A battery management circuit for a multi-output intrinsically safe power supply

Abstract

This invention discloses a battery management circuit for a multi-output intrinsically safe power supply, comprising: an external power input terminal P1 and a battery input terminal P4; a first relay RL1 for connecting the external power input terminal and the management circuit input terminal; a second relay RL2 for connecting the battery input terminal and the management circuit input terminal; a third relay RL3 for connecting the external battery input terminal and the external discharge resistor interface P2; a fourth relay RL4 for connecting the external power input terminal and the positive terminal of the battery; a battery voltage sampling circuit, consisting of a first voltage divider resistor R53 and a second voltage divider resistor R54 connected in series; a charging current detection circuit for detecting the battery charging current; and a discharging current detection circuit for detecting the battery discharging current. This multi-output intrinsically safe power supply battery management circuit can automatically switch power supply paths during use, achieving automatic control of charging and discharging. It meets intrinsic safety requirements even in hazardous environments and is suitable for widespread use.

Description

Technical Field

[0001] This invention relates to the field of battery control technology, and in particular to a battery management circuit for a multi-output intrinsically safe power supply. Background Technology

[0002] In hazardous working environments such as coal mines and chemical plants where explosive gases are present, intrinsically safe power supplies are key supporting devices to ensure the stable operation of on-site monitoring and control equipment. These power supplies are required to ensure that the electrical energy output by the circuit will not ignite the surrounding explosive medium under any fault condition, thus requiring strict energy management of the power supply circuit.

[0003] Currently, most intrinsically safe power supplies with backup batteries adopt a single-output structure, which cannot meet the needs of multiple devices to be powered at the same time. Moreover, most existing battery management circuits only have basic charge and discharge protection functions, and it is difficult to achieve intelligent automatic switching of the path according to battery voltage, ambient temperature and external power supply status. Once a short circuit or other sparking phenomenon occurs, it will cause an explosion, which cannot meet the intrinsic safety performance requirements of hazardous environments.

[0004] Therefore, there is an urgent need for a multi-output battery management circuit with high safety. Summary of the Invention

[0005] The purpose of this invention is to solve the above-mentioned problems by providing a battery management circuit that can automatically switch power supply paths, realize automatic charge and discharge control, and meet intrinsic safety requirements even in hazardous environments.

[0006] To achieve the above objectives, the technical solution of the present invention is: a battery management circuit for a multi-output intrinsically safe power supply, comprising: External power input terminal P1 and battery input terminal P4; The first relay RL1 is used to connect the external power input terminal to the management circuit input terminal; The second relay RL2 is used to connect the battery input terminal and the management circuit input terminal; The third relay RL3 is used to connect the external battery input terminal and the external discharge resistor interface P2. The fourth relay RL4 is used to connect the external power input terminal to the positive terminal of the battery; The first switching transistor Q2 has its output terminal connected to the coil of the first relay and is used to control the on and off state of the first relay. The second switching transistor Q1 has its output terminal connected to the coil of the second relay and is used to control the on and off state of the second relay. The third switch Q8 has its output connected to the coil of the third relay and is used to control the on / off state of the third relay. The fourth switching transistor Q3 has its output terminal connected to the coil of the fourth relay and is used to control the on / off state of the fourth relay. Multiple optocouplers, whose output sides are respectively connected to the control stage of each switching transistor, and whose input sides are used to receive control signals from the microcontroller; An ideal diode circuit is connected between the output terminal of the fourth relay and the battery terminal; The battery voltage sampling circuit is composed of a first voltage divider resistor R53 and a second voltage divider resistor R54 connected in series. It is connected to the positive terminal of the battery and ground, and outputs the battery voltage detection signal at the midpoint. The charging current detection circuit includes a first sampling resistor R32 and a first current detection amplifier U21, which is used to detect the battery charging current. The discharge current detection circuit includes a second sampling resistor R18 and a second current detection amplifier U13, which are used to detect the battery discharge current. The temperature sensor interface CN2 is used to connect a digital temperature sensor.

[0007] Preferably, the ideal diode circuit includes: The drain of the P-channel MOSFET Q4 is connected to the output terminal of the fourth relay, and the drain is connected to the positive terminal of the battery through the current sampling resistor R32. The emitters of the fifth switch Q5 and the sixth switch Q7 are connected to the drain and source of Q4, respectively. The first pull-down resistor R77 and the second pull-down resistor R78 are connected to the common output terminal and the gate of the P-channel MOSFET Q4, respectively.

[0008] Preferably, the first switch Q2, the second switch Q1, the third switch Q8 and the fourth switch Q3 are all NPN transistors.

[0009] Preferably, it also includes multiple Schottky diodes D1, D2, D3, and D4, which are connected in series in the output path of each relay to prevent current backflow.

[0010] Preferably, the Schottky diodes are divided into two stages. The anodes of the first Schottky diodes D1 and D2 are connected to the output terminals of the first relay RL1 and the second relay RL2, respectively, and their cathodes are connected to the DC-DC input terminal of the management circuit.

[0011] Preferably, the first sampling resistor R18 of the charging current detection circuit is connected in series between the output terminal of the fourth relay RL4 and the positive terminal of the battery; the second sampling resistor R32 of the discharging current detection circuit is connected in series between the negative terminal of the battery and ground.

[0012] Preferably, the first current sense amplifier U21 and the second current sense amplifier U13 are both INA210AIDCKR type high-side current sense amplifiers.

[0013] Preferably, the temperature sensor interface CN2 is a three-pin interface, wherein the first pin is the data line DQ, the second pin is ground GND, and the third pin is the power supply positive V+, which is used to connect to the DS18B20 digital temperature sensor.

[0014] Preferably, it also includes multiple anti-reverse-feed diodes D6, D7, D9, D10, D11, and D8, which are connected in parallel across the coil of each relay.

[0015] Preferred options also include: DC / DC conversion circuit, used to convert input power into a first DC voltage, with the external power input terminal connected to the first DC voltage; At least one intrinsically safe output circuit is connected to the system output terminal of the management circuit to output a voltage-limited and current-limited power supply that meets intrinsic safety requirements.

[0016] This invention discloses a battery management circuit for a multi-output intrinsically safe power supply, comprising: an external power input terminal P1 and a battery input terminal P4; a first relay RL1 for connecting the external power input terminal and the management circuit output terminal; a second relay RL2 for connecting the battery input terminal and the management circuit output terminal; a third relay RL3 for connecting the external battery input terminal and the external discharge resistor interface P2; a fourth relay RL4 for connecting the external power input terminal and the battery positive terminal; a battery voltage sampling circuit, consisting of a first voltage divider resistor R53 and a second voltage divider resistor R54 connected in series; a charging current detection circuit for detecting the battery charging current; and a discharging current detection circuit for detecting the battery discharging current. Compared with the prior art, this multi-output intrinsically safe power supply battery management circuit has the beneficial effect of automatically switching power supply paths during use, realizing automatic control of charging and discharging, and meeting intrinsic safety requirements even in hazardous environments. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall principle of the battery management circuit of the present invention.

[0018] Figure 2 This is a circuit diagram showing the connection between the external power supply and the battery input terminal in this invention.

[0019] Figure 3 This is a circuit diagram of the connection of the first relay in this invention.

[0020] Figure 4 This is a circuit diagram showing the connection of the second relay in this invention.

[0021] Figure 5 This is a circuit diagram showing the connection of the third relay in this invention.

[0022] Figure 6This is a circuit diagram showing the connection between the first relay and the ideal diode in this invention.

[0023] Figure 7 This is a circuit diagram of the battery voltage sampling circuit in this invention.

[0024] Figure 8 This is a circuit diagram for the charging current detection in this invention.

[0025] Figure 9 This is a circuit diagram for detecting the discharge current in this invention.

[0026] Figure 10 This is a circuit diagram for temperature acquisition in this invention.

[0027] Figure 11 This is a circuit diagram of the DC-DC conversion in this invention.

[0028] Figure 12 This is a circuit diagram of the DC-DC conversion control circuit in this invention.

[0029] Figure 13 This is a circuit diagram of the 24V intrinsically safe output circuit in this invention.

[0030] Figure 14 This is a circuit diagram of the 18V intrinsically safe output circuit in this invention.

[0031] Figure 15 This is a circuit diagram of the 12V intrinsically safe output circuit in this invention.

[0032] Figure 16 This is a circuit diagram of the three-channel output current acquisition circuit in this invention. Detailed Implementation

[0033] The present invention will now be described in further detail with reference to the accompanying drawings. The drawings are simplified schematic diagrams, illustrating only the basic structure of the invention in a schematic manner, and therefore only show the components relevant to the invention.

[0034] Please refer to Figure 1-9 A battery management circuit for a multi-output intrinsically safe power supply, comprising: External power input terminal P1 and battery input terminal P4; automatic / controlled switching between 28V DC input and 28V battery; The first relay RL1 is used to connect the external power input terminal to the management circuit output terminal (+DC_OUT). The second relay RL2 is used to connect the battery input terminal and the management circuit output terminal; The third relay RL3 is used to connect the external battery input terminal and the external discharge resistor interface P2. The fourth relay RL4 is used to connect the external power input terminal to the positive terminal of the battery (BAT+). The first relay RL1, the second relay RL2, the third relay RL3, and the fourth relay RL4 isolate the input, output, battery power supply, and external discharge load.

[0035] The first switching transistor Q2 has its output terminal connected to the coil of the first relay and is used to control the on and off state of the first relay. The second switching transistor Q1 has its output terminal connected to the coil of the second relay and is used to control the on and off state of the second relay. The third switch Q8 has its output connected to the coil of the third relay and is used to control the on / off state of the third relay. The fourth switching transistor Q3 has its output terminal connected to the coil of the fourth relay and is used to control the on / off state of the fourth relay. Multiple optocouplers, whose output sides are respectively connected to the control stage of each switching transistor, and whose input sides are used to receive control signals from the microcontroller; An ideal diode circuit is connected between the output terminal of the fourth relay and the battery terminal; The battery voltage sampling circuit consists of a first voltage divider resistor R53 and a second voltage divider resistor R54 connected in series. It is connected to the positive terminal of the battery and ground, and outputs the battery voltage detection signal (BAT_VOL) at the midpoint. The charging current detection circuit includes a first sampling resistor R32 and a first current detection amplifier U21, which is used to detect the battery charging current. The discharge current detection circuit includes a second sampling resistor R18 and a second current detection amplifier U13, which are used to detect the battery discharge current. The temperature sensor interface CN2 is used to connect a digital temperature sensor.

[0036] This circuit outputs control signals through a microcontroller, which are then isolated by an optocoupler to drive each switching transistor, thereby controlling the on / off state of four relays. It can switch between multiple working modes, including external power supply, battery power supply, battery charging, and battery discharging maintenance. The ideal diode replaces the traditional power diode, which can significantly reduce the forward voltage drop and improve the overall conversion efficiency of the circuit. The multi-parameter detection circuit of voltage, current and temperature can collect the battery's operating status parameters in real time, providing accurate data support for the logic control of battery management. In conjunction with the intrinsically safe output circuit at the back end, it can output multiple power supplies that meet intrinsic safety requirements, which is suitable for application scenarios such as underground coal mines where explosion-proof safety is required.

[0037] Please refer to this again. Figure 1In this embodiment, the power supply and battery serve the same purpose: to provide power to subsequent circuits. The battery is charged through the power supply terminal, an ideal diode, and a charging current detection circuit. When the power supply terminal is de-energized, the battery and the power supply control circuit provide power to the subsequent circuits. When the battery is depleted, the power supply control circuit cuts off the power. The battery power supply control circuit is... Figure 4 As shown; When the power supply is continuous, the battery can be charged not only through the ideal diode and charging current detection circuit, but also directly through the DC-DC conversion circuit. Because the power supply is continuous, the battery remains fully charged for extended periods. To ensure battery lifespan, a discharge control circuit periodically discharges the battery. This discharge control circuit is... Figure 5 As shown; Therefore, both the power supply control circuit and the discharge control circuit can protect the battery and help extend its service life.

[0038] In this embodiment, the ideal diode circuit includes: The source of the P-channel MOSFET Q4 is connected between the output terminal of the fourth relay and the battery terminal, and the drain is connected to the positive terminal of the battery through the current sampling resistor R32. The emitters of the fifth switch Q5 and the sixth switch Q7 are connected to the drain and source of Q4, respectively. Both the fifth switch Q5 and the sixth switch Q7 are PNP type transistors. The first pull-down resistor R77 and the second pull-down resistor R78 are connected to the common output terminal and the gate of the P-channel MOSFET Q4, respectively.

[0039] The first switch Q2, the second switch Q1, the third switch Q8 and the fourth switch Q3 are all NPN transistors (SS8050). Their bases are connected to the output side of the optocoupler through a current-limiting resistor, their emitters are grounded, and their collectors are connected to one end of the coil of the corresponding relay.

[0040] It also includes multiple Schottky diodes D1, D2, D3, and D4, which are connected in series in the output path of each relay to prevent current backflow; Please refer to this again. Figure 3-4 The Schottky diodes are divided into two stages. The anodes of the first Schottky diodes D1 and D2 are connected to the output terminals of the first relay RL1 and the second relay RL2, respectively, and their cathodes are connected to the DC-DC input terminal of the management circuit.

[0041] Please refer to this again. Figure 8 The first sampling resistor R18 of the charging current detection circuit is connected in series between the output terminal of the fourth relay RL4 and the positive terminal of the battery; the second sampling resistor R32 of the discharging current detection circuit is connected in series between the negative terminal of the battery and ground.

[0042] As a preferred embodiment, both the first current sensing amplifier U21 and the second current sensing amplifier U13 are INA210AIDCKR type high-side current sensing amplifiers.

[0043] Please refer to Figure 10 The temperature sensor interface CN2 is a three-pin interface, where the first pin is the data line DQ, the second pin is ground GND, and the third pin is the power supply positive V+, used to connect to the DS18B20 digital temperature sensor.

[0044] Based on the above embodiments, it also includes multiple anti-reverse-feed diodes D6, D7, D9, D10, D11, and D8, which are connected in parallel across the coil of each relay.

[0045] Please refer to Figure 11-12 It also includes: DC / DC (AC-DC) converter circuit is used to convert the input power supply into a first DC voltage, and the external power supply input terminal is connected to the first DC voltage; At least one intrinsically safe output circuit is connected to the system output terminal of the management circuit to output a voltage-limited and current-limited power supply that meets intrinsic safety requirements.

[0046] Please refer to Figure 13-16 In this embodiment, the intrinsically safe output circuit has three channels: 24V intrinsically safe output, 18V intrinsically safe output, and 12V intrinsically safe output. Each intrinsically safe output has an independent voltage and current limiting circuit and an output current sampling circuit, which can monitor and adjust the output parameters individually to ensure that each output meets the intrinsically safe explosion-proof requirements. The entire circuit realizes reliable switching between external power supply and backup battery through battery management. With the multi-channel intrinsically safe output architecture, it can provide a continuous, stable, safe and reliable power supply for downhole equipment that requires intrinsically safe power supply, and meet the usage needs of multiple intrinsically safe power supplies of different voltage levels.

[0047] The power supply principle in this invention is as follows: When the external power supply is input normally, the microcontroller controls the first relay RL1 to close and the second relay RL2 to open, so that the external power supply directly supplies power to the intrinsically safe output circuit at the back end. At the same time, according to the remaining power status of the battery, the microcontroller controls the fourth relay RL4 to close, so that the external power supply can charge the battery through the analog diode circuit. During the charging process, the charging current detection circuit monitors the charging current in real time and adjusts the charging status according to the battery charging stage to avoid overcharging.

[0048] When the external power supply fails or the voltage drops below a set threshold, the microcontroller immediately controls the first relay RL1 to disconnect and the second relay RL2 to engage, switching power supply to the intrinsically safe output circuit from the battery to ensure continuous power supply. When maintenance discharge of the battery is required, the microcontroller controls the third relay RL3 to engage, connecting the battery to the external discharge resistor at the external discharge resistor interface P2 for controlled discharge. During discharge, the discharge current is monitored in real time by a discharge current detection circuit to ensure safety. The entire switching control process achieves electrical isolation between the microcontroller control side and the power circuit through an optocoupler, ensuring stable transmission of control signals and improving circuit safety performance. This power supply can even be used to power equipment in explosive environments.

[0049] The battery power supply principle is as follows: When the battery is connected to the circuit for external power supply, the battery voltage sampling circuit continuously collects the battery terminal voltage and transmits the divided detection signal to the microcontroller. The microcontroller determines the remaining battery power based on the collected voltage signal. The temperature sensor collects the battery temperature during operation and uploads the temperature data to the microcontroller in real time. When the battery temperature exceeds the safe operating range, the microcontroller will promptly trigger a protection action to cut off the power supply output. The discharge current detection circuit collects the current value of the discharge circuit in real time. When the discharge current exceeds the limit range or an output short circuit occurs, the microcontroller can quickly control the relay to disconnect the output, realizing overcurrent and short circuit protection. Combined with the dual current limiting and voltage limiting of the intrinsically safe output circuit at the back end, it ensures that the entire output circuit always meets the intrinsic safety requirements.

[0050] The protection logic of this battery management circuit is as follows: When an output overcurrent or short-circuit fault occurs, the intrinsically safe output circuit at the back end first performs primary protection by limiting the voltage and current, quickly restricting the fault current. If the primary protection fails to effectively cut off the fault, the microcontroller, after acquiring the overcurrent or short-circuit current signal, will immediately control the relay of the corresponding output path to disconnect, and simultaneously cut off the power output on the management side, thus achieving secondary protection. The voltage drop difference logic compares the voltage difference between the output terminal of the management circuit and the intrinsically safe output terminal. If the difference exceeds the normal range, it is determined to be an output fault. This, combined with the overcurrent signal, achieves dual redundancy judgment, avoids false operation, and improves protection reliability. After the fault protection is completed, the circuit will only return to normal output state when the fault is cleared and the reset signal is valid.

[0051] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A battery management circuit for a multi-output intrinsically safe power supply, characterized in that, include: External power input terminal P1 and battery input terminal P4; The first relay RL1 is used to connect the external power input terminal to the management circuit input terminal; The second relay RL2 is used to connect the battery input terminal and the management circuit input terminal; The third relay RL3 is used to connect the external battery input terminal and the external discharge resistor interface P2. The fourth relay RL4 is used to connect the external power input terminal to the positive terminal of the battery; The first switching transistor Q2 has its output terminal connected to the coil of the first relay and is used to control the on and off state of the first relay. The second switching transistor Q1 has its output terminal connected to the coil of the second relay and is used to control the on and off state of the second relay. The third switch Q8 has its output connected to the coil of the third relay and is used to control the on / off state of the third relay. The fourth switching transistor Q3 has its output terminal connected to the coil of the fourth relay and is used to control the on / off state of the fourth relay. Multiple optocouplers, whose output sides are respectively connected to the control stage of each switching transistor, and whose input sides are used to receive control signals from the microcontroller; An ideal diode circuit is connected between the output terminal of the fourth relay and the battery terminal; The battery voltage sampling circuit is composed of a first voltage divider resistor R53 and a second voltage divider resistor R54 connected in series. It is connected to the positive terminal of the battery and ground, and outputs the battery voltage detection signal at the midpoint. The charging current detection circuit includes a first sampling resistor R32 and a first current detection amplifier U21, which is used to detect the battery charging current. The discharge current detection circuit includes a second sampling resistor R18 and a second current detection amplifier U13, which are used to detect the battery discharge current. The temperature sensor interface CN2 is used to connect a digital temperature sensor.

2. The battery management circuit for a multi-output intrinsically safe power supply according to claim 1, characterized in that, The ideal diode circuit includes: The drain of the P-channel MOSFET Q4 is connected to the output terminal of the fourth relay, and the drain is connected to the positive terminal of the battery through the current sampling resistor R32. The emitters of the fifth switch Q5 and the sixth switch Q7 are connected to the drain and source of Q4, respectively. The first pull-down resistor R77 and the second pull-down resistor R78 are connected to the common output terminal and the gate of the P-channel MOSFET Q4, respectively.

3. The battery management circuit for a multi-output intrinsically safe power supply according to claim 1, characterized in that, The first switch Q2, the second switch Q1, the third switch Q8 and the fourth switch Q3 are all NPN transistors.

4. The battery management circuit for a multi-output intrinsically safe power supply according to claim 1, characterized in that, It also includes multiple Schottky diodes D1, D2, D3, and D4, which are connected in series in the output path of each relay to prevent current backflow.

5. The battery management circuit for a multi-output intrinsically safe power supply according to claim 4, characterized in that, The Schottky diodes are divided into two stages. The anodes of the first Schottky diodes D1 and D2 are connected to the output terminals of the first relay RL1 and the second relay RL2, respectively, and their cathodes are connected to the DC-DC input terminal of the management circuit.

6. The battery management circuit for a multi-output intrinsically safe power supply according to claim 1, characterized in that, The first sampling resistor R18 of the charging current detection circuit is connected in series between the output terminal of the fourth relay RL4 and the positive terminal of the battery; the second sampling resistor R32 of the discharging current detection circuit is connected in series between the negative terminal of the battery and ground.

7. The battery management circuit for a multi-output intrinsically safe power supply according to claim 1, characterized in that, The first current sense amplifier U21 and the second current sense amplifier U13 are both INA210AIDCKR type high-side current sense amplifiers.

8. The battery management circuit for a multi-output intrinsically safe power supply according to claim 1, characterized in that, The temperature sensor interface CN2 is a three-pin interface, where the first pin is the data line DQ, the second pin is ground GND, and the third pin is the power supply positive V+, used to connect to the DS18B20 digital temperature sensor.

9. The battery management circuit for a multi-output intrinsically safe power supply according to claim 1, characterized in that, It also includes multiple anti-reverse-feed diodes D6, D7, D9, D10, D11, and D8, which are connected in parallel across the coil of each relay.

10. The battery management circuit for a multi-output intrinsically safe power supply according to claim 1, characterized in that, Also includes: DC / DC conversion circuit, used to convert input power into a first DC voltage, with the external power input terminal connected to the first DC voltage; At least one intrinsically safe output circuit is connected to the system output terminal of the management circuit to output a voltage-limited and current-limited power supply that meets intrinsic safety requirements.

Images