Power supply with battery cells

Abstract

A fuse element of an SCP is reliably fused to cut off current by a simple circuit structure. A power supply with a battery unit controls the on-off of a switch (6) by a control circuit (7), the switch (6) connecting an SCP3, which is connected in series with the battery unit (1) and cuts off charge-discharge current in an abnormal state, to the battery unit (1). The battery unit (1) has a plurality of single cells (2) connected in series, the SCP3 has a fuse element (4) connected in series to an output side of the battery unit (1) and a heater (5) that fuses the fuse element (4), the switch (6) has a plurality of switch elements (10) that connect one terminal to the heater (5) and the other terminal to different voltage terminals (11) of the battery unit (1), and the control circuit (7) selects a switch element (10) that is switched to an on state by a detection voltage of a voltage detection circuit (8) by a selection circuit (9), the switch element (10) in the on state connecting the battery unit (1) to the heater (5) to fuse the fuse element (4).

Description

Technical Field

[0001] This invention relates to a power supply that is connected in series with a battery cell to an SCP (Self-Control Protector). Background Technology

[0002] A power supply equipped with a battery cell is connected to an SCP on the output side, which cuts off the current in case of an anomaly. The SCP has a fuse element connected in series with the battery cell and a heater that melts the fuse element by Joule heating. The heater and fuse element are configured in a near-thermal coupling state and are connected to the battery cell via a switch, heating by Joule heating. The switch is switched to the ON state in case of an anomaly on the battery or load side. The ON switch supplies power from the battery cell to the heater, causing the heater to heat up. The heater is heated by power supplied from the battery cell, but if the power supplied from the battery cell to the heater is too small, the heat generated by the Joule heating of the heater is insufficient to heat the fuse element to its melting temperature and melt it. Conversely, if the power supplied from the battery cell is too large, it will burn out and fail to heat the fuse element to melt it. In order for the power supply to reliably melt the fuse element and cut off the current output in case of an anomaly by using a set range of power supplied to the heater from the battery cell, the power supply is required to be set within a set range.

[0003] A battery cell, consisting of multiple individual cells connected in series, experiences voltage fluctuations as it is charged and discharged. Especially due to its large charge / discharge capacity, lithium-ion secondary batteries, used in various applications, exhibit significant voltage variations relative to their remaining capacity. The voltage changes drastically between a fully charged cell with nearly 100% remaining capacity and a cell discharged to near 0% remaining capacity. This leads to the drawback of significant power supply fluctuations when the battery cell is connected to a heater.

[0004] For example, the commercially available SCP (SFK-5045x) has a heater with a fuse element operating at a voltage of 43.7–62V. This SCP is connected to a battery cell consisting of 14 individual cells connected in series. When voltage is supplied from the battery cells to the heater, the voltage of each individual cell within the heater's operating voltage range is 3.15–4.35V. Therefore, if the voltage of any individual cell in the battery cell drops below 3.15V, the SCP cannot be fused; similarly, if the voltage of any individual cell drops below 3V, the SCP cannot be fused, thus preventing the battery pack from charging and discharging.

[0005] To prevent the above drawbacks, a power supply was developed that supplies power from the battery cell to the heater via a constant current circuit. (Patent Document 1)

[0006] Prior art literature

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2019-208319 Summary of the Invention

[0009] -The problem the invention aims to solve-

[0010] The power supply that supplies electricity to the heater of the SCP via the battery cell through a constant current circuit is independent of the voltage fluctuations of the battery cell, enabling the heater to heat up with a constant current. Therefore, even if the battery cell voltage changes, the heat output of the heater remains constant. This is because the Joule heat required to heat the heater is determined by the product of the square of the current and the resistance of the heater. Thus, the power supply from the battery cell to the heater via the constant current circuit can, in an optimal state, heat the heater to the point of blowing the fuse. However, the constant current circuit causes the voltage of the battery cell to decrease due to the voltage drop across the internal resistance of the semiconductor element, maintaining the output voltage at a constant value. Therefore, the internal resistance of the semiconductor element, such as a transistor or FET, which causes the voltage to drop, heats up due to Joule heat. The heating of the semiconductor element increases proportionally to the product of the square of the current and the internal resistance. However, in a typical SCP, the heater current required to blow the fuse is around several amperes, which in turn reduces the battery cell voltage due to the internal resistance. Therefore, considering the heat generated during the short period of operation until the fuse blows, the constant current circuit becomes larger, leading to a more complex circuit configuration.

[0011] The purpose of this invention is to eliminate the above-mentioned disadvantages. The important objective of this invention is to provide a power supply with a battery cell that can reliably melt the fuse element of the SCP to cut off the current with a simple circuit structure.

[0012] -Methods for solving problems-

[0013] One aspect of the present invention relates to a power supply comprising a battery cell: a battery cell; an SCP (Self-Control Protector) connected in series with the battery cell to cut off the charging and discharging current in abnormal conditions; a switch connecting the SCP to the battery cell; and a control circuit for controlling the switching on and off. The battery cell comprises multiple individual cells connected in series. The SCP comprises: a fuse element connected in series with the output side of the battery cell; and a heater connected to the battery cell, which heats by Joule heating to melt the fuse element. The switch comprises: multiple switching elements, one terminal of which is connected to the heater, and the other terminal of which is connected to multiple terminals with different voltages different from the voltage of the battery cell. The control circuit comprises: a voltage detection circuit for detecting the voltage of the battery cell or individual cells; and a selection circuit for selecting a switching element to be switched to the on state based on the voltage detected by the voltage detection circuit. In abnormal conditions, the selection circuit selects a switching element to be switched to the on state, and the on-state switching element connects the battery cell to the heater, thus melting the fuse element.

[0014] -Invention Effects-

[0015] A power source equipped with the above battery units can reliably melt the SCP's fuse element to cut off the current with a simple circuit structure. Attached Figure Description

[0016] Figure 1 This is a schematic structural diagram of a power supply with a battery cell according to one embodiment of the present invention. Detailed Implementation

[0017] The power supply of the battery cell according to an embodiment of the present invention includes: a battery cell; an SCP (Self-Control Protector) connected in series with the battery cell to cut off the charging and discharging current in an abnormal state; a switch connecting the SCP and the battery cell; and a control circuit that controls the switching on and off. The battery cell includes multiple individual cells connected in series. The SCP includes: a fuse element connected in series with the output side of the battery cell; and a heater connected to the battery cell, which melts the fuse element by using Joule heating. The switch includes multiple switching elements, each of which connects one terminal to the heater and another terminal to multiple terminals with different voltages from the battery cell. The control circuit includes: a voltage detection circuit that detects the voltage of the battery cell or individual cells; and a selection circuit that selects the switching element to switch to the on state using the voltage detected by the voltage detection circuit. In an abnormal state, the selection circuit selects the switching element to switch to the on state, and the on state switching element connects the battery cell to the heater, thus melting the fuse element.

[0018] The voltage changes of the power supply and battery cells / single cells are correspondingly selected by choosing different voltage terminals to connect the heater and the battery cells. Therefore, even when the voltage of the battery cells / single cells fluctuates, the voltage supplied from the battery cells to the heater can be set within a certain range, allowing the battery cells to heat the heater and reliably blow the fuse. Since the battery cell connects multiple single cells in series, the voltage at the connection point of the series-connected single cells becomes an integer multiple of the single cell voltage from the negative side to the positive side. The single cell voltage varies with its remaining capacity and is therefore not fixed, but the voltage at different voltage terminals gradually increases from the negative side to the positive side of the connection point. For example, in a battery cell with 10 single cells connected in series, the total voltage is 10 times the single cell voltage, and the voltage at the different voltage terminals at the middle connection point is 5 times. Therefore, when the single cell voltage drops to half of its maximum voltage, the total voltage of the battery cell is supplied to the heater via a switching element. When the single cell voltage rises to its maximum voltage, the same voltage can be supplied to the heater by energizing the switching element connected to the different voltage terminals at the middle connection point.

[0019] The above power supply, for example, uses an SCP (SFK3045x) with the operating voltage of the heater that blows the fuse element set to 22.3 to 31.5V. The first to third switching elements are selected so that the voltage of the single cell is supplied to the heater from the single cell in 7-cell, 9-cell, or 12-cell configurations to make it in the on state. The operating voltage of the heater is set within the above range so that the fuse element can be blown.

[0020] The first switching element supplies voltage to the heater from seven individual cells within a single cell voltage range of 3.2 to 4.35 V. Under these single cell voltages, the supply voltage to the heater is 22.4 to 30.45 V.

[0021] The second switching element supplies voltage to the heater from nine individual cells within a single cell voltage range of 2.5 to 3.5V. Under these single cell voltages, the supply voltage to the heater is 22.5 to 31.5V.

[0022] The third switching element supplies voltage to the heater from the 12 cells in series, with the single-cell voltage set to a range of 1.9 to 2.6V. Under these single-cell voltages, the supply voltage to the heater is 22.8 to 31.2V.

[0023] The above power supply supplies voltage from the battery cell to the heater of the SCP via the first to third switching elements. However, when the power supply device with 4 sets of switching elements supplies voltage from 14 individual cells to the heater when the voltage of a single cell drops to 1.6 to 2.2V, the supply voltage of the heater is set to 22.4 to 30.8V, and the fourth switching element can be set to the specified operating voltage.

[0024] In another embodiment of the present invention, the power supply having a battery unit has a detection unit for detecting abnormal states of the control circuit. When the detection unit detects an abnormal state, it sets the switching element to the on state and melts the fuse element.

[0025] In another embodiment of the present invention, in a power supply having battery cells, the detection unit includes an AFE (analog front end) for detecting the voltage of each individual cell and an MPU (microprocessor unit) for detecting the total voltage of the battery cells. The voltage of each individual cell detected by the AFE and the total voltage of the battery cells detected by the MPU are compared with a threshold to determine an anomaly.

[0026] In another embodiment of the present invention, the power supply detection unit of the battery cell includes an overcharge detection unit for detecting overcharge of the battery cell, and the overcharge detection unit detects overcharge of the battery cell and blows the fuse element of the SCP.

[0027] The above power supply directly controls the switching element to blow the fuse element of the SCP through the overcharge detection unit. Therefore, it has the advantage of reliably preventing the charging and discharging of the battery cell and preventing overcharging even if the voltage detection circuit of the control circuit or the like malfunctions.

[0028] In other embodiments of the present invention, the detection unit of the power supply having a battery cell detects the temperature of the battery cell or a single cell and compares the detected temperature with a threshold to determine an abnormal state.

[0029] In other embodiments of the present invention, the power supply having a battery cell is connected in series with each switching element, and diodes are connected in the energizing direction of the switching elements.

[0030] The power supply described above has the advantage of reliably blowing the SCP fuse by controlling multiple switching elements to the ON state simultaneously. This is because the switching elements simultaneously switched to the ON state are supplied with voltage only from the switching element supplied with the maximum voltage. The power supply also achieves the advantage of reliably blowing the SCP fuse by controlling multiple switching elements to the ON state within the boundary region of selecting the individual cell voltages of each switching element.

[0031] In other embodiments of the present invention, the power supply having a battery cell uses a FET as the switching element.

[0032] The present invention will now be described in detail with reference to the accompanying drawings. Furthermore, in the following description, terms indicating specific directions or positions (e.g., "up," "down," and other terms including these terms) are used as needed, but their use is for ease of understanding of the invention with reference to the drawings and does not limit the technical scope of the invention based on the meaning of these terms. Additionally, the same symbols appearing in multiple drawings represent the same or equivalent parts or components.

[0033] Furthermore, the embodiments shown below represent specific examples of the technical concept of the present invention, and the present invention is not limited to the following. Moreover, unless specifically stated otherwise, the dimensions, materials, shapes, and relative arrangements of the constituent components described below are not intended to limit the scope of the present invention, but are merely illustrative. Furthermore, the content described in one embodiment or example can be applied to other embodiments or examples. Additionally, for clarity, the size and positional relationships of the components shown in the drawings are sometimes exaggerated.

[0034] (Implementation Method 1)

[0035] Figure 1The power supply 100 includes: a battery unit 1; an SCP3 (self-control protector) connected in series with the output side of the battery unit 1 to cut off the charging and discharging current in abnormal conditions of the battery unit 1 and the load; a switch 6 that connects the SCP3 to the battery unit 1 and supplies power to the heater 5 of the SCP3 through the power of the battery unit 1 to blow the fuse element 4; and a control circuit 7 that controls the switching on and off of the switch 6 in abnormal conditions.

[0036] (Battery Unit 1)

[0037] The battery unit 1 comprises multiple individual cells 2 connected in series. The individual cells 2 are suitable for non-aqueous electrolyte secondary batteries such as lithium-ion secondary batteries with large charge / discharge capacity. However, this invention does not specify that each individual cell is a lithium-ion secondary battery; any currently used or future-developed secondary battery, such as nickel-metal hydride batteries or any individual battery, can be used.

[0038] Battery cell 1 increases the output voltage by connecting multiple individual cells 2 in series. In this battery cell 1, the voltage at the intermediate connection point of the multiple individual cells 2 connected in series gradually increases. For example, in battery cell 1 where individual cells 2, each with a rated voltage of 3.7V, are connected in series, the voltage at the connection point of the individual cells 2 gradually increases from the negative side to the positive side, becoming an integer multiple of the individual cell voltage. Therefore, the voltage at the intermediate connection point of the individual cells 2 connected in series gradually increases. Figure 1 Battery cell 1 uses intermediate connection points with different voltages as different voltage terminals 11, which are connected to heater 5 of SCP3 via switching element 10. Different voltage terminals 11 are provided to adjust the voltage supplied to heater 5 of SCP3. The voltage of battery cell 1 changes from a fully charged state to a fully discharged state. For example, since a lithium-ion secondary battery has a fully charged voltage of 4.2V and a fully discharged voltage of 2.8V, the total voltage of battery cell 1 with 10 individual cells 2 connected in series changes from 28V to 42V, and the total voltage of battery cell 1 with 14 individual cells 2 connected in series changes from 39.2V to 58.8V.

[0039] In order to supply a voltage within a set range to the heater 5 of the SCP3 from multiple individual cells 2 with varying voltages via a switching element 10, the battery unit 1 is provided with multiple different voltage terminals 11 connected in series with different numbers of individual cells 2. When the voltage of an individual cell 2 decreases, the switching element 10 is connected to the different voltage terminals 11 that supply power to the heater 5 of the SCP3 with more individual cells 2 connected in series; conversely, when the voltage of an individual cell 2 increases, the switching element 10 is connected to the different voltage terminals 11 that supply power to the heater 5 of the SCP3 with fewer individual cells 2 connected in series, thereby adjusting the voltage supplied to the heater 5 of the SCP3 to the set range.

[0040] Figure 1 The battery unit 1 is provided with first to third different voltage terminals 11a, 11b, and 11c. When the voltage of the single cell 2 changes, the battery unit 1 switches between the different voltage terminals 11 connected to the SCP3 to output a voltage within a set range to the SCP3. For example, the SCP3 of the surface-mount fuse "SFK3045x" from Deehide Corporation has a supply voltage range of 22.3 to 31.5V, but this SCP3 can be connected to the SCP3 via the switching element 10 from the first to third different voltage terminals 11a, 11b, and 11c, thus blowing the fuse element 4.

[0041] The first different voltage terminal 11a is connected to SCP3 when the single cell voltage varies from 3.2 to 4.35V, and the output voltage from the 7-cell single cell 2 becomes 22.4 to 30.45V.

[0042] The second different voltage terminal 11b is connected to SCP3 when the single cell voltage varies from 2.5 to 3.5V, and the output voltage from the nine single cells 2 becomes 22.5 to 31.5V.

[0043] The third different voltage terminal 11c is connected to SCP3 when the single cell voltage varies from 1.9 to 2.6V, and the output voltage from the 12-cell single cell 2 becomes 22.8 to 31.2V.

[0044] (Switch 6)

[0045] The switch 6 has multiple switching elements 10 connected to multiple different voltage terminals 11. Figure 1 The power supply 100 includes first to third switching elements 10a, 10b, and 10c connected to first to third different voltage terminals 11a, 11b, and 11c. The switch 6 connects each different voltage terminal 11 to the SCP3, and is therefore composed of the same number of switching elements 10 as the different voltage terminals 11. Figure 1 The power supply 100 has three sets of different voltage terminals 11 in the battery cell 1, so three sets of switching elements 10 are used. However, the power supply of the battery cell with two sets of different voltage terminals connects each different voltage terminal to the SCP through two sets of switching elements. The power supply with four or more sets of different voltage terminals connects each different voltage terminal to the SCP through four or more sets of switching elements.

[0046] The first to third switching elements 10a, 10b, and 10c are preferably FETs. Figure 1The power supply 100 uses an n-channel FET in each switching element 10, with the drain connected to SCP3 via diode 12, the source connected to battery cell 1, and the gate connected to control circuit 7. While the power supply 100 uses an n-channel FET for the switching element 10, other semiconductor switching elements capable of switching on and off, such as p-channel FETs and bipolar transistors, can also be used.

[0047] Figure 1 Switch 6 connects diode 12 in series with switching element 10. Diode 12 is connected in the energizing direction of switching element 10 when it is in the ON state. Diode 12 connected to switching element 10 is in the energizing direction of switching element 10. Figure 1 In an n-channel FET, current flows from the drain to the source, and the current flowing in the opposite direction is cut off. Therefore, when multiple FETs are switched on, power is supplied to the heater 5 of SCP3 only from the FETs connected to different voltage terminals 11 with the maximum voltage.

[0048] Figure 1 The power supply 100, for example, turns on the first switching element 10a when the single-cell voltage of battery cell 1 is in the range of 3.2 to 4.35V, turns on the second switching element 10b when the single-cell voltage is in the range of 2.5 to 3.5V, and turns on the third switching element 10c when the single-cell voltage is in the range of 1.9 to 2.5V. When the single-cell voltage of battery cell 1 is 3.3V, the first switching element 10a and the second switching element 10b are turned on, but the current of the second switching element 10b flows through the diode 12, while the current of the first switching element 10a is cut off by the diode 12. Within the range of 2.5V for the single-cell voltage of battery cell 1, the second switching element 10b and the third switching element 10c are switched on. However, in this state, the current flowing from battery cell 1 to SCP3, specifically the current of the third switching element 10c, becomes the forward current of diode 12, while the current of the second switching element 10b becomes the reverse current of diode 12. Therefore, the third switching element 10c supplies current from battery cell 1 to SCP3. As described above, the power supply 100, in which diodes 12 are connected in series with each switching element 10, has the following advantages: at the boundary voltage of the single-cell voltage selection switching element 10, switching multiple switching elements 10 to the on state reliably supplies current from battery cell 1 to SCP3, and can melt the fuse element 4 of SCP3. In particular, within the entire range of varying single-cell voltage, it is possible to reliably supply power from battery cell 1 to SCP3, and melt the fuse element 4 by heating it with heater 5.

[0049] (Control Circuit 7)

[0050] In an abnormal state, control circuit 7 switches switching element 10 from open to closed, energizing the heater 5 of SCP3 from battery cell 1 and blowing fuse element 4. Control circuit 7 includes: a voltage detection circuit 8 that detects the voltage of battery cell 1 or single cell 2; and a selection circuit 9 that selects the switching element 10 to be switched to the closed state based on the voltage detected by voltage detection circuit 8. In an abnormal state, selection circuit 9 selects the switching element 10 to be switched to the closed state, connecting battery cell 1 to heater 5 via the closed switching element 10 and blowing fuse element 4. Control circuit 7 selects switching element 10 based on the voltage of single cell 2, supplying a voltage within a given set range from battery cell 1 to SCP3.

[0051] This invention does not define abnormal states, but abnormal states include, for example, states that cut off the current to battery cell 1 to achieve safety, or states that protect battery cell 1. In such states, the fuse element 4 of SCP3 connected to the output side of battery cell 1 is melted to cut off the current. Specifically, the control circuit 7 determines abnormal states such as: the total voltage of battery cell 1 or the voltage of a single battery cell 2 exceeding or falling below the maximum or minimum threshold voltage; the state where battery cell 1 or single battery cell 2 is overcharged or over-discharged; the state where the current of battery cell 1 or single battery cell 2 exceeds the maximum threshold current; and the state where the temperature of battery cell 1 or single battery cell 2 exceeds or falls below the maximum or minimum threshold temperature. Since this invention does not define abnormal states, various other states that reduce the safety of the power supply can also be determined as abnormal states.

[0052] The control circuit 7 includes a detection unit 16 for detecting abnormal states. The detection unit 16 detects an abnormal state and switches the switching element 10 from open to closed, thus blowing the fuse element 4 of the SCP3. In an abnormal state, the control circuit 7 uses the voltage detection circuit 8 to detect the voltage of the single battery 2, and the selection circuit 9 selects the switching element 10 to switch from open to closed. Figure 1 The control circuit 7 includes: an AFE (analog front end) 13, which detects the voltage, current, temperature, etc. of the battery cell 1 and each individual cell 2, converts them into digital signals and outputs them; an MPU (microprocessor unit) 14, which processes the digital signals output from the AFE 13; and an overcharge detection unit 15, which detects the voltage of the battery cell 1 to detect overcharge.

[0053] The AFE (Analog Front End) 13 includes a voltage detection circuit 8 for detecting the voltage of each individual cell 2, and the MPU (Microprocessor Unit) 14 includes a voltage detection circuit 8 for detecting the total voltage of the battery cells 1. The detection unit 16 can compare the individual cell voltages of the individual cells 2 detected by the AFE 13 and the total voltage of the battery cells 1 detected by the MPU 14 with a threshold value to determine an anomaly. Furthermore, the detection unit 16 can also detect the temperature of the battery cells 1 or the individual cells 2, and compare the detected temperature with a threshold value to determine an abnormal state. Figure 1 The detection unit 16 shown includes a temperature sensor 17, which detects the temperature of the battery cell 1 or the single battery 2.

[0054] The MPU14 calculates the remaining capacity of battery cell 1 and single cell 2 from the digital signal input from AFE13. It compares the remaining capacity, the detection voltage, and the threshold to determine the abnormal state. If the abnormal state is determined, it outputs the turn-on voltage to the gate of the switching element 10. Figure 1 The power supply 100 uses an n-channel FET in the switching element 10. The drain is connected to the heater 5 of SCP3 via diode 12, the source is connected to the battery cell 1, and the gate is connected to MPU14. Therefore, MPU14 inputs a voltage that is the turn-on voltage relative to the gate voltage of the source to the gate, switching the switching element 10 from off to on.

[0055] MPU14 includes a selection circuit 9 that selects and switches the first, second, and third switching elements 10a, 10b, and 10c from off to on based on the single-cell voltage of battery cell 1. For example, the selection circuit 9 switches the first switching element 10a from off to on when the single-cell voltage is in the range of 3.2 to 4.35V, switches the second switching element 10b from off to on when the single-cell voltage is in the range of 2.5 to 3.5V, and switches the third switching element 10c from off to on when the single-cell voltage is in the range of 1.9 to 2.6V. In abnormal conditions, in order to switch at least one switching element 10 from off to on, the selection circuit 9 sets both the first switching element 10a and the second switching element 10b to on state at a timing that causes the switching element 10 to switch from the first switching element 10a to the second switching element 10b as the single-cell voltage gradually decreases. In abnormal conditions, it reliably sets any switching element 10 to on state. The power supply 100 described above has the following advantages: In abnormal conditions, it can reliably turn on a certain switching element 10, cutting off the current in SCP3. Each switching element 10 connects a diode 12 in series, thus turning on multiple switching elements 10. Through the multiple switching elements 10 that are switched on, multiple different voltage terminals 11 are connected to the heater 5 of SCP3, but in this state, only one different voltage terminal 11 supplies power to SCP3. When multiple switching elements 10 are on, they connect the positive and negative sides of the single battery 2, but the diode 12 cuts off the discharge current of the single battery 2, preventing short-circuit current from flowing.

[0056] Figure 1 In addition to MPU14, the power supply 100 also includes an overcharge detection unit 15 that detects overcharging of battery cell 1, and the current is cut off by SCP3. The overcharge detection unit 15 detects the total voltage of battery cell 1 and switches the first switching element 10a from off to on. Since the overcharge detection unit 15 detects overcharging of battery cell 1, and therefore the single-cell voltage is high in this state, the overcharge detection unit 15 switches the first switching element 10a from off to on. Thus, the first switching element 10a receives an on-gate voltage from both MPU14 and the overcharge detection unit 15, switching from off to on. Because the power supply 100 switches the first switching element 10a from off to on by both MPU14 and the overcharge detection unit 15, even when AFE13 and MPU14 are not operating normally, the overcharge detection unit 15 has the advantage of being able to switch the first switching element 10a from off to on and have the charging current cut off by SCP3.

[0057] and then, Figure 1The power supply 100 is connected in series with the output side of the battery cell 1 to a discharge switch element 19 that cuts off the discharge current and a charging switch element 18 that cuts off the charging current. The discharge switch element 19 and the charging switch element 18 are controlled to be on and off by the AFE 13. When the detected voltage of the battery cell 1 or the single battery 2 is lower than the minimum voltage, the AFE 13 switches the discharge switch element 19 from on to off to cut off the discharge current. When the voltage is higher than the maximum voltage, the AFE 13 switches the charging switch element 18 from on to off to cut off the charging current.

[0058] Industrial availability

[0059] The present invention is a power supply with a battery cell, particularly with an SCP (Self-Control Protector) on the output side of the battery cell, which is suitable for power supplies that cut off the current by the SCP in case of an abnormality.

[0060] -Explanation of Figure Markers-

[0061] 100… power supply

[0062] 1… Battery cell

[0063] 2…Single battery

[0064] 3…SCP

[0065] 4…fuse element

[0066] 5… heaters

[0067] 6…Switch

[0068] 7…Control Circuit

[0069] 8…Voltage detection circuit

[0070] 9…Selection Circuit

[0071] 10…Switching elements

[0072] 10a…First switching element

[0073] 10b…Second Switching Element

[0074] 10c…Third switching element

[0075] 11…Different voltage terminals

[0076] 11a…First different voltage terminal

[0077] 11b…Second different voltage terminal

[0078] 11c…Third different voltage terminal

[0079] 12… Diode

[0080] 13…AFE

[0081] 14…MPU

[0082] 15…Overcharge Detection Department

[0083] 16… Testing Department

[0084] 17…Temperature sensor

[0085] 18… Charging switch element

[0086] 19…Discharge switch element.

Claims

1. A power source, comprising: Battery cell; The self-control protector SCP is connected in series with the battery cell and cuts off the charging and discharging current in abnormal conditions. A switch is used to connect the SCP to the battery cell; and The control circuit controls the switching on and off of the switch. The battery unit comprises multiple individual cells connected in series. The SCP possesses: A fuse element is connected in series on the output side of the battery cell; and A heater, connected to the battery cell, heats up using Joule heating, thereby melting the fuse element. The switch includes: Multiple switching elements, one terminal of which is connected to the heater, and another terminal of which is connected to multiple terminals with different voltages (different from the voltage of the battery cell). The control circuit includes: A voltage detection circuit detects the voltage of the battery cell or the single battery cell; and The selection circuit selects the switching element to be switched to the ON state based on the voltage detected by the voltage detection circuit. In abnormal conditions, the selection circuit selects the switching element to be switched to the ON state. When the switch is in the ON state, it connects the battery cell to the heater and melts the fuse element.

2. The power supply according to claim 1, wherein, The control circuit includes a detection unit for detecting abnormal states. When the detection unit detects an abnormal state, it sets the switching element to the ON state and melts the fuse element.

3. The power supply according to claim 2, wherein, The detection unit includes: Simulate the front-end AFE to detect the voltage of each of the individual cells; and The microprocessor unit (MPU) is used to detect the total voltage of the battery cell. The voltage of a single cell detected by the AFE and the total voltage of the battery cells detected by the MPU are compared with a threshold to determine anomalies.

4. The power supply according to claim 2 or 3, wherein, The detection unit includes an overcharge detection unit for detecting overcharging of the battery cell. The overcharge detection unit detects overcharging of the battery cell and blows the fuse element of the SCP.

5. The power supply according to any one of claims 2 to 4, wherein, The detection unit detects the temperature of the battery cell or the single battery and compares the detected temperature with a threshold to determine an abnormal state.

6. The power supply according to any one of claims 1 to 5, wherein, A diode is connected in series with each of the switching elements in the energizing direction of the switching element.

7. The power supply according to any one of claims 1 to 6, wherein, The switching element is a FET.

Images