to an erroneous operation of a relay in a power supply device.SOLUTION: A power supply device comprises: a first battery; a second battery; a first relay that electrically connects and disconnects between a positive electrode of the first battery and a positive electrode of the second battery; a second relay that electrically connects and disconnects between a negative electrode of the first battery and the positive electrode of the second battery; a third relay that electrically connects and disconnects between the negative electrode of the first battery and the negative electrode of the second battery; and a control device that controls operations of the first, second, and third relays. The control device comprises: at least one processor; a first AND gate element; and a second AND gate element. The first and second AND gate elements are configured to drive the corresponding relay in response to a combination of a drive signal and an enable signal.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The technology disclosed in this specification relates to a power supply device.

Background Art

[0002] Patent Document 1 discloses a power supply device. This power supply device includes a first battery, a second battery, and a plurality of relays. The plurality of relays include a first relay that electrically connects and disconnects between the positive electrode of the first battery and the negative electrode of the second battery, a second relay that electrically connects and disconnects between the positive electrode of the first battery and the positive electrode of the second battery, and a third relay that electrically connects and disconnects between the negative electrode of the first battery and the negative electrode of the second battery.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the power supply device as described above, with the second relay off (i.e., open), by turning on the first relay and the third relay (i.e., closed), the two batteries can be connected in parallel. Also, with the first relay and the third relay off, by turning on the second relay, the two batteries can be connected in series. On the other hand, if at least one of the first relay and the third relay and the second relay are turned on simultaneously, there is a concern that the poles of the first battery and / or the second battery will be short-circuited. This specification provides a technology for avoiding such a short circuit.

Means for Solving the Problems

[0005] The technology disclosed in this specification is embodied in a power supply device. This power supply device includes a first battery, a second battery, a first relay for electrically connecting and disconnecting between the positive electrode of the first battery and the positive electrode of the second battery, a second relay for electrically connecting and disconnecting between the negative electrode of the first battery and the positive electrode of the second battery, a third relay for electrically connecting and disconnecting between the negative electrode of the first battery and the negative electrode of the second battery, and a control device for controlling the operations of the first relay, the second relay, and the third relay. The control device has at least one processor, a first AND gate element, and a second AND gate element. The at least one processor is configured to output a first drive signal for the first relay and the third relay, a second drive signal for the second relay, and at least one permission signal. The at least one permission signal includes at least one of a first permission signal for permitting the first relay and the third relay to be turned on and a second permission signal for permitting the second relay to be turned on. The first AND gate element is configured to further receive, in addition to the first drive signal, one of the first permission signal or the inverted signal of the second permission signal, and output their AND signal to the first relay and the third relay. The second AND gate element is configured to further receive, in addition to the second drive signal, one of the inverted signal of the first permission signal or the second permission signal, and output their AND signal to the second relay.

[0006] According to the above configuration, each relay of the power supply device is not driven (especially turned on) only by the first drive signal or the second drive signal, but is driven only by a combination with the permission signal. Thereby, unintentional driving of each relay is prevented, and in the first battery and the second battery, it is possible to avoid a short circuit between both poles.

[0007] In one embodiment of the present technology, at least one processor of the above power supply device is configured to output a first permission signal and a second permission signal as at least one permission signal. The first AND gate element is configured to receive a first drive signal and the first permission signal and output their AND signal to the first relay and the third relay. The second AND gate element may be configured to receive a second drive signal and the second permission signal and output their AND signal to the second relay. That is, two permission signals may be respectively used for the two drive signals.

[0008] In one embodiment of the present technology, at least one processor of the above power supply device is configured to output only one of the first permission signal and the second permission signal as at least one permission signal. A NOT gate element that receives the first permission signal or the second permission signal and outputs its inverted signal may be provided between the processor and the first AND gate element or between the processor and the second AND gate element. That is, a single permission signal and its inverted signal may be used for the two drive signals. According to such a configuration, unintentional driving of each relay can be more reliably prevented.

[0009] In one embodiment of the present technology, at least one processor of the above power supply device may include a first processor that outputs a first drive signal or a second drive signal and a second processor that outputs at least one permission signal. According to such a configuration, even when one of the processors malfunctions, unintentional driving of each relay can be reliably prevented.

[0010] In one embodiment of the present technology, when turning on the first relay, the third relay, or the second relay, at least one processor of the above power supply device may switch the first drive signal or the second drive signal after switching at least one permission signal. According to such a configuration, when the processor or other components malfunction, both the drive signal and the permission signal are not erroneously output, and unintentional driving of each relay can be reliably prevented.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Modes for Carrying Out the Invention

[0012] (First Embodiment) Referring to the drawings, the power supply device 10 of the first embodiment will be described. Although it is an example, the power supply device 10 of this embodiment can be adopted for an electric vehicle. Note that the electric vehicle is not limited to a battery electric vehicle (BEV), and can also be similarly adopted for other types of electric vehicles. Further, the configuration described in this embodiment is not limited to an electric vehicle, and can also be similarly adopted for other types of devices and facilities that use electric power as a power source.

[0013] As shown in FIG. 1, the power supply device 10 includes a first battery 12a, a second battery 12b, a power unit 14, a first relay 16a, a second relay 16b, a third relay 16c, and a control device 18. The first battery 12a and the second battery 12b are high-voltage batteries. Here, the high voltage means an operating voltage exceeding 60V DC. The first battery 12a and the second battery 12b incorporate a plurality of secondary battery cells, and may be, for example, lithium-ion batteries or all individual batteries.

[0014] The power supply device 10 is mounted on an electric vehicle and supplies power to the power unit 14 of the electric vehicle. Although not particularly limited, the power unit 14 includes an electric motor that drives wheels, an inverter that controls the power supplied to the electric motor, and the like.

[0015] The first relay 16a is configured to electrically connect and disconnect between the positive electrode of the first battery 12a and the positive electrode of the second battery 12b. The second relay 16b is configured to electrically connect and disconnect between the negative electrode of the first battery 12a and the positive electrode of the second battery 12b. The third relay 16c is configured to electrically connect and disconnect between the negative electrode of the first battery 12a and the negative electrode of the second battery 12b. Although an example, the first relay 16a, the second relay 16b, and the third relay 16c in the present embodiment are electromagnetic drive type contact relays. Although details will be described later, the first relay 16a and the third relay 16c are driven in response to a first AND signal (AND1) output from the control device 18, and the second relay 16b is driven in response to a second AND signal (AND2) output from the control device 18.

[0016] The control device 18 is a device that switches the connection mode between the first battery 12a and the second battery 12b between parallel connection and series connection by controlling the operations of the three relays 16a, 16b, and 16c. This switching of the connection mode is performed according to the usage situation of the electric vehicle on which the power supply device 10 is mounted. For example, when the electric vehicle is running, the first battery 12a and the second battery 12b are connected in series, and when the electric vehicle is charging (that is, when the power supply device 10 is charging), the first battery 12a and the second battery 12b are connected in parallel.

[0017] As shown in FIG. 2, the control device 18 includes a processor 20, a first AND gate element 22, and a second AND gate element 24. The processor 20 is configured to output a first drive signal (DS1), a second drive signal (DS2), a first permission signal (AS1), and a second permission signal (AS2). The first drive signal and the first permission signal are input to the first AND gate element 22, and the second drive signal and the second permission signal are input to the second AND gate element 24.

[0018] The first drive signal is a drive signal for the first relay 16a and the third relay 16c, and is a binary signal that alternatively indicates an on command (HIGH) and an off command (LOW). The second drive signal is a drive signal for the second relay 16b, and is a binary signal that alternatively indicates an on command (HIGH) and an off command (LOW). The first permission signal is a signal for permitting the first relay 16a and the third relay 16c to turn on, and is a binary signal that alternatively indicates a permission command (HIGH) and a prohibition command (LOW). The second permission signal is a signal for permitting the second relay 16b to turn on, and is a binary signal that alternatively indicates a permission command (HIGH) and a prohibition command (LOW).

[0019] The first AND gate element 22 receives the first drive signal and the first permission signal, and outputs a first AND signal that is the logical product thereof. As described above, the first AND signal is input to the first relay 16a and the third relay 16c to drive the first relay 16a and the third relay 16c. Thus, as shown in FIG. 3, the first relay 16a and the third relay 16c are turned on only when the first drive signal indicates an on command (HIGH) and the first permission signal indicates a permission command (HIGH). On the other hand, the turning off of the first relay 16a and the third relay 16c is also achieved by either the off command (LOW) of the first drive signal or the prohibition command (LOW) of the first permission signal.

[0020] The second AND gate element 24 receives the second drive signal and the second permission signal, and outputs a second AND signal which is the logical product thereof. As described above, the second AND signal is input to the second relay 16b to drive the second relay 16b. Accordingly, the second relay 16b is turned on only when the second drive signal indicates an on command (HIGH) and the second permission signal indicates permission (HIGH). On the other hand, the turning off of the second relay 16b is also achieved by either only the off command (LOW) of the second drive signal or the prohibition command (LOW) of the second permission signal. That is, as shown in FIG. 3, while the second permission signal indicates a prohibition command, even if the second drive signal unintentionally indicates an on command, the off state of the second relay 16b is maintained.

[0021] As described above, in the power supply device 10 of the present embodiment, each of the relays 16a, 16b, 16c is not driven (particularly, turned on) only by the first drive signal or the second drive signal, and is driven only by a combination with the first permission signal or the second permission signal, respectively. Thereby, unintentional driving of each of the relays 16a, 16b, 16c is prevented, and in the first battery 12a and the second battery 12b, it is possible to avoid a short circuit between both electrodes. By preventing an excessive current from flowing through any of the relays 16a, 16b, 16c, damage to the relays 16a, 16b, 16c is avoided.

[0022] (Embodiment 2) With reference to FIG. 4, the power supply device of Embodiment 2 will be described. The power supply device of the present embodiment is obtained by changing the control device 18 in the power supply device 10 of Embodiment 1 described above to a control device 118 shown in FIG. 4. Since the other points are common to both embodiments, redundant descriptions will be omitted.

[0023] As shown in FIG. 4, the control device 118 in the second embodiment includes a processor 20, a first AND gate element 22, a second AND gate element 24, and a NOT gate element 30. The NOT gate element 30 is provided between the processor 20 and the second AND gate element 24. The NOT gate element 30 receives the first permission signal (AS1) output from the processor 20 and outputs the inverted signal thereof to the second AND gate element 24.

[0024] Therefore, in the control device 118 in the second embodiment, the second AND gate element 24 receives the second drive signal (DS2) and the inverted signal of the first permission signal (AS1), and outputs the second AND signal (AND2), which is the logical product thereof, to the second relay 16b. With such a configuration, as shown in FIG. 5, the second relay 16b is turned on only when the second drive signal indicates an on command (HIGH) and the first permission signal indicates a prohibition command (LOW). That is, the turning on of the second relay 16b is permitted only when the turning on of the first relay 16a and the third relay 16c is prohibited. Conversely, when the first permission signal indicates a permission command (HIGH), the turning on of the second relay 16b is prohibited and the turning on of the first relay 16a and the third relay 16c is permitted.

[0025] Thus, in the control device 118 in the second embodiment, by using a single first permission signal and its inverted signal for two drive signals, it is possible to reliably prevent the unintended driving (turning on) of each of the relays 16a, 16b, and 16c. As a modification, the NOT gate element 30 may be provided between the processor 20 and the first AND gate element 22. In this case, the processor 20 may be configured to output the second permission signal to the second AND gate element 24 and the NOT gate element 30, and the NOT gate element 30 may be configured to output the inverted signal of the second permission signal to the first AND gate element 22.

[0026] Although not particularly limited, as shown in FIG. 5, when turning on the first relay 16a and the third relay 16c, the processor 20 in the second embodiment is configured to switch the first drive signal after switching the first permission signal. According to such a configuration, when the processor 20 or other components malfunction, both the first drive signal and the first permission signal will not be erroneously output, and the unintended driving of the first relay 16a and the third relay 16c can be reliably prevented.

[0027] (Embodiment 3) Referring to FIG. 6, the power supply device of Embodiment 3 will be described. The power supply device of this embodiment is obtained by changing the control device 18 in the power supply device 10 of the above-described Embodiment 1 to the control device 218 shown in FIG. 6. Since the other points are common to both embodiments, duplicate explanations will be omitted.

[0028] As shown in FIG. 6, the control device 218 in Embodiment 3 includes a first processor 20a, a second processor 20b, a first AND gate element 22, a second AND gate element 24, and a NOT gate element 30. The first processor 20a outputs a first drive signal (DS1) and a second drive signal (DS2), and the second processor 20b outputs a first permission signal (AS1). The NOT gate element 30 is provided between the second processor 20b and the second AND gate element 24. The NOT gate element 30 receives the first permission signal output from the second processor 20b and outputs its inverted signal to the second AND gate element 24.

[0029] In the control device 218 in Embodiment 3, a second processor 20b that outputs a first permission signal is provided independently of the first processor 20a that outputs two drive signals. According to such a configuration, even when one of the two processors 20a and 20b malfunctions, the unintended driving of each relay 16a, 16b, 16c can be reliably prevented.

[0030] The technical elements described in this specification or the drawings exhibit technical utility either individually or in various combinations, and are not limited to the combinations recited in the claims at the time of filing. Further, the technologies exemplified in this specification or the drawings are capable of achieving a plurality of objectives simultaneously, and achieving one of those objectives by itself has technical utility.

Description of Reference Numerals

[0031] 10: Power supply device, 12a: First battery, 12b: Second battery, 14: Power unit, 16a: First relay, 16b: Second relay, 16c: Third relay, 18, 118, 218: Control device, 20: Processor, 22: First AND gate element, 24: Second AND gate element, 30: NOT gate element

Claims

1. A power supply device, a first battery, a second battery, a first relay for electrically connecting and disconnecting between the positive electrode of the first battery and the positive electrode of the second battery, a second relay for electrically connecting and disconnecting between the negative electrode of the first battery and the positive electrode of the second battery, a third relay for electrically connecting and disconnecting between the negative electrode of the first battery and the negative electrode of the second battery, a control device for controlling the operations of the first relay, the second relay, and the third relay, comprising: the control device includes at least one processor, a first AND gate element, and a second AND gate element, the at least one processor is configured to output a first drive signal for the first relay and the third relay, a second drive signal for the second relay, and at least one permission signal, the at least one permission signal includes at least one of a first permission signal for permitting the first relay and the third relay to be turned on and a second permission signal for permitting the second relay to be turned on, the first AND gate element is further configured to receive, in addition to the first drive signal, one of the first permission signal or the inverted signal of the second permission signal, and output their AND signal to the first relay and the third relay, the second AND gate element is further configured to receive, in addition to the second drive signal, the inverted signal of the first permission signal or one of the second permission signals, and output their AND signal to the second relay, a power supply device.

2. the at least one processor is configured to output the first permission signal and the second permission signal respectively as the at least one permission signal, the first AND gate element is configured to receive the first drive signal and the first permission signal, and output their AND signal to the first relay and the third relay, the second AND gate element is configured to receive the second drive signal and the second permission signal, and output their AND signal to the second relay, the power supply device according to Claim 1.

3. the at least one processor is configured to output only one of the first permission signal and the second permission signal as the at least one permission signal, Between the processor and the first AND gate element, or between the processor and the second AND gate element, a NOT gate element is provided that receives the first permission signal or the second permission signal and outputs its inverted signal. The power supply device according to claim 1.

4. The at least one processor includes a first processor that outputs the first drive signal or the second drive signal, and a second processor that outputs the at least one permission signal. The power supply device according to claim 1.

5. When the at least one processor turns on the first relay and the third relay or the second relay, after switching the at least one permission signal, the at least one processor switches the first drive signal or the second drive signal. The power supply device according to claim 1.

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