Battery discharge device

Abstract

To use an entire storage capacity by solving a problem of avoiding heat generation due to charge transfer between batteries when secondary batteries are connected in parallel and used as a power source in order to extend usable time of an electronic apparatus, since characteristics such as difference in a charged state and internal resistance are different for each individual, and contribute to Sustainable Development Goal 9 "Build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation," and Goal 11 "Make cities and human settlements inclusive, safe, resilient and sustainable."SOLUTION: A discharge device connected to a plurality of batteries includes a plurality of control switches and a plurality of low voltage detection circuits. Each control switch includes a first control input terminal and a second control input terminal. An output terminal of a low voltage detection circuit is connected to the first control input terminal. An output of a different low voltage detection circuit from the above is connected to the second control input terminal.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an apparatus for discharging multiple batteries. [Background technology]

[0002] As a power source for electronic devices, secondary batteries such as rechargeable nickel-metal hydride batteries and lithium-ion batteries may be used, or primary batteries such as manganese dry batteries may be used. When the battery capacity of a manganese dry battery is low, the batteries may be connected in parallel to extend the usable time of the electronic device, but it is considered difficult to connect secondary batteries in parallel. The reason for this is that secondary batteries have different charging states and characteristics such as internal resistance, so when they are connected in parallel to be used as a power source, there are problems such as heat generation due to current flow between the batteries and a limited time for stable discharge. For this reason, in devices that use secondary batteries as a power source, even if the device is equipped with multiple batteries, a method of connecting the batteries to the load by switching them in sequence, or a technology of controlling the order of the batteries connected in parallel has been proposed, and these are described in, for example, Patent Documents 1 and 2 below. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 3312428 [Patent Document 2] Special Publication No. 2022-517404 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the disclosures of Patent Documents 1 and 2 have problems such as the large number of parts constituting the control circuit, which makes the battery system large, and the control circuit uses power from the battery and consumes the battery's storage capacity, which shortens the battery usage time, etc. The present invention has been made in consideration of these circumstances, and aims to provide a discharge device that performs battery switching more easily. [Means for solving the problem]

[0005] In order to solve the above problems, a discharge device for connecting to a plurality of parallel-connected batteries according to one embodiment of the present invention includes a plurality of control switches and a plurality of low-voltage detection circuits. The control switches include a first control input terminal and a second control input terminal, the first control input terminal is connected to an output terminal of a low-voltage detection circuit, and the second control input terminal is connected to an output terminal of another low-voltage detection circuit. Effect of the Invention

[0006] According to the present invention, it is possible to sequentially discharge a plurality of batteries connected in parallel, making it possible to use the capacity of the plurality of batteries without wasting it, and thus realizing a more suitable discharge device. [Brief description of the drawings]

[0007] [Figure 1] 1 is a configuration diagram of a discharge device according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram showing a specific configuration of a discharge device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, the embodiments of the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the description of the embodiments, and various changes and modifications can be made by those skilled in the art within the scope of the technical ideas disclosed in this specification. In addition, in all the drawings for explaining the present invention, the same reference numerals are given to the parts having the same functions, and the repeated description may be omitted.

[0009] Fig. 1 is a diagram showing the overall configuration of a discharge device according to an embodiment of the present invention. The discharge device, which is connected to a plurality of batteries (primary batteries or secondary batteries) (102, 103, 104) connected in parallel, is composed of a power source 101, a discharge switch (105, 106, 107), a charge switch (108, 109, 110), a low-voltage detection circuit (111, 112, 113), a load 114, and a terminal 115. The plurality of batteries, for example, primary batteries or secondary batteries, may be composed of different types of batteries, may be composed of different types of secondary batteries, or may be composed of all-solid-state batteries. The plurality of batteries (102, 103, 104) are connected in parallel. On the other hand, if the power source generated from the commercial power source is used as the battery 102, the power source generated from the auxiliary power source is used as the battery 103, and the power source such as a battery is used as the battery 104, and these are connected to a discharge device, the device can operate from the auxiliary power source when the commercial power source is lost, and can also operate from the power source from the battery when the auxiliary power source is lost. This embodiment will be described using an all-solid-state battery (secondary battery).

[0010] The discharge switch may be referred to as a control switch. The discharge switches (105, 106, 107) may be referred to as a first discharge switch 105, a second discharge switch 106, and a third discharge switch 107, respectively. The charge switches (108, 109, 110) may be referred to as a first charge switch 108, a second charge switch 109, and a third charge switch 110, respectively. The low voltage detection circuits (111, 112, 113) may be referred to as a first low voltage detection circuit 111, a second low voltage detection circuit 112, and a third low voltage detection circuit 113, respectively. In addition, the low voltage detection circuit includes an output terminal for turning on the discharge switch (control switch) and an output terminal for turning off the discharge switch (control switch).

[0011] As shown in FIG. 1, batteries (102, 103, 104) are connected in parallel. The high potential side of the battery 102 is connected to a discharge switch 105. The discharge switch 105 is connected to a terminal 115 and a low voltage detection circuit 111. The low potential side of the battery 102 is connected to a load 114. Specifically, a first control input terminal of the discharge switch 105 is connected to the terminal 115, and a second control input terminal of the discharge switch 105 is connected to an output terminal for turning off the discharge switch of the first low voltage detection circuit 111. The high potential side of the battery 103 is connected to a discharge switch 106. The discharge switch 106 is connected to the low voltage detection circuit 111 and the low voltage detection circuit 112. The low potential side of the battery 103 is connected to the load 114. A first control input terminal of the discharge switch 106 is connected to an output terminal of the first low-voltage detection circuit 111, specifically, an output terminal for turning on the discharge switch of the first low-voltage detection circuit 111. A second control input terminal of the discharge switch 106 is connected to an output terminal of the second low-voltage detection circuit 112, specifically, an output terminal for turning off the discharge switch of the second low-voltage detection circuit 112.

[0012] In addition, the high potential side of the battery 104 is connected to a discharge switch 107. The discharge switch 107 is connected to a low voltage detection circuit 112 and a low voltage detection circuit 113. The low potential side of the battery 104 is connected to a load 114. A first control input terminal of the discharge switch 107 is connected to an output terminal of the second low voltage detection circuit 112, specifically, to an output terminal for turning on the discharge switch of the second low voltage detection circuit 112. A second control input terminal of the discharge switch 107 is connected to an output terminal of the third low voltage detection circuit 113, specifically, to an output terminal for turning off the discharge switch of the third low voltage detection circuit 113.

[0013] Alternatively, the first control input terminal of each discharge switch (control switch) is connected to an output terminal for turning on a discharge switch (control switch) of a different low-voltage detection circuit, and the second control input terminal is connected to an output terminal for turning off a discharge switch (control switch) of a low-voltage detection circuit different from the above. The first control input terminal of the discharge switch (control switch) connected to one of the batteries connected in parallel is connected to a terminal, and the second control input terminal is connected to the output terminal of the low-voltage detection circuit. Also, the first control input terminal of the discharge switch (control switch) connected to one of the batteries connected in parallel is connected to the output terminal of the low-voltage detection circuit, and the second control input terminal is connected to a load.

[0014] When the charging switches (108, 109, 110) are turned on, the voltage from the power source 101 is supplied to the batteries (102, 103, 104) and charging is started. When the charging switches (108, 109, 110) are turned off, charging is terminated. The discharge switch 105 is connected between the battery 102 and the load 114, and the on and off states of the discharge switch 105 are controlled by control information of the terminal 115 and information of the low voltage detection circuit 111. For example, by controlling the discharge switch 105 to be turned on when the terminal 115 becomes zero potential (negative potential of the battery 102) and to be turned off when the low voltage detection circuit 111 detects a voltage below a predetermined threshold, power can be supplied to the load 114 during the period when the potential of the battery 102 is above the predetermined threshold. The discharge switch 106 is connected between the battery 103 and the load 114, and is turned on by information from the low-voltage detection circuit 111, and is controlled to be turned off by information from the low-voltage detection circuit 112. Therefore, when the low-voltage detection circuit 111 detects a voltage below a predetermined threshold, the discharge switch 105 turns off and the discharge switch 106 turns on at the same time, allowing power to be supplied from the battery 103 to the load 114. Power can be supplied to the load 114 during the period until the low-voltage detection circuit 112 detects a voltage below the predetermined threshold and turns the discharge switch 106 off.

[0015] Similarly, the discharge switch 107 is connected between the battery 104 and the load 114, and is turned on by information from the low-voltage detection circuit 112, and is controlled to be turned off by information from the low-voltage detection circuit 113. Therefore, when the low-voltage detection circuit 112 detects a voltage below a predetermined threshold, the discharge switch 106 turns off and the discharge switch 107 turns on at the same time, allowing power to be supplied from the battery 104 to the load 114. Power can be supplied to the load 114 until the low-voltage detection circuit 113 detects a voltage below a predetermined threshold and turns the discharge switch 107 off. As described above, the load 114 can operate so as to supply power to the batteries (102, 103, 104) in sequence. These operations will be described in more detail with reference to FIG. 2.

[0016] Fig. 2 is a diagram showing a specific circuit configuration of a portion of an embodiment of the discharge device for realizing the operation of Fig. 1. The discharge switch 105 is composed of P-channel MOS transistors (121, 122) and resistors (141, 142). When a voltage close to 0V, which is close to the negative electrode potential of the battery 102, is supplied from the terminal 115, the gate potential of the MOS transistor 121 drops via the resistor 141, the source terminal and drain terminal of the MOS transistor 121 become conductive, and the voltage (V102) of the battery 102 is supplied to the series element connecting the resistors 143 and 144. A voltage obtained by dividing the voltage V102 by the resistors (143, 144) is supplied to the gate terminal of the N-channel MOS transistor 123. The values ​​of the resistors (143, 144) are set to be the threshold voltage at which the MOS transistor 123 turns on, and the gate potential of the MOS transistor 122 drops via the body diode and resistor 142, causing electrical continuity between the source terminal and the drain terminal of the MOS transistor 122, and power is supplied to the load 114.

[0017] When the voltage V102 drops, the potential divided by the resistors (143, 144) also drops, and when the threshold value of the MOS transistor 123 drops, it turns off and the power supply from the battery 102 to the load 114 stops.

[0018] At the same time, the gate potential of the N-channel MOS transistor 124 drops and it is turned off. The potential that was lowered by the resistor 145 rises to the voltage (V103) of the battery 103, the N-channel MOS transistor 125 is turned on, the source terminal and the drain terminal of the P-channel MOS transistor 126 are conductive, and the voltage V103 is supplied to the series element of the resistors 148 and 149. A voltage obtained by dividing the voltage V103 by the resistors (148, 149) is supplied to the gate terminal of the N-channel MOS transistor 128. The values ​​of the resistors (148, 149) are set to be the threshold voltage at which the MOS transistor 128 is turned on, the gate potential of the MOS transistor 127 drops via the body diode and the resistor 147, the source terminal and the drain terminal of the MOS transistor 127 are conductive, and power is supplied from the battery 103 to the load 114.

[0019] When the voltage V103 drops, the potential divided by the resistors (148, 149) also drops, and when the threshold value of the MOS transistor 128 drops, it turns off and the power supply from the battery 103 to the load 114 stops.

[0020] At the same time, the gate potential of the N-channel MOS transistor 129 drops and the transistor is turned off. The potential that had been lowered by the resistor 152 rises to the voltage (V104) of the battery 104, the N-channel MOS transistor 130 is turned on, the source terminal and drain terminal of the P-channel MOS transistor 131 are conductive, and the voltage V104 is supplied to the series element of the resistors 153 and 154. A voltage obtained by dividing the voltage V104 by the resistors (153, 154) is supplied to the gate terminal of the N-channel MOS transistor 133. The values ​​of the resistors (153, 154) are set to be the threshold voltage at which the MOS transistor 133 is turned on, the gate potential of the MOS transistor 132 drops via the body diode and the resistor 151, the source terminal and drain terminal of the MOS transistor 132 are conductive, and power is supplied from the battery 104 to the load 114.

[0021] When the voltage V104 drops, the potential divided by the resistors (153, 154) also drops, and when the threshold value of the MOS transistor 133 drops, it turns off and the power supply from the battery 104 to the load 114 stops.

[0022] The discharge switch or control switch of this embodiment is configured by connecting two P-channel MOS transistors in series and connecting a low-voltage detection circuit to the connection point of the series connection. The discharge switch or control switch is also configured by connecting two P-channel MOS transistors back-to-back and connecting a low-voltage detection circuit to the connection point of the back-to-back connection.

[0023] As described above, the load 114 can be operated so as to be able to supply power to the batteries (102, 103, 104) in order. As a result, even when the stored power amounts of the respective batteries (102, 103, 104) are different, the stored power can be used up. Further, for example, by setting the voltage division value by the resistors (143, 144) to a voltage value at which the battery 102 does not over-discharge, it can be protected and the life of the battery can be maintained. Furthermore, in the case of the charging process, since the remaining capacity of the battery can always be set to a constant value, there is an effect of preventing overcharging, and a more suitable discharging device can be realized.

[0024] In this embodiment, three batteries are used for explanation. However, when there are n batteries, there are n discharge switches or control switches, and n low-voltage detection circuits. When 2 < i < n, the connection order of the batteries is the i-th, and the first control input terminal of the i-th control switch is connected to the output terminal of the control switch of the (i - 1)-th low-voltage detection circuit, and the second control input terminal of the i-th control switch is connected to the output terminal of the i-th low-voltage detection circuit. Specifically, the first control input terminal of the i-th control switch is connected to the output terminal for turning on the control switch of the (i - 1)-th low-voltage detection circuit, and the second control input terminal of the i-th control switch is connected to the output terminal for turning off the control switch of the i-th low-voltage detection circuit. Here, n is a natural number, and i is a natural number. Sequential discharge of a plurality of batteries charged in parallel becomes possible, and the capacities of the plurality of batteries can be used without waste, and a more suitable discharging device can be realized.

[0025] According to the above embodiment, after the first battery starts discharging, when the voltage drop of the first battery is detected and the voltage becomes lower than the target voltage, the second battery is connected and at the same time, the connection of the first battery is released. Further, after the second battery starts discharging, when the voltage drop of the second battery is detected and the voltage becomes lower than the target voltage, the third battery is connected and at the same time, the connection of the second battery is released, so that the stored power capacities of the individual batteries can be consumed in order.

[0026] In addition, the technology according to the present embodiment can provide a charging and discharging system with excellent energy efficiency, which contributes to the achievement of "9. Build resilient infrastructure, promote inclusive and sustainable industrialization, promote innovation and build resilient cities and communities" and "11. Make cities and communities sustainable and livable" of the Sustainable Development Goals (SDGs) proposed by the United Nations.

[0027] Although various embodiments have been described above in detail, the present invention is not limited to the above-described embodiments and includes various modified examples. For example, the above-described embodiments are detailed descriptions of the entire system in order to clearly explain the present invention, and are not necessarily limited to those having all of the configurations described. In addition, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. In addition, it is possible to add, delete, or replace a part of the configuration of each embodiment with another configuration. [Explanation of symbols]

[0028] 101...power source, 102...battery, 103...battery, 104...battery, 105...discharge switch, 106...discharge switch, 107...discharge switch, 111...low voltage detection circuit, 112...low voltage detection circuit, 113...low voltage detection circuit

Claims

1. 1. A discharge device for connection to a plurality of parallel connected batteries, comprising: A plurality of control switches; A plurality of low voltage detection circuits; the control switch has a first control input terminal and a second control input terminal; the first control input terminal is connected to an output terminal of the low voltage detection circuit; The second control input terminal is connected to an output terminal of a low voltage detection circuit different from the above. Discharge device.

2. The discharge device according to claim 1, the low voltage detection circuit includes an output terminal for turning on the control switch and an output terminal for turning off the control switch. Discharge device.

3. The discharge device according to claim 1, an output terminal for turning on a control switch of a different low-voltage detection circuit is connected to a first control input terminal of each of the control switches, and an output terminal for turning off a control switch of a low-voltage detection circuit different from the control switch is connected to a second control input terminal of each of the control switches. Discharge device.

4. The discharge device according to claim 1, A control switch connected to one of the parallel-connected batteries has a first control input terminal connected to the terminal and a second control input terminal connected to the output terminal of the low-voltage detection circuit. Discharge device.

5. The discharge device according to claim 1, A control switch connected to one of the parallel-connected batteries has a first control input terminal connected to the output terminal of the low-voltage detection circuit and a second control input terminal connected to a load. Discharge device.

6. The discharge device according to claim 1, When the number of the batteries is n, the number of the control switches is n, and the number of the low voltage detection circuits is n. For 2<i<n, The battery is connected in the i-th order, a first control input terminal of the i-th control switch is connected to an output terminal of the (i-1)-th low voltage detection circuit; a second control input terminal of the i-th control switch is connected to an output terminal of the i-th low voltage detection circuit; Discharge device.

7. The discharge device according to claim 6, the control switch is configured by connecting two P-channel MOS transistors in series, and connecting the low voltage detection circuit to a connection point of the series connection; Discharge device.

8. The discharge device according to claim 7, The control switch is configured by configuring two P-channel MOS transistors in a back-to-back arrangement and connecting a low-voltage detection circuit to a connection point of the back-to-back arrangement. Discharge device.

9. A discharge device according to any one of claims 1 to 8, The plurality of batteries are composed of different types of batteries. Discharge device.

10. A discharge device according to any one of claims 1 to 8, The plurality of batteries are composed of different types of secondary batteries. Discharge device.

11. A discharge device according to any one of claims 1 to 8, The plurality of batteries are composed of all-solid-state batteries. Discharge device.

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