A battery reverse polarity protection circuit

Abstract

This utility model relates to the technical field of battery charging circuit protection, and discloses a battery reverse polarity protection circuit, including an MIO module. The L1 terminal of the MIO module is connected to a 24V power supply line, and the M terminal is connected to a 0V power supply line. The MIO module is configured with at least two signal input terminals and at least two control output terminals (KO, K1). The signal input terminals are used to receive battery reverse polarity detection signals and low voltage disconnection detection signals, and the control output terminals are used to output protection control commands. The MIO module processes the received signals and generates corresponding control commands through internal logic circuits. This utility model, through the collaborative construction of a battery reverse polarity protection circuit consisting of an MIO module, a battery reverse polarity and low voltage detection circuit, and an ER module, has significant technical advantages. It constructs a control system with the MIO module as the core, which receives and processes battery reverse polarity and low voltage disconnection signals, and accurately realizes circuit logic control.

Description

Technical Field

[0001] This utility model relates to the technical field of battery charging circuit protection, and more specifically, to a battery reverse polarity protection circuit. Background Technology

[0002] Batteries in DC circuits are one of the most crucial core components in chargers. Batteries cannot directly use AC power; they are rectified into DC power through thyristors in an AC circuit. When charging batteries (such as lead-acid and lithium-ion batteries), reverse connection can generate a large current discharge, leading to overheating, electrolyte boiling, or even explosion. Sensitive electronic components, rectifier diodes, and capacitors inside the charger are easily burned out by reverse current during reverse connection.

[0003] There are generally two existing solutions: one is to use a traditional series diode and fuse, where the diode blocks the reverse current and the fuse blows when there is an overcurrent; the other is to utilize the low internal resistance characteristic of a P-MOS transistor.

[0004] Reference Figure 1-2 The diagram shows a traditional series diode + fuse connection. The diode + fuse scheme is currently cumbersome to maintain, requiring frequent fuse replacements, and the diode is prone to overheating and damage under high current conditions. While the advantages of this circuit are obvious—simple, practical, and low-cost—it has several drawbacks. First, the diode has a forward voltage drop ranging from 0.7 to 3V, which may be unsuitable for low voltage applications, potentially leading to insufficient load voltage after voltage division. Second, while the diode has a high withstand voltage, its overcurrent capability is limited; for example, the maximum forward continuous current of a 4007 diode is approximately 1A.

[0005] Reference Figure 3-4 The diagram shows a wiring schematic utilizing the low internal resistance of a P-MOS transistor. The P-MOS transistor should be connected to the positive terminal of the power supply, and a parasitic diode should be connected in series in the forward direction in the circuit. Its working principle utilizes the unidirectional conductivity of the diode. This application should be distinguished from the switching application of P-MOS transistors. The advantage is that the on-state voltage drop is small because the on-state resistance of the MOS transistor is very small, so the voltage drop is very small. The heat dissipation MOS transistor solution is better than the diode solution. Although it reduces losses, it lacks intelligent detection and status feedback, and users cannot know the cause of the fault in time. Utility Model Content

[0006] The purpose of this utility model is to provide a battery reverse polarity protection circuit. The battery reverse polarity protection circuit, which is composed of an MIO module, a battery reverse polarity and low voltage detection circuit, and an ER module, has significant technical advantages. It constructs a control system with the MIO module as the core, which receives and processes battery reverse polarity and low voltage disconnection signals, and accurately realizes circuit logic control, aiming to solve the problems in the prior art.

[0007] This invention is implemented as follows: a battery reverse polarity protection circuit includes an MIO module. The L1 terminal of the MIO module is connected to a 24V power supply line, and the M terminal is connected to a 0V power supply line. The MIO module is configured with at least two signal input terminals and at least two control output terminals (KO, K1). The signal input terminals are used to receive battery reverse polarity detection signals and low voltage disconnection detection signals, and the control output terminals are used to output protection control commands. The MIO module processes the received signals and generates corresponding control commands through internal logic circuits.

[0008] Furthermore, the protection circuit also includes a battery reverse polarity detection circuit. This detection circuit has a detection line labeled BATTERY REVERSE POLARITY. The coils of relays KA1 and KA2 are connected in series in the battery reverse polarity detection circuit. One end of the coil of relay KA1 is connected to the positive terminal of the battery, and the other end is connected to one end of the coil of relay KA2. The other end of the coil of relay KA2 is connected to the first signal input terminal of the MIO module. The normally open contacts of relays KA1 and KA2 are connected in series to the second signal input terminal of the MIO module, forming a reverse polarity signal feedback loop.

[0009] Furthermore, the protection circuit also includes a battery low voltage disconnection detection line, labeled BATTERYLOW VOLTAGE DISCONNECTED. The detection line includes a series voltage divider resistor network and a voltage comparator. The input of the voltage divider resistor network is connected to the battery pack output, and the output is connected to the non-inverting input of the voltage comparator. The inverting input of the voltage comparator is connected to a reference voltage source, and the output is connected to the third signal input of the MIO module via an optocoupler.

[0010] Furthermore, the protection circuit also includes an ER module. The input terminal of the ER module is provided with three phase wire terminals (L1, L2, L3) and one neutral wire terminal (N), which are respectively connected to the three-phase live wire and neutral wire of AC380V, 50Hz, 3P+N AC power. The output terminal of the ER module is provided with a positive terminal and a negative terminal for outputting DC voltage.

[0011] Furthermore, the positive terminal of the ER module is connected in series with the PJ1 fuse and then splits into two paths: one path is connected to the input terminal of the power conversion and output module, and the other path is connected to the battery pack charging control circuit; the negative terminal of the ER module is directly connected to the negative input terminal of the power conversion and output module and the negative terminal of the battery pack charging control circuit.

[0012] Furthermore, the protection circuit also includes a TP1 module, which has power input terminals (V+, V-) connected to a 24V power supply line and a 0V power supply line respectively; the RS485 interfaces (A, B) of the TP1 module are connected to the RS485 interfaces (A, B) of the MIO module and the RS485 interfaces (A, B) of the HMI respectively via shielded twisted-pair cables; the communication baud rate between the TP1 module and the MIO module is set to 9600bps, and the data format is 8 data bits, 1 stop bit, and no parity.

[0013] Furthermore, the HMI is equipped with power interfaces (24V, 0V) that are connected to the 24V power supply line and the 0V power supply line respectively; the RS485 interfaces (A, B) of the HMI are connected to the corresponding RS485 interfaces (A, B) of the TP1 module through shielded twisted pair cables; the HMI and the TP1 module use the Modbus RTU communication protocol for data interaction.

[0014] Furthermore, the power supply conversion and output module includes a QF1-OF conversion unit and a QF1-MX conversion unit; the input terminal of the QF1-OF conversion unit is connected to the output terminal of the ER module after passing through PJ1, and the output terminal (DC220V+, DC220V-) supplies power to the 220V DC load; the input terminal of the QF1-MX conversion unit is connected to the output terminal of the QF1-OF conversion unit, and the output terminal (DC24V+, DC24V-) is connected to the power supply terminals of the MIO module, TP1 module, HMI and relay coil respectively.

[0015] Furthermore, the protection circuit also includes a battery pack connection and protection line, which has a BAT+ terminal and a BAT- terminal, respectively connected to the positive and negative terminals of the battery pack; the BAT+ terminal is connected to the positive terminal of the load after being connected in series with the normally closed contact of the KA1 relay; the BAT- terminal is connected to the negative terminal of the load after being connected in series with the normally closed contact of the KA2 relay; the coil control terminals of the KA1 and KA2 relays are respectively connected to the KO and K1 control output terminals of the MIO module.

[0016] Furthermore, the 24V power supply line and the 0V power supply line use copper core wires with a cross-sectional area of ​​1.5mm² to form a star grounding network; the metal casing of all modules is connected to the protective grounding terminal (PE) through a grounding wire (cross-sectional area of ​​2.5mm²) to form grounding protection.

[0017] Compared with the prior art, the battery reverse polarity protection circuit provided by this utility model has the following beneficial effects: 1. The battery reverse polarity protection circuit, composed of the MIO module, battery reverse polarity and low voltage detection circuit, and ER module, has significant technical advantages. It constructs a control system centered on the MIO module, which receives and processes battery reverse polarity and low voltage disconnection signals to accurately implement circuit logic control. In the battery reverse polarity detection circuit, the cooperation between the KA1 and KA2 relays and the MIO module, along with the linkage of the low voltage disconnection detection circuit, enables real-time and accurate monitoring of battery status. The ER module converts AC to DC to power the system, adapting to different voltage requirements in conjunction with the power conversion module, ensuring component operation. The system formed by the various modules via the bus and power supply lines achieves battery reverse polarity detection protection and component coordination, effectively preventing battery abnormalities from affecting the system, ensuring power supply and system stability, and solving the problems of traditional circuits in accurately monitoring and protecting against and adapting to the power supply of multiple components. 2. An innovative detection and protection mechanism, utilizing the MIO module to process battery status signals, can quickly respond to reverse polarity or low voltage conditions, cutting off dangerous circuits, adjusting the load, protecting the battery and circuit system, and reducing the risk of equipment damage and downtime. In field installation, the openable design with clear module connections simplifies operation, eliminating the need for complex wiring and disassembly, avoiding direct connection to high-voltage circuits, reducing impact, and improving installation and maintenance efficiency and safety. Compared to traditional protection circuits, this invention achieves breakthroughs in status monitoring accuracy, system adaptability, and installation convenience, providing a reliable solution for the stable operation of battery-powered systems and promoting the efficient and safe application of related equipment in industrial and other scenarios. Attached Figure Description

[0018] Figure 1 This is a circuit diagram showing the correct wiring for diode + fuse polarity reverse connection protection. Figure 2 This is a circuit diagram for protection against incorrect wiring based on diode and fuse polarity reverse connection. Figure 3 This is a circuit diagram showing the correct wiring for P-MOS transistor reverse polarity protection. Figure 4 This is a circuit diagram for protection against incorrect wiring based on reverse polarity connection of a P-MOS transistor; Figure 5 This is a circuit diagram of a battery reverse polarity protection circuit proposed in this utility model. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0020] The implementation of this utility model will be described in detail below with reference to specific embodiments.

[0021] In the accompanying drawings of this embodiment, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that if terms such as "upper," "lower," "left," and "right" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this utility model. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0022] Reference Figure 5 As shown, a battery reverse polarity protection circuit includes an MIO module. The L1 terminal of the MIO module is connected to a 24V power supply line, and the M terminal is connected to a 0V power supply line. The MIO module is configured with at least two signal input terminals and at least two control output terminals (KO, K1). The signal input terminals are used to receive battery reverse polarity detection signals and low voltage disconnection detection signals, and the control output terminals are used to output protection control commands. The MIO module processes the received signals and generates corresponding control commands through internal logic circuits. It also includes a battery reverse polarity detection circuit, which has a detection line labeled BATTERY REVERSE POLARITY. The detection line has coils of KA1 relay and KA2 relay connected in series. One end of the coil of KA1 relay is connected to the positive terminal of the battery, and the other end is connected to one end of the coil of KA2 relay. The other end of the coil of KA2 relay is connected to the first signal input terminal of the MIO module. The normally open contacts of KA1 and KA2 relays are connected in series to the second signal input terminal of the MIO module to form a reverse polarity signal feedback loop. It also includes a battery low voltage disconnection detection circuit, which is labeled BATTERY LOW VOLTAGE DISCONNECTED. The detection circuit includes a series voltage divider resistor network and a voltage comparator. The input of the voltage divider resistor network is connected to the battery pack output, and the output is connected to the non-inverting input of the voltage comparator. The inverting input of the voltage comparator is connected to a reference voltage source, and the output is connected to the third signal input of the MIO module through an optocoupler. It also includes an ER module, whose input terminals have three phase wire terminals (L1, L2, L3) and one neutral wire terminal (N), which are respectively connected to the three-phase live wire and neutral wire of AC380V, 50Hz, 3P+N AC power; the output terminals of the ER module have positive and negative terminals for outputting DC voltage. It also includes a TP1 module, which has power input terminals (V+, V-) that connect to a 24V power supply line and a 0V power supply line, respectively; the RS485 interfaces (A, B) of the TP1 module are connected to the RS485 interfaces (A, B) of the MIO module and the RS485 interfaces (A, B) of the HMI via shielded twisted-pair cables, respectively; the communication baud rate between the TP1 module and the MIO module is set to 9600bps, and the data format is 8 data bits, 1 stop bit, and no parity; It also includes a battery pack connection and protection circuit, which has a BAT+ terminal and a BAT- terminal, connected to the positive and negative terminals of the battery pack respectively; the BAT+ terminal is connected to the positive terminal of the load after being connected in series with the normally closed contact of the KA1 relay; the BAT- terminal is connected to the negative terminal of the load after being connected in series with the normally closed contact of the KA2 relay; the coil control terminals of the KA1 and KA2 relays are connected to the KO and K1 control output terminals of the MIO module respectively. The battery reverse polarity protection circuit, constructed through the collaboration of the MIO module, the battery reverse polarity and low voltage detection circuit, and the ER module, has significant technical advantages, building a control system centered on the MIO module. The system receives and processes battery reverse polarity and low voltage disconnection signals, enabling precise circuit logic control. In the battery reverse polarity detection circuit, the cooperation between KA1 and KA2 relays and the MIO module, along with the linkage of the low voltage disconnection detection circuit, allows for real-time and accurate monitoring of battery status. The ER module converts AC to DC to power the system, adapting to different voltage requirements in conjunction with the power conversion module, ensuring component operation. The system formed by all modules via the bus and power supply lines achieves battery reverse polarity detection protection and component coordination, effectively preventing battery abnormalities from affecting the system, ensuring power supply and system stability, and solving the problems of traditional circuits in accurately monitoring and protecting components and adapting to multiple component power supplies.

[0023] In this embodiment, the positive terminal of the ER module is connected in series with the PJ1 fuse and then splits into two paths: one path is connected to the input terminal of the power conversion and output module, and the other path is connected to the battery pack charging control circuit; the negative terminal of the ER module is directly connected to the negative input terminal of the power conversion and output module and the negative terminal of the battery pack charging control circuit.

[0024] In this embodiment, the HMI is provided with power interfaces (24V, 0V) that are connected to the 24V power supply line and the 0V power supply line respectively; the RS485 interfaces (A, B) of the HMI are connected to the corresponding RS485 interfaces (A, B) of the TP1 module through shielded twisted pair cables; the HMI and the TP1 module use the Modbus RTU communication protocol for data interaction.

[0025] In this embodiment, the power conversion and output module includes a QF1-OF conversion unit and a QF1-MX conversion unit; the input terminal of the QF1-OF conversion unit is connected to the output terminal of the ER module after passing through PJ1, and the output terminal (DC220V+, DC220V-) supplies power to the 220V DC load; the input terminal of the QF1-MX conversion unit is connected to the output terminal of the QF1-OF conversion unit, and the output terminal (DC24V+, DC24V-) is connected to the power supply terminals of the MIO module, TP1 module, HMI and relay coil respectively.

[0026] In this embodiment, the 24V power supply line and the 0V power supply line use copper core wires with a cross-sectional area of ​​1.5mm² to form a star grounding network; the RS485 data bus uses twisted-pair shielded wire, with 120Ω terminating resistors connected in parallel at both ends; the metal casings of all modules are connected to the protective grounding terminal (PE) through a grounding wire (cross-sectional area of ​​2.5mm²) to form grounding protection.

[0027] The MIO module (model M-6016), as the core control unit, features digital input / output, signal processing, and logic control functions. It operates on a DC 24V voltage and, through its integrated control algorithm, processes input signals such as battery reverse polarity and low voltage disconnection, outputting control commands. Its input impedance is [X]Ω, and its output drive capability reaches [X]mA, meeting the requirements of subsequent relays, bus communication, and other loads.

[0028] Wiring and Connection: The module has M and L1 terminals. Terminal M connects to the 0V power supply circuit, and terminal L1 connects to the 24V power supply line, forming the module's DC power supply circuit. It is equipped with KO and K1 control output terminals for outputting control signals to drive external relays, indicator lights, and other loads. It also has corresponding digital input interfaces for connecting to battery reverse polarity detection and low voltage disconnection detection circuits, and for receiving status signals.

[0029] Battery reverse polarity detection circuit (labeled "BATTERY REVERSEPOLARITY"), components and connections: KA1 and KA2 relays connected in series in the circuit are selected from [specific relay model, such as Omron G2R-1 series], with a coil rated voltage of [X]V and contact capacity of [X]A. After the KA1 and KA2 relay coils are connected in series, one end is connected to the battery positive terminal detection circuit, and the other end is connected to the corresponding input terminal of the MIO module. The reverse polarity of the battery is detected by the change in the state of the relay contacts. When the battery polarity is normal, the relay coil is energized / de-energized (according to the circuit logic design), and the MIO module detects the corresponding level signal; if the battery polarity is reversed, the relay operates, the MIO module receives the abnormal signal, and triggers the protection logic.

[0030] Working principle: Utilizing the electromagnetic induction principle of relays, when the battery is connected with the correct polarity, the relay coil forms a logical current path, and the contacts remain in their initial state (normally open / normally closed); when connected with the reverse polarity, the direction of the coil current changes (or a normal current cannot be formed), the contacts actuate, and the MIO module identifies the abnormal signal according to the preset program, cuts off the dangerous circuit or issues an alarm command.

[0031] The battery low voltage disconnection detection circuit uses a voltage detection circuit (which can be assisted by a voltage divider resistor and a voltage comparator; the voltage divider resistor can be selected based on [specific resistor model, such as a 1206 surface mount resistor with a resistance value of [X] kΩ], and the voltage comparator model can be [such as an LM393]) to collect the battery voltage signal and connect it to the corresponding input interface of the MIO module. When the battery voltage is lower than a set threshold (such as [X]% of the battery's rated voltage, which can be set through internal parameters of the MIO module or adjusted by an external potentiometer), the voltage comparator output level changes. The MIO module detects this signal, determines that the battery is in a low voltage disconnection state, and executes corresponding control strategies, such as cutting off unnecessary loads and issuing alarm prompts.

[0032] The ER module converts input AC380V, 50Hz, 3P+N alternating current into power suitable for subsequent DC power supply circuits. Its input voltage range is compatible with [X]V-[X]V (to handle grid voltage fluctuations), and the output DC voltage accuracy is [X]%, with a conversion efficiency of up to [X]%. Internally, it employs high-frequency switching power supply technology, using rectification, filtering, and voltage regulation circuits to convert AC power into stable DC power, providing power to subsequent DC components (such as MIO modules and relay coils).

[0033] Wiring and subsequent connections: The ER module input side is connected to AC380V, 50HZ, 3P+N AC power. Phases A, B, and C are connected to the three-phase live wires, and the N wire is connected to the neutral wire. The output end is connected to the circuit including PJ1. PJ1 is selected as [specific fuse model, such as fast-blow fuse RT18-32 series, rated current [X]A, rated voltage [X]V], as an overcurrent protection device, connected in series between the ER module output and the subsequent DC circuit. When an overcurrent fault occurs in the circuit (such as a load short circuit), the fuse blows, cutting off the ER module output and protecting the subsequent DC circuit and equipment.

[0034] The TP1 module acts as a data interaction bridge, enabling data exchange between the MIO module and the HMI (Human Machine Interface). It supports RS485 bus communication, with configurable baud rates (e.g., 9600bps, 19200bps, etc.) and a maximum communication distance of [X]m (when conforming to RS485 bus specifications and using shielded twisted-pair cable). The module incorporates communication protocol conversion and data caching functions to adapt to the data format between the MIO module and the HMI, ensuring stable data transmission. It connects to the MIO module and HMI via the RS485 bus (RS485A, RS485B). On one side of the TP1 module, RS485 interface A connects to the RS485A terminal of the MIO module, and RS485B connects to the RS485B terminal. On the other side, the RS485 interface connects to the corresponding RS485 bus interface of the HMI, establishing a data transmission link and enabling the exchange of MIO module control data and battery status data between the TP1 and the HMI.

[0035] The HMI serves as a human-machine interface, allowing operators to view circuit operating status (such as battery voltage, reverse polarity, low voltage alarm status, etc.) and set system parameters (such as low voltage disconnection threshold, communication baud rate, etc.). The screen resolution is [X]×[X], employing a [touch / button] interaction method. It has a built-in communication protocol parsing program, is compatible with RS485 bus communication, and transmits and receives data with the TP1 module. The response time is less than [X] ms, ensuring real-time operation.

[0036] Interaction Logic: Operators send parameter setting commands via button / touch operation on the HMI interface. The commands are transmitted to the TP1 module via RS485 bus and then forwarded to the MIO module for execution. At the same time, the battery status and system operation data collected by the MIO module are transmitted to the HMI via the TP1 module and presented on the interface in the form of numerical displays, status indicator lights, curves and charts, etc., to facilitate monitoring and judgment by operators.

[0037] The power conversion and output module includes AC / DC conversion components (QF1-OF, QF1-MX) that convert AC380V to 220V / 24V. QF1-OF uses a specific AC / DC power module model, such as the Mean Well NDR series, with an input of AC380V and an output of DC220V, output power of [X]W, and conversion efficiency of [X]%; QF1-MX uses a corresponding DC / DC power module model, such as the Mean Well DRT series, with an input of DC220V and an output of DC24V, and an output current of [X]A. This module first converts the input AC380V three-phase AC power to DC220V, and then further converts it to DC24V, providing stable power to 220V and 24V components in the circuit (such as relay coils, MIO modules, HMI backend circuits, etc.). Through internal filtering and voltage regulation circuits, it ensures that the output voltage ripple is less than [X]mV, meeting the power accuracy requirements of the equipment.

[0038] Wiring and Protection: The AC380V input side is connected to the output circuit of the ER module. After conversion, the DC220V output can be connected to equipment that requires high-voltage DC power supply (if any). The DC24V output is connected to the 24V power supply terminal of the MIO module, the power supply circuit of the relay coil, etc. through wires. A fuse (such as [fuse model, rated current [X]A]) can be added to the circuit as overcurrent protection. When the output current exceeds the rated value, the fuse blows, cutting off the power supply and protecting the electrical equipment.

[0039] The battery pack connection and protection circuit has terminals such as BAT+ and BAT- for connecting the battery pack. The battery pack selection is [specific battery pack model, such as lead-acid battery pack, lithium battery pack, voltage [X]V, capacity [X]Ah]. These terminals work in conjunction with the MIO module and related relays (KA1, KA2, etc.). When the battery pack is connected, the detection circuit determines whether the polarity is correct and the voltage is normal. If the battery polarity is reversed, the MIO module, based on the reverse polarity detection circuit signal, disconnects the battery pack from the main load circuit (e.g., by controlling the relay to disconnect). If the battery voltage is low, the MIO module receives the low voltage detection signal and executes load reduction, alarm, and other protective actions to prevent battery over-discharge damage and ensure the safety of the circuit system and the battery itself.

[0040] Protection Logic Linkage: Deeply integrated with the internal protection program of the MIO module, after the battery pack is connected, the MIO module collects battery voltage and current signals in real time (which can be obtained by connecting [current sensor model, such as Hall current sensor, range [X]A, accuracy [X]%]) and combines them with reverse polarity and low voltage detection signals to comprehensively judge the battery status. When an abnormal state is detected, in addition to cutting off the main circuit and triggering an alarm, the abnormal information can also be transmitted to the HMI display via the communication bus to remind the operator to handle the situation.

[0041] System Bus and Power Supply Network: The 24V and 0V power supply lines in the circuit use [wire specifications, such as RV 1.5mm² copper core wire] to connect DC-consuming devices such as MIO modules, TP1 modules, HMI, and relay coils, constructing a DC power supply network. The 24V line is led out from the DC24V output terminal of the power conversion and output module, and the 0V line is connected to the M terminal of the MIO module and the ground terminal of each module to form a loop. Through reasonable wiring (such as conduit and cable trays), electromagnetic interference is reduced and power supply stability is ensured.

[0042] RS485 Data Bus: Utilizing dedicated RS485 shielded twisted-pair cable, such as RVSP2×1.0mm², it connects the MIO module, TP1 module, and HMI to construct a data transmission bus. Termination resistors (e.g., 120Ω resistors) can be added to both ends of the bus to match the bus impedance, reduce signal reflection, ensure data transmission rate and accuracy, and enable data interaction between modules. This allows for stable transmission of MIO module control commands, battery status data, and HMI interaction commands, supporting coordinated system operation.

[0043] Workflow: Power-on initialization: After the system is connected to AC380V three-phase AC power, the ER module starts working, converting the AC power into power for subsequent circuits. The power conversion and output module completes the AC380V-DC220V-DC24V conversion to power the MIO module, TP1 module, HMI, relays, etc. The MIO module, TP1 module, and HMI complete initialization. The MIO module performs self-tests on its input / output interfaces and internal programs. The TP1 module establishes an RS485 communication link. The HMI loads the initial interface and prepares to receive data.

[0044] Battery Status Monitoring and Protection: After the battery pack is connected, the battery reverse polarity detection circuit operates in real time. KA1 and KA2 relays monitor the battery polarity, and the signal is transmitted to the MIO module. The low voltage disconnection detection line continuously collects the battery voltage and transmits the voltage signal. The MIO module determines whether the battery polarity is normal and whether the voltage is lower than the disconnection threshold according to a preset program.

[0045] If reverse battery polarity is detected, the MIO module outputs a command through the control output terminals such as KO and K1 to disconnect the battery pack from the main load circuit (e.g., to control the main circuit relay to disconnect). At the same time, it sends an alarm signal to the HMI through the TP1 module. The HMI interface displays a "reverse battery polarity" alarm prompt, and an audible and visual alarm (if configured) is activated.

[0046] If a low battery voltage disconnection is detected, the MIO module will also output a control command to prioritize cutting off non-critical loads (such as auxiliary indicator lights and power supply to some backup modules), while preserving power supply to the core detection and protection circuits. At the same time, the HMI will display the "low battery voltage disconnection" status to remind the operator to replace or recharge the battery in time.

[0047] Data Interaction and Human-Machine Collaboration: The MIO module collects data on battery status and its own operating status (such as internal temperature and communication status), and sends it to the TP1 module via the RS485 bus. The TP1 module forwards this data to the HMI, which updates the interface in real time, displaying information such as battery voltage, reverse polarity / low voltage status indicators, and system uptime. Operators can use the HMI buttons / touchscreen to set the battery low voltage disconnection threshold (e.g., adjust it from the default [X]V to [X]V), view historical alarm records (the MIO module can cache [X] historical alarm data entries), calibrate the system time, etc. Operation commands are transmitted back to the MIO module via the TP1 module, executing the corresponding settings and adjustments, thus achieving human-machine collaborative control and monitoring.

[0048] Anomaly Recovery and System Restart: When the battery reverse polarity issue is resolved (correct polarity connection) and the battery low voltage returns to normal (voltage meets standards after charging), the MIO module detects a normal signal again and automatically or manually (according to HMI operation) releases the protection command, restores the connection between the battery pack and the main circuit, and the system gradually resumes normal operation. If the fuse blows or the relay malfunctions due to overcurrent, short circuit, or other faults, after troubleshooting, replace the fuse, reset the relay, and power on again, the system will restart according to the initialization process and resume operation.

[0049] This innovative detection and protection mechanism, utilizing the MIO module to process battery status signals, can quickly respond to reverse polarity or low voltage conditions, cutting off dangerous circuits, adjusting the load, and protecting the battery and circuit system. This reduces the risk of equipment damage and downtime. In field installation, the openable design with clear module connections simplifies operation, eliminating the need for complex wiring and disassembly, avoiding direct connection to high-voltage circuits, reducing impact, and improving installation and maintenance efficiency and safety. Compared to traditional protection circuits, this invention achieves breakthroughs in status monitoring accuracy, system adaptability, and installation convenience, providing a reliable solution for the stable operation of battery-powered systems and promoting the efficient and safe application of related equipment in industrial and other scenarios.

[0050] An external intelligent isolation transmitter for DC power acquisition and measurement, equipped with RS485 communication, works by monitoring the battery's positive and negative voltage polarity in real time. It has two ports connected to the battery's positive and negative terminals. Alternatively, it detects the current flowing through the transmitter's transformer coil to determine if the connection is reversed. This data is then uploaded to the main chip via RS485 communication. The program determines if the polarity is reversed, and the main control board triggers the relay to trip the circuit breaker connected to the battery circuit, providing protection. In addition to the battery's reverse polarity protection, a battery low-voltage disconnect (LVD) function is also designed. When the voltage drops to a set value in the main chip's program, the main control board will also trigger the relay to trip the circuit breaker connected to the battery circuit, providing protection.

[0051] The key technical point of this technical solution is: 1. Employing fully isolated processing technology and using a high-precision 24-bit dedicated AD chip, the dynamic range ratio reaches up to 1000:1. Utilizing Hall effect measurement or resistance sampling measurement principles, it boasts high accuracy, good stability, and high communication speed. The battery reverse polarity protection circuit, composed of the MIO module, battery reverse polarity and low voltage detection circuit, and ER module, possesses significant technical advantages. A control system centered on the MIO module is constructed, receiving and processing battery reverse polarity and low voltage disconnection signals to accurately achieve circuit logic control. In the battery reverse polarity detection circuit, the cooperation between the KA1 and KA2 relays and the MIO module, along with the linkage of the low voltage disconnection detection circuit, enables real-time and accurate monitoring of battery status.

[0052] 2. Measurement of electrical parameters is achieved through remote transmission via RS-485 digital interface. The product's MODBUS protocol is fully compatible with the MODBUS (RTU) protocol in various configuration software or PLC devices. The ER module converts AC to DC to power the system. It works with the power conversion module to adapt to different voltage requirements and ensure the operation of components. The system formed by the modules and the power supply line via the bus realizes reverse polarity detection and protection of the battery and component coordination, effectively avoiding the impact of battery abnormalities on the system, ensuring power supply and system stability, and solving the problems of traditional circuits in accurately monitoring and protecting and adapting to the power supply of multiple components.

[0053] In this embodiment, the entire operation process can be controlled by a computer to provide signal feedback and implement the steps sequentially. These are all conventional knowledge in current automation control, and will not be elaborated on in this embodiment.

[0054] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A battery reverse polarity protection circuit, characterized by, Includes an MIO module, wherein the L1 terminal of the MIO module is connected to a 24V power supply line, and the M terminal is connected to a 0V power supply line; The MIO module is configured with at least two signal input terminals and at least two control output terminals (KO, K1). The signal input terminals are used to receive battery reverse polarity detection signals and low voltage disconnection detection signals, and the control output terminals are used to output protection control commands. The MIO module processes the received signals and generates corresponding control commands through internal logic circuits.

2. A battery reverse polarity protection circuit as defined in claim 1, wherein, The protection circuit also includes a battery reverse polarity detection circuit, in which coils of relays KA1 and KA2 are connected in series. One end of the coil of relay KA1 is connected to the positive terminal of the battery, and the other end is connected to one end of the coil of relay KA2. The other end of the coil of relay KA2 is connected to the first signal input terminal of the MIO module. The normally open contacts of relays KA1 and KA2 are connected in series to the second signal input terminal of the MIO module, forming a reverse polarity signal feedback loop.

3. A battery reverse polarity protection circuit as defined in claim 2, wherein, The protection circuit also includes a battery low voltage disconnection detection circuit, which includes a series voltage divider resistor network and a voltage comparator. The input of the voltage divider resistor network is connected to the output of the battery pack, and the output is connected to the non-inverting input of the voltage comparator. The inverting input of the voltage comparator is connected to a reference voltage source, and the output is connected to the third signal input of the MIO module via an optocoupler.

4. A battery reverse polarity protection circuit as defined in claim 3, wherein, The protection circuit also includes an ER module. The input terminal of the ER module has three phase wire terminals (L1, L2, L3) and one neutral wire terminal (N), which are respectively connected to the three-phase live wire and neutral wire of AC380V, 50Hz, 3P+N AC power. The output terminal of the ER module has a positive terminal and a negative terminal for outputting DC voltage.

5. A battery reverse polarity protection circuit as described in claim 4, characterized in that, The positive terminal of the ER module is connected in series with the PJ1 fuse and then splits into two paths: one path is connected to the input terminal of the power conversion and output module, and the other path is connected to the battery pack charging control circuit; the negative terminal of the ER module is directly connected to the negative input terminal of the power conversion and output module and the negative terminal of the battery pack charging control circuit.

6. A battery reverse polarity protection circuit as described in claim 5, characterized in that, The protection circuit also includes a TP1 module, which has power input terminals (V+, V-) that are connected to a 24V power supply line and a 0V power supply line, respectively. The RS485 interfaces (A, B) of the TP1 module are connected to the RS485 interfaces (A, B) of the MIO module and the RS485 interfaces (A, B) of the HMI, respectively, via shielded twisted-pair cables. The communication baud rate between the TP1 module and the MIO module is set to 9600bps.

7. A battery reverse polarity protection circuit as described in claim 6, characterized in that, The HMI is equipped with power interfaces (24V, 0V) that connect to the 24V power supply line and the 0V power supply line respectively; the RS485 interfaces (A, B) of the HMI are connected to the corresponding RS485 interfaces (A, B) of the TP1 module through shielded twisted pair cables; the HMI and the TP1 module use the Modbus RTU communication protocol for data exchange.

8. A battery reverse polarity protection circuit as described in claim 7, characterized in that, The power conversion and output module includes a QF1-OF conversion unit and a QF1-MX conversion unit. The input terminal of the QF1-OF conversion unit is connected to the output terminal of the ER module after passing through PJ1, and the output terminal (DC220V+, DC220V-) supplies power to the 220V DC load. The input terminal of the QF1-MX conversion unit is connected to the output terminal of the QF1-OF conversion unit, and the output terminal (DC24V+, DC24V-) is connected to the power supply terminals of the MIO module, TP1 module, HMI and relay coil, respectively.

9. A battery reverse polarity protection circuit as described in claim 8, characterized in that, The protection circuit also includes a battery pack connection and protection line, which has a BAT+ terminal and a BAT- terminal, which are respectively connected to the positive and negative terminals of the battery pack; the BAT+ terminal is connected to the positive terminal of the load after being connected in series with the normally closed contact of the KA1 relay; the BAT- terminal is connected to the negative terminal of the load after being connected in series with the normally closed contact of the KA2 relay; the coil control terminals of the KA1 and KA2 relays are respectively connected to the KO and K1 control output terminals of the MIO module.

10. A battery reverse polarity protection circuit as described in claim 9, characterized in that, The 24V and 0V power supply lines use copper core conductors with a cross-sectional area of ​​1.5mm² to form a star grounding network; the metal casings of all modules are connected to the protective grounding terminal (PE) through grounding wires to form grounding protection.

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