UPS battery discharging double-circuit linkage connection protection method

Abstract

The application provides a UPS battery discharge double-path linkage connection protection method in the technical field of power electronics and power distribution safety protection, and comprises the following steps: in response to the access of a first connection port, voltage polarity detection is performed, and if correct, first and second drive signals for driving the first and second thyristors to be turned on are generated, and a first relay node is closed; after a second connection is accessed and polarity is detected to be correct, a signal for allowing conduction is generated, and a second relay node is closed; linkage logic judgment is performed, the first and second drive signals are applied to the control electrodes of the two thyristors through the two relay nodes which are closed in series, the thyristors are switched from bidirectional cut-off to single-phase conduction, and a normal discharge circuit of the battery pack and the UPS system is established. The application has the advantages that the safety and error tolerance capability of the connection operation in the full online discharge test process of the UPS battery are greatly improved, and the risks of short circuit, arc and equipment burning caused by the reverse connection of the double-path voltage polarity are effectively avoided.

Description

Technical Field

[0001] This invention relates to the fields of power electronics technology and power distribution safety protection technology, and in particular to a dual-path linkage wiring protection method for UPS battery discharge. Background Technology

[0002] With the large-scale deployment of information technology infrastructure, data centers have become a key carrier supporting the operation of the digital economy, and the reliability of their power supply systems is directly related to business continuity and data security. In the common power distribution architecture of data centers, high-frequency UPS (Uninterruptible Power Supply) systems and HVDC (High Voltage Direct Current) systems together constitute the core link of end-point power supply. Among them, the UPS system and its supporting battery pack serve as the last line of defense in the event of a mains power outage, making their daily inspection and preventive maintenance particularly critical.

[0003] A typical UPS power system mainly consists of a control unit, charging module, inverter, static switch, and battery bank. Under normal operating conditions, the battery bank is in a long-term float-charge standby state, supplying power to the IT load from the mains power after rectification and inversion. Only when the mains power input is abnormal or interrupted does the battery bank take over the power supply to the load through the discharge circuit. However, because the battery bank is in a static standby state for a long time, the electrochemical performance degradation of its individual cells is difficult to be directly characterized by float-charge parameters, and some cells with hidden degradation or abnormal internal resistance often cannot be detected in time. Once the mains power suddenly fails, these defective cells are very likely to cause the entire battery bank to open circuit or experience a sharp drop in effective capacity, resulting in a power outage of the load, which in turn causes the data center server to crash, triggering a serious operational accident.

[0004] To accurately assess the actual health status of battery banks without interrupting UPS load power supply, existing technologies have developed fully online battery discharge testing methods. These testing schemes allow for continuous load power supply while discharging the battery bank under load. Specifically, high-power freewheeling diodes are typically connected between the positive terminal of the battery bank under test and the positive terminal of the UPS system, as well as between the negative terminal of the battery bank and the negative terminal of the UPS system. This ensures that the battery bank can transiently switch on during mains power fluctuations or brief interruptions, maintaining load power.

[0005] However, such full online test equipment based on freewheeling diodes has prominent safety hazards in the actual engineering wiring stage. Specifically, the test instrument for the backup battery pack supporting the high-frequency UPS host needs to be independently connected to four voltage ports, namely the UPS positive terminal (A1), the battery pack positive terminal (B1), the UPS negative terminal (A2), and the battery pack negative terminal (B2). Due to the coexistence of the four ports, on-site operators face an extremely high risk of incorrect wiring during wiring operations. Theoretical analysis shows that there are a total of 24 different possible combinations for this four-port wiring method, among which as many as 8 combinations will cause serious short-circuit faults due to improper configuration of the diode polarity. For example, when the cable that should be connected to the A1 terminal is mistakenly connected to the negative terminal of the battery pack, an incorrect voltage polarity will be applied across the freewheeling diode, causing the battery pack to form a low-impedance discharge loop through the diode, generating a large instantaneous current, which may not only burn out the diode and the internal PCB circuit, but also cause serious safety accidents such as arcing and fire. Summarizing all error types, their root causes can all be attributed to the reversed voltage polarity input to the corresponding ports of the two freewheeling diodes, that is, as long as any diode is subjected to a reverse voltage across its two ends, the short-circuit risk will be triggered.

[0006] It can thus be seen that the existing full online discharge test equipment lacks an active detection and protection mechanism for the polarity of four-port wiring. Once the polarity is reversely connected, the traditional diode freewheeling scheme cannot independently block or isolate the fault. In the current technical system, no solution that can simultaneously identify the dual-channel voltage polarity states in real time and implement coordinated protection control according to the identification results has been found. Therefore, how to provide a dual-channel coordinated wiring protection method for UPS battery discharge, so as to improve the safety and anti-misoperation and fault tolerance of wiring operations during the full online discharge test of UPS batteries, and effectively avoid the risks of short circuit, arcing and equipment burnout caused by reverse connection of dual-channel voltage polarities, has become an urgent technical problem to be solved. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a dual-channel coordinated wiring protection method for UPS battery discharge, so as to improve the safety and anti-misoperation and fault tolerance of wiring operations during the full online discharge test of UPS batteries, and effectively avoid the risks of short circuit, arcing and equipment burnout caused by reverse connection of dual-channel voltage polarities.

[0008] The present invention provides a dual-channel coordinated wiring protection method for UPS battery discharge, comprising the following steps: Step S1: In response to the connection operation of the first channel wiring port, perform first channel voltage polarity detection; when it is detected that the polarity of the voltage connected to the first channel wiring port is correct, start the driving power module to generate a first driving signal and a second driving signal for driving the first thyristor and the second thyristor to conduct respectively, and simultaneously control the first relay node connected in series on the driving signal transmission path to close. Step S2: In response to the access operation of the second wiring port, perform the second voltage polarity detection; when the voltage polarity of the access to the second wiring port is detected to be correct, generate an enable signal, and control the second relay node connected in series in the drive signal transmission path to close according to the enable signal; Step S3: Perform linkage logic judgment according to the enable signal; when the enable signal is received, the first drive signal and the second drive signal are applied to the control electrode of the first thyristor and the control electrode of the second thyristor respectively after being connected in series through the first relay node and the second relay node; Step S4: In response to the application of the first drive signal and the second drive signal, control the first thyristor and the second thyristor to switch from the bidirectional cutoff state to the single-phase conduction state to establish a normal discharge circuit between the battery pack and the UPS system.

[0009] Furthermore, in step S1, the first wiring port includes the positive terminal of the UPS system and the positive terminal of the battery pack; the correct polarity detection of the first voltage means that both the positive terminal of the UPS system and the positive terminal of the battery pack are connected to positive voltage.

[0010] Furthermore, in step S1, the drive power supply module is a flyback switching power supply with two isolated outputs; when the polarity of the first voltage is detected correctly, the flyback switching power supply starts and outputs two mutually isolated DC drive voltages, which serve as the first drive signal and the second drive signal, respectively.

[0011] Furthermore, in step S1, when the polarity of the first voltage is detected incorrectly, the drive power module cannot start, does not generate the first drive signal and the second drive signal, and the first relay node remains open, the first thyristor and the second thyristor remain in a bidirectional cut-off state, thus blocking the entire discharge circuit.

[0012] Furthermore, in step S2, the second wiring port includes the negative terminal of the UPS system and the negative terminal of the battery pack; the correct polarity detection of the second voltage means that both the negative terminal of the UPS system and the negative terminal of the battery pack are connected to a negative voltage. The second voltage polarity detection is performed by an isolation signal detection circuit, and the enable signal is the node closing signal output by the secondary side of the isolation signal detection circuit; A reverse clamping diode is connected in parallel to the primary input terminal of the isolation signal detection circuit. The reverse clamping diode is used to clamp the voltage input to the primary side of the isolation signal detection circuit to below a safe threshold when a positive voltage is applied to the second terminal, so as to prevent the isolation signal detection circuit from erroneously outputting the enable signal.

[0013] Furthermore, in step S3, the linkage logic judgment is achieved through the first relay node and the second relay node connected in series on the common transmission path of the drive signal; after the first drive signal and the second drive signal are output by the drive power module, they first converge to the input end of the common transmission path of the drive signal, and then, after passing through the first relay node and the second relay node connected in series, they are respectively split from the output end of the common transmission path of the drive signal to the control electrode of the first thyristor and the control electrode of the second thyristor; the first relay node is controlled to close by the first enable signal generated when the polarity of the first voltage is correctly detected, and its excitation power is taken from the first wiring port; the second relay node is directly controlled to close by the enable conduction signal output from the secondary side of the isolation signal detection circuit; the first drive signal and the second drive signal are only synchronously transmitted to the control electrode of the first thyristor and the control electrode of the second thyristor when both the first relay node and the second relay node on the common transmission path of the drive signal are closed.

[0014] Furthermore, in step S3, when the enable signal is not received, the second relay node remains in the off state, the first drive signal and the second drive signal are blocked, and the first thyristor and the second thyristor remain in the bidirectional off state.

[0015] Furthermore, in step S4, the first thyristor is connected between the positive terminal of the UPS system and the positive terminal of the battery pack, and the second thyristor is connected between the negative terminal of the UPS system and the negative terminal of the battery pack; when there is no drive signal, both the first thyristor and the second thyristor are in a bidirectional cutoff state to achieve fault isolation in case of wiring errors.

[0016] Furthermore, in step S1, after the drive power module is started, the first drive signal and the second drive signal are respectively connected to the control electrode of the first thyristor and the control electrode of the second thyristor through a common transmission channel formed by the first relay node and the second relay node connected in series.

[0017] Furthermore, the linkage logic judgment in step S3 is executed by a signal detection and drive linkage control circuit, which includes an isolation detection unit, a relay logic unit, and a thyristor drive unit. The isolation detection unit is used to detect the polarity of the second voltage and output the enable conduction signal, and is electrically isolated from the drive power module. The relay logic unit is used to output a linkage enable signal when the first relay node is closed and the enable conduction signal is received, so as to allow the first drive signal and the second drive signal to be transmitted to the thyristor drive unit. The thyristor drive unit is used to output a trigger current to the first thyristor and the second thyristor after the linkage logic judgment is passed.

[0018] The advantages of this invention are: 1. By starting the drive power supply and closing the first relay node when the first wiring port is connected, and simultaneously performing polarity detection by the isolation signal detection circuit when the second wiring port is connected, and outputting a conduction permission signal to close the second relay node only when the polarity is correct, and connecting these two relay nodes in series on the common transmission path of the drive signal, the first and second drive signals output by the drive power supply can only be synchronously transmitted to the control electrodes of the two thyristors when both polarities are correct and both relay nodes are closed. This controls the thyristors to switch from a bidirectional cutoff state to a single-phase conduction state to establish a normal battery discharge circuit. If either polarity is reversed, the drive power supply cannot start or the relay node remains open, the drive signal is blocked, and the thyristors remain in a bidirectional cutoff state, thus actively blocking the entire discharge circuit. This avoids low-impedance short circuits, high-current arcing, and equipment burnout caused by reverse voltage applied to the freewheeling diode. At the same time, the isolation power supply and reverse clamping diode further enhance the anti-maloperation capability of the detection link, truly realizing fault isolation and linkage protection when wiring errors occur, and significantly improving the safety and fault tolerance of wiring operations during the entire online discharge test.

[0019] 2. By employing independent dual-path voltage polarity detection, the risk of short circuits caused by single-path reverse connection is eliminated at the source. Independent voltage polarity detection is performed on the first connection port (positive side) and the second connection port (negative side). Only when both polarities are detected correctly is the drive power supply allowed to start and a conduction enable signal generated sequentially. This dual-path independent detection mechanism breaks away from the traditional passive protection mode of "defaulting to correct wiring," intercepting the high-risk error of reverse polarity connection before the discharge circuit is established, fundamentally eliminating the accident cause of a low-impedance short circuit circuit formed by the battery pack through diodes due to single-path reverse connection.

[0020] 3. A hard-wired interlocking logic is adopted, where the first and second relay nodes are connected in series along the drive signal transmission path. This ensures that both paths must be correctly connected before conduction, significantly improving fault tolerance and error prevention capabilities. The first and second drive signals must pass through the series-closed first and second relay nodes before being applied to the thyristor's control electrode. This series structure physically implements an AND logic—even if one relay node closes due to misdetection or a fault, the drive signal transmission path is blocked as long as the other path has incorrect polarity or is not connected. This hard-wired interlocking method does not rely on software judgment or complex logic circuits, offering fast response and high reliability. It effectively addresses complex human errors such as incorrect wiring by field operators and mixed cable connections, greatly improving the fault tolerance and error prevention capabilities of the testing equipment during engineering wiring.

[0021] 4. By using thyristors to replace traditional freewheeling diodes and combining them with the linkage control of drive signals, a controllable switching characteristic of "bidirectional cutoff during faults and single-phase conduction during normal operation" is achieved, overcoming the inherent defect of diodes' passive freewheeling inability to isolate faults. The thyristor is in a bidirectional cutoff state when there is no drive signal. Only after both polarities are correct and the drive signal is applied through the series relay node does it switch to a single-phase conduction state to establish a normal discharge circuit. This controllable switching characteristic gives the protection mechanism active isolation capability: when the first polarity detection is incorrect, the drive power module cannot start, the thyristor remains bidirectionally cut off, and the entire discharge circuit is locked; when no allow-to-conduct signal is received, the second relay node opens, similarly blocking the drive signal. Therefore, regardless of whether a reverse connection occurs on the positive or negative side, the thyristor can reliably cut off, completely avoiding safety accidents such as arcing and fire caused by diode reverse breakdown.

[0022] 5. A reverse clamping diode is added for the second polarity detection, effectively preventing the generation of false detection signals and further enhancing the anti-interference robustness of the protection circuit under abnormal wiring conditions. The second voltage polarity detection is performed by the isolation signal detection circuit, whose primary side input terminal is connected in parallel with a reverse clamping diode. When a positive voltage is applied to the second wiring port (i.e., the port that should be negative is mistakenly connected to positive), the clamping diode clamps the input voltage below the safety threshold, preventing the isolation signal detection circuit from erroneously outputting a conduction-allowing signal. This technical detail fully considers the extreme miswiring scenarios that may occur in actual engineering—even if a positive voltage is mistakenly applied to the second port, the detection circuit will not "trick" the relay node into closing, thus ensuring the reliability of the judgment basis of the linkage logic. This clamping design is specifically designed for high-risk scenarios such as the negative terminal being mistakenly connected to the positive terminal, significantly improving the anti-false alarm capability of the detection link and making the protection method more rigorous and comprehensive.

[0023] 6. By activating the drive power module only when the first polarity detection is correct, and using a flyback switching power supply to provide two isolated drive signals, controlled output and electrical isolation of the drive energy are achieved, balancing safety and drive reliability. The drive power module is controlled by the first polarity detection result, activating only when the positive side polarity is correct, and outputting two mutually isolated DC drive voltages. This design has dual advantages: firstly, if the positive side wiring is incorrect, the drive power supply will not work at all, blocking all subsequent actions from the energy supply level and avoiding false triggering; secondly, the two isolated outputs ensure that the control electrode drive signals of the first and second thyristors are independent of each other, preventing interference or parasitic paths caused by common ground issues. Simultaneously, electrical isolation between the isolation detection unit and the drive power module further ensures safe isolation between the low-voltage control circuit and the high-voltage main circuit, meeting the high reliability and low failure rate requirements of data center power distribution systems.

[0024] 7. The linkage logic judgment, relay node series connection, and thyristor drive are integrated into a signal detection and drive linkage control circuit, forming a complete protection closed loop from "polarity detection—logic judgment—drive transmission—thyristor conduction." This circuit has the advantages of clear structure, ease of engineering implementation, and strong scalability. The signal detection and drive linkage control circuit includes an isolation detection unit, a relay logic unit, and a thyristor drive unit. The isolation detection unit completes the second-channel polarity detection and outputs an enable signal. The relay logic unit implements the "AND" logic of the series nodes. The thyristor drive unit outputs a trigger current after the linkage is successful. Compared to the passive solution of simple parallel diodes, this invention systematically solves all risk types of four-port wiring polarity errors (including positive reverse connection, negative reverse connection, and cross-connection of positive and negative terminals) through three levels of protection: active detection, hard-wired interlocking, and controllable switching. This provides a safe, reliable, and easily promoted standardized protection method for UPS battery online discharge testing. Attached Figure Description

[0025] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0026] Figure 1 This is a flowchart of a dual-circuit linkage wiring protection method for UPS battery discharge according to the present invention.

[0027] Figure 2 This is a circuit diagram of the signal detection and drive linkage control circuit of the present invention.

[0028] Figure 3 This is a circuit diagram of the signal detection and drive linkage control circuit of the present invention. Detailed Implementation

[0029] The overall concept of the technical solution in this application embodiment is as follows: By independently detecting the voltage polarity of the first (positive side) and second (negative side) wiring ports, the drive power module is started and the first relay node is closed only when the polarity of the positive side is correct. At the same time, when the polarity of the negative side is correct, the isolation signal detection circuit outputs an enable signal and closes the second relay node. These two relay nodes are connected in series on the common transmission path of the drive signal, so that the two drive signals output by the drive power supply can only be synchronously applied to the control electrodes of the first and second thyristors when both nodes on the series path are closed, thereby controlling the thyristor to switch from bidirectional cutoff to single-phase conduction to establish a normal discharge circuit. If either polarity is reversed or not connected, the drive power supply cannot start or the second relay node remains open, the drive signal is blocked, and the thyristor maintains a bidirectional cutoff state, realizing active blocking and fault isolation of the discharge circuit. Thus, through the three-level protection of "dual-path independent detection - hard-wired series interlocking - controllable switch conduction", the risk of short circuit, arcing and equipment burnout caused by incorrect polarity of the four-port wiring is systematically solved.

[0030] Please refer to Figures 1 to 3 As shown, a preferred embodiment of the UPS battery discharge dual-circuit linkage wiring protection method of the present invention includes the following steps: Step S1: In response to the access operation of the first wiring port, perform the first voltage polarity detection; when the voltage polarity of the access to the first wiring port is detected to be correct, start the drive power module to generate the first drive signal and the second drive signal for driving the first thyristor and the second thyristor to conduct respectively, and at the same time control the first relay node connected in series in the drive signal transmission path to close. In a preferred implementation of the first voltage polarity detection, the first voltage polarity detection is performed by a positive polarity detection circuit, which includes a first optocoupler and a second optocoupler. The anode of the primary side of the first optocoupler is connected to the positive terminal (A1) of the UPS system via a first current-limiting resistor, and the cathode of the primary side is connected to the positive terminal (B1) of the battery pack. The anode of the primary side of the second optocoupler is connected to the positive terminal (B1) of the battery pack via a second current-limiting resistor, and the cathode of the primary side is connected to the positive terminal (A1) of the UPS system. After the secondary sides of the first optocoupler and the second optocoupler are connected in series, the first enable signal is output. When both A1 and B1 are connected to a positive voltage and the voltage difference between A1 and B1 is greater than the conduction threshold of the first and second optocouplers, the first and second optocouplers conduct simultaneously, and the secondary side outputs a valid first enable signal to start the drive power module and control the closing of the first relay node. When either A1 or B1 is not connected to a positive voltage, or the voltage difference between A1 and B1 is insufficient, at least one of the first and second optocouplers is cut off and does not output the first enable signal. By using two optocouplers connected in series to detect that A1 and B1 are mutually positive voltages, it is possible to reliably determine whether both wires of the first wiring port are correctly connected to a positive voltage, effectively avoiding false detections caused by single-wire connection or reverse connection.

[0031] Step S2: In response to the access operation of the second wiring port, perform the second voltage polarity detection; when the voltage polarity of the access to the second wiring port is detected to be correct, generate an enable signal, and control the second relay node connected in series in the drive signal transmission path to close according to the enable signal; Step S3: Perform linkage logic judgment according to the enable signal; when the enable signal is received, the first drive signal and the second drive signal are applied to the control electrode of the first thyristor and the control electrode of the second thyristor respectively after being connected in series through the first relay node and the second relay node; Step S4: In response to the application of the first drive signal and the second drive signal, control the first thyristor and the second thyristor to switch from the bidirectional cutoff state to the single-phase conduction state to establish a normal discharge circuit between the battery pack and the UPS system.

[0032] In step S1, the first connection port includes the positive terminal of the UPS system and the positive terminal of the battery pack; the correct voltage polarity detection of the first line means that both the positive terminal of the UPS system and the positive terminal of the battery pack are connected to positive voltage.

[0033] In step S1, the drive power supply module is a flyback switching power supply with two isolated outputs; when the polarity of the first voltage is detected correctly, the flyback switching power supply starts and outputs two mutually isolated DC drive voltages, which serve as the first drive signal and the second drive signal, respectively.

[0034] In step S1, when the polarity of the first voltage is detected incorrectly, the drive power module cannot start, does not generate the first drive signal and the second drive signal, and the first relay node remains open, the first thyristor and the second thyristor remain in a bidirectional cut-off state, thus blocking the entire discharge circuit.

[0035] In step S2, the second wiring port includes the negative terminal of the UPS system and the negative terminal of the battery pack; the second voltage polarity detection is correct, which means that both the negative terminal of the UPS system and the negative terminal of the battery pack are connected to a negative polarity voltage; The second voltage polarity detection is performed by an isolation signal detection circuit, and the enable signal is the node closing signal output by the secondary side of the isolation signal detection circuit; A reverse clamping diode is connected in parallel to the primary input terminal of the isolation signal detection circuit. The reverse clamping diode is used to clamp the voltage input to the primary side of the isolation signal detection circuit to below a safe threshold when a positive voltage is applied to the second terminal, so as to prevent the isolation signal detection circuit from erroneously outputting the enable signal.

[0036] As a preferred implementation of the isolation signal detection circuit, the isolation signal detection circuit adopts an optocoupler-isolated voltage polarity detection circuit, which includes a third optocoupler, a fourth optocoupler, and the reverse clamping diode. The anode of the primary side of the third optocoupler is connected to the negative terminal (A2) of the UPS system via a third current-limiting resistor, and the cathode of the primary side is connected to the negative terminal (B2) of the battery pack; the anode of the primary side of the fourth optocoupler is connected to the negative terminal (B2) of the battery pack via a fourth current-limiting resistor, and the cathode of the primary side is connected to the negative terminal (A2) of the UPS system. The secondary sides of the third and fourth optocouplers are connected in series. When both A2 and B2 are connected to a negative polarity voltage and the voltage difference between A2 and B2 is greater than the conduction threshold of the third and fourth optocouplers, the third and fourth optocouplers are simultaneously turned on, and their secondary sides output the enable signal. The reverse clamping diode is connected in parallel between the anode and cathode of the primary side of the third optocoupler. Its anode is connected to the cathode of the primary side of the third optocoupler, and its cathode is connected to the anode of the primary side of the third optocoupler. This reverse clamping diode is used to clamp the forward voltage drop of the primary side of the third optocoupler to no more than 0.7V when A2 or B2 is mistakenly connected to a positive voltage, so that the third optocoupler cannot conduct, thereby preventing the isolation signal detection circuit from erroneously outputting the enable signal. Preferably, the reverse clamping diode is a Schottky diode with a forward voltage drop of no more than 0.4V to further reduce the clamping voltage and improve the reliability of preventing malfunction. The safety threshold is determined according to the conduction threshold of the selected optocoupler, and is usually set to no more than the forward voltage drop of the light-emitting diode on the primary side of the selected optocoupler (typically 1.0V~1.5V) to ensure that the optocoupler is reliably cut off when a positive voltage is mistakenly connected.

[0037] In step S3, the linkage logic judgment is achieved by connecting the first relay node and the second relay node in series on the common transmission path of the drive signal. After the first drive signal and the second drive signal are output by the drive power module, they are first gathered at the input end of the common transmission path of the drive signal, and then, after passing through the first relay node and the second relay node in series, they are respectively split from the output end of the common transmission path of the drive signal to the control electrode of the first thyristor and the control electrode of the second thyristor. The first relay node is controlled to close by the first enable signal generated when the polarity of the first voltage is correctly detected, and its excitation power is taken from the first wiring port. The second relay node is directly controlled to close by the enable signal output by the secondary of the isolation signal detection circuit. The first drive signal and the second drive signal are only synchronously transmitted to the control electrode of the first thyristor and the control electrode of the second thyristor when both the first relay node and the second relay node on the common transmission path of the drive signal are closed.

[0038] The linkage logic judgment is not an additional judgment step independent of the closing of node K2, but a hardware logic judgment implemented through the series topology of relay nodes at the physical level. Specifically, when the isolation signal detection circuit detects that the polarity of the second wiring is correct, it outputs the enable signal, which directly drives the excitation coil of the second relay K2, causing node K2.b to close. The phrase "execute linkage logic judgment according to the enable signal" means that when the enable signal has been generated and drives K2.b to close, both the first relay node K1.b and the second relay node K2.b on the common transmission path of the drive signal are in a closed state, and the drive signal can be transmitted to the thyristor control electrode through this series path; when the enable signal has not been generated, K2.b remains open, and the drive signal is blocked—the on / off state of this path itself is the result of the linkage logic judgment. Therefore, the core meaning of the linkage logic judgment is that the on / off state of the two relay nodes connected in series jointly determines whether the drive signal can be transmitted. The first relay node represents "the first polarity detection is correct", and the second relay node represents "the second polarity detection is correct (i.e., the enable signal has been generated)". Both conditions are indispensable. This physical-level hardware "AND" logic judgment does not require additional software or logic circuits, and has a fast response speed and high reliability. The phrase "when the enable signal is received" in step S3 should be understood as "when the enable signal has successfully driven the second relay node to close", rather than the enable signal being an additional software judgment condition.

[0039] In step S3, when the enable signal is not received, the second relay node remains in the off state, the first drive signal and the second drive signal are blocked, and the first thyristor and the second thyristor remain in the bidirectional cut-off state.

[0040] In step S4, the first thyristor is connected between the positive terminal of the UPS system and the positive terminal of the battery pack, and the second thyristor is connected between the negative terminal of the UPS system and the negative terminal of the battery pack. When there is no drive signal, both the first thyristor and the second thyristor are in a bidirectional cut-off state to achieve fault isolation in case of wiring errors.

[0041] The anode of the first thyristor (SCR1) is connected to the positive terminal (B1) of the battery pack, and the cathode is connected to the positive terminal (A1) of the UPS system. Its conduction direction is unidirectional, from the positive terminal (B1) of the battery pack to the positive terminal (A1) of the UPS system, to achieve a forward path for the battery pack discharge current. The anode of the second thyristor (SCR2) is connected to the negative terminal (A2) of the UPS system, and the cathode is connected to the negative terminal (B2) of the battery pack. Its conduction direction is unidirectional, from the negative terminal (A2) of the UPS system to the negative terminal (B2) of the battery pack, to achieve a return path for the battery pack discharge current. When SCR1 and SCR2 are both turned on, the path of the battery pack discharge current is: positive terminal (B1) of the battery pack → SCR1 → positive terminal (A1) of the UPS system → UPS system load → negative terminal (A2) of the UPS system → SCR2 → negative terminal (B2) of the battery pack, forming a complete discharge circuit. The direction of conduction is set in accordance with the discharge current flow direction of the battery pack during the full online discharge test, ensuring that the discharge circuit from the battery pack to the UPS system can be established normally when both polarity detections are correct and the linkage logic passes.

[0042] In step S1, after the drive power module is started, the first drive signal and the second drive signal are respectively connected to the control electrode of the first thyristor and the control electrode of the second thyristor through a common transmission channel formed by the first relay node and the second relay node connected in series.

[0043] The linkage logic judgment in step S3 is executed by a signal detection and drive linkage control circuit, which includes an isolation detection unit, a relay logic unit, and a thyristor drive unit. The isolation detection unit is used to detect the polarity of the second voltage and output the enable conduction signal, and is electrically isolated from the drive power module. The relay logic unit is used to output a linkage enable signal when the first relay node is closed and the enable conduction signal is received, so as to allow the first drive signal and the second drive signal to be transmitted to the thyristor drive unit. The thyristor drive unit is used to output a trigger current to the first thyristor and the second thyristor after the linkage logic judgment is passed.

[0044] To achieve the linkage protection function described in steps S1-S4 above, this embodiment provides a signal detection and drive linkage control circuit as a preferred implementation. Please refer to... Figure 2 As shown, the circuit mainly includes a drive power supply module, an isolation signal detection circuit, a first relay K1, a second relay K2, a first thyristor SCR1, and a second thyristor SCR2.

[0045] The drive power module adopts a flyback switching power supply topology. Its input terminal is connected to the first wiring port (i.e., the positive terminal A1 of the UPS system and the positive terminal B1 of the battery pack), and an anti-reverse diode D2 is connected in series at the input terminal. The drive power module has two electrically isolated output windings, which are used to output the first drive signal DC1+ and the second drive signal DC2+, respectively. When the voltage polarity of the first wiring port is correct (i.e., both A1 and B1 are connected to positive voltage), the drive power module starts automatically and outputs two mutually isolated 12V / 0.5A DC drive voltages. When the voltage polarity of the first wiring port is incorrect (including reverse connection or no connection), due to the blocking effect of the anti-reverse diode D2, the drive power module cannot obtain the normal operating voltage, thus it cannot start and does not generate the first drive signal and the second drive signal.

[0046] The excitation coil of the first relay K1 is connected to the first wiring port, and its node K1.b is a set of normally open nodes connected in series in the common transmission path of the drive signal. When the polarity of the first wiring is correct, the first relay K1 is energized and its normally open node K1.b closes.

[0047] The input terminal of the isolation signal detection circuit is connected to the second wiring port (i.e., the negative terminal A2 of the UPS system and the negative terminal B2 of the battery pack) to perform the second voltage polarity detection, and an anti-reverse diode D1 is connected in series at the input terminal. A reverse clamping diode (not shown) is also connected in parallel at the primary input terminal of the isolation signal detection circuit. When the second wiring port is mistakenly connected to a positive voltage, this reverse clamping diode clamps the voltage input to the primary side of the isolation signal detection circuit below a safe threshold (e.g., below 0.7V), preventing the isolation signal detection circuit from malfunctioning due to overvoltage. The secondary output terminal of the isolation signal detection circuit is connected to the excitation coil of the second relay K2. Node K2.b of the second relay K2 is a set of normally open nodes, also connected in series on the common transmission path of the drive signal, and forms a series relationship with node K1.b of the first relay. The isolation signal detection circuit outputs a conduction enable signal (i.e., node closure signal) only when the polarity of the second wiring is correct (i.e., both A2 and B2 are connected to negative voltage), which energizes the second relay K2 and closes its normally open node K2.b.

[0048] The first thyristor SCR1 is connected between the positive terminal A1 of the UPS system and the positive terminal B1 of the battery pack, and the second thyristor SCR2 is connected between the negative terminal A2 of the UPS system and the negative terminal B2 of the battery pack. The control terminals of SCR1 and SCR2 are respectively connected to the output terminals of the common transmission path of the drive signal. When no drive signal is received, both SCR1 and SCR2 are in a bidirectional cutoff state; when the control terminal receives a trigger current, SCR1 and SCR2 switch to a single-phase conduction state, establishing conduction paths A1→B1 and B2→A2 respectively.

[0049] It should be further explained that the first drive signal DC1+ and the second drive signal DC2+ are provided by two isolated output windings of the drive power module, and are electrically isolated from each other. After being output from the drive power module, DC1+ and DC2+ are respectively connected to the input terminal node of the common transmission path of the drive signals. On the common transmission path, DC1+ and DC2+ are each connected to the control electrode of SCR1 and the control electrode of SCR2 after passing through K1.b and K2.b in series. Specifically, DC1+ is applied between the control electrode and cathode of SCR1 after passing through the series link of K1.b and K2.b, providing the gate current required for the thyristor to be triggered and turned on; DC2+ is applied between the control electrode and cathode of SCR2 after passing through the same series link. Since the two drive signals share the common transmission channel formed by the series connection of K1.b and K2.b, when either relay node is disconnected, DC1+ and DC2+ are simultaneously blocked, realizing the synchronous linkage control of the two thyristors.

[0050] The drive voltage parameters output by the drive power supply module can be adjusted according to the gate triggering characteristics of the selected thyristor. In this embodiment, the drive power supply module adopts a flyback switching power supply topology, and its output is two 12V / 0.5A isolated DC power supplies, which is sufficient to meet the gate triggering current requirements of most large thyristors (e.g., rated current of 100A and above). At the same time, the 0.5A current-limiting output also takes into account the protection of the control electrode. In specific implementations, those skilled in the art can adaptively adjust the output voltage and current parameters of the flyback switching power supply according to the actual selected thyristor model (e.g., using 15V / 0.3A or 24V / 0.2A, etc.), which falls within the scope of equivalent transformations of this invention.

[0051] Furthermore, electrical isolation is achieved between the isolation signal detection circuit and the drive power module, as well as between the first wiring port and the second wiring port, ensuring that there is no electrical coupling between the low-voltage control circuit and the high-voltage main circuit. This not only protects the personal safety of the operators but also avoids electromagnetic interference or parasitic conduction paths introduced by common grounding issues.

[0052] Based on the above circuit structure, the working principle of the linkage protection of the present invention will be further explained below in conjunction with two typical wiring scenarios.

[0053] Scenario 1: Incorrect wiring at the first connection port (A1 / B1). When the operator connects the test cable to the A1 / B1 port, if the polarity of A1 and B1 is reversed (for example, a cable that should be connected to A1 is mistakenly connected to B1, a cable that should be connected to B1 is mistakenly connected to A1, or either A1 or B1 is actually connected to a negative voltage), due to the unidirectional conductivity of the anti-reverse diode D2, a normal operating voltage cannot be established between the positive and negative terminals of the drive power module's input. The drive power module cannot start and does not generate the DC1+ and DC2+ drive signals. At the same time, the first relay K1 cannot be energized due to the incorrect voltage polarity at its excitation coil terminals, and its normally open terminal K1.b remains open. At this time, regardless of whether the second connection port (A2 / B2) is wired correctly, the common transmission path of the drive signal is cut off by K1.b. There is no trigger current at the control terminals of the first thyristor SCR1 and the second thyristor SCR2, and SCR1 and SCR2 remain in a bidirectional cut-off state, completely blocking the entire discharge circuit. This avoids the battery pack forming a low-impedance short-circuit discharge circuit through the freewheeling device due to reverse polarity of the first circuit, thus completely eliminating the risks of short circuits, arcing, and equipment burnout.

[0054] Scenario 2: The first wiring port (A1 / B1) is correctly wired, but the second wiring port (A2 / B2) is incorrectly wired. When the polarity of A1 / B1 is correct, the drive power module starts normally and outputs two 12V isolated drive signals, DC1+ and DC2+; simultaneously, the first relay K1 is energized, and its normally open terminal K1.b closes. At this time, if the second wiring port A2 / B2 is incorrectly wired (e.g., a cable that should be connected to A2 is mistakenly connected to B2, a cable that should be connected to B2 is mistakenly connected to A2, or either A2 / B2 is actually connected to a positive voltage), the isolation signal detection circuit detects an abnormal voltage polarity, and its secondary side does not output a conduction permission signal; if A2 / B2 is mistakenly connected to a positive voltage, the reverse clamping diode clamps the input voltage below a safe threshold, further ensuring that the isolation signal detection circuit does not malfunction. Since no conduction permission signal is received, the second relay K2 is not energized, and its normally open terminal K2.b remains open. Although K1.b is closed, K1.b and K2.b are connected in series on the common transmission path of the drive signal. The disconnection of K2.b makes the entire transmission path still open. The DC1+ and DC2+ drive signals cannot be applied to the control electrodes of SCR1 and SCR2. SCR1 and SCR2 remain in a bidirectional cut-off state, and the discharge circuit is locked.

[0055] In summary, the drive power module only starts outputting DC1+ and DC2+ when the voltage polarity of the first connection port (A1 / B1) and the second connection port (A2 / B2) is correctly detected, i.e., when A1 and B1 are both connected to positive voltage and A2 and B2 are both connected to negative voltage. K1.b and K2.b are both closed. DC1+ and DC2+ are then applied to the control terminals of SCR1 and SCR2 respectively through a common transmission channel formed by the series-connected K1.b and K2.b. SCR1 and SCR2 synchronously switch to single-phase conduction state, establishing a normal discharge circuit between the battery pack and the UPS system. The topology of the two relay nodes connected in series physically ensures that if any node in the logic-drive signal transmission path is disconnected, the entire path is blocked, and the thyristor cannot conduct.

[0056] While specific embodiments of the present invention have been described above, those skilled in the art should understand that the specific embodiments described are merely illustrative and not intended to limit the scope of the present invention. Equivalent modifications and variations made by those skilled in the art in accordance with the spirit of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for dual-circuit linkage wiring protection of UPS battery discharge, characterized in that, Includes the following steps: Step S1: In response to the access operation of the first wiring port, perform the first voltage polarity detection; when the voltage polarity of the access to the first wiring port is detected to be correct, start the drive power module to generate the first drive signal and the second drive signal for driving the first thyristor and the second thyristor to conduct respectively, and at the same time control the first relay node connected in series in the drive signal transmission path to close. Step S2: In response to the access operation of the second wiring port, perform the second voltage polarity detection; when the voltage polarity of the access to the second wiring port is detected to be correct, generate an enable signal, and control the second relay node connected in series in the drive signal transmission path to close according to the enable signal; Step S3: Perform linkage logic judgment according to the enable signal; when the enable signal is received, the first drive signal and the second drive signal are applied to the control electrode of the first thyristor and the control electrode of the second thyristor respectively after being connected in series through the first relay node and the second relay node; Step S4: In response to the application of the first drive signal and the second drive signal, control the first thyristor and the second thyristor to switch from the bidirectional cutoff state to the single-phase conduction state to establish a normal discharge circuit between the battery pack and the UPS system.

2. The method for dual-circuit linkage wiring protection of UPS battery discharge according to claim 1, characterized in that, In step S1, the first connection port includes the positive terminal of the UPS system and the positive terminal of the battery pack; the correct voltage polarity detection of the first line means that both the positive terminal of the UPS system and the positive terminal of the battery pack are connected to positive voltage.

3. The UPS battery discharge dual-circuit linkage wiring protection method according to claim 1, characterized in that, In step S1, the drive power supply module is a flyback switching power supply with two isolated outputs; when the polarity of the first voltage is detected correctly, the flyback switching power supply starts and outputs two mutually isolated DC drive voltages, which serve as the first drive signal and the second drive signal, respectively.

4. The UPS battery discharge dual-circuit linkage wiring protection method according to claim 1, characterized in that, In step S1, when the polarity of the first voltage is detected incorrectly, the drive power module cannot start, does not generate the first drive signal and the second drive signal, and the first relay node remains open, the first thyristor and the second thyristor remain in a bidirectional cut-off state, thus blocking the entire discharge circuit.

5. The UPS battery discharge dual-circuit linkage wiring protection method according to claim 1, characterized in that, In step S2, the second wiring port includes the negative terminal of the UPS system and the negative terminal of the battery pack; the second voltage polarity detection is correct, which means that both the negative terminal of the UPS system and the negative terminal of the battery pack are connected to a negative polarity voltage; The second voltage polarity detection is performed by an isolation signal detection circuit, and the enable signal is the node closing signal output by the secondary side of the isolation signal detection circuit; A reverse clamping diode is connected in parallel to the primary input terminal of the isolation signal detection circuit. The reverse clamping diode is used to clamp the voltage input to the primary side of the isolation signal detection circuit to below a safe threshold when a positive voltage is applied to the second terminal, so as to prevent the isolation signal detection circuit from erroneously outputting the enable signal.

6. The method for dual-circuit linkage wiring protection of UPS battery discharge according to claim 1, characterized in that, In step S3, the linkage logic judgment is achieved by connecting the first relay node and the second relay node in series on the common transmission path of the drive signal. After the first drive signal and the second drive signal are output by the drive power module, they are first gathered at the input end of the common transmission path of the drive signal, and then, after passing through the first relay node and the second relay node in series, they are respectively split from the output end of the common transmission path of the drive signal to the control electrode of the first thyristor and the control electrode of the second thyristor. The first relay node is controlled to close by the first enable signal generated when the polarity of the first voltage is correctly detected, and its excitation power is taken from the first wiring port. The second relay node is directly controlled to close by the enable signal output by the secondary of the isolation signal detection circuit. The first drive signal and the second drive signal are only synchronously transmitted to the control electrode of the first thyristor and the control electrode of the second thyristor when both the first relay node and the second relay node on the common transmission path of the drive signal are closed.

7. The method for dual-circuit linkage wiring protection of UPS battery discharge according to claim 1, characterized in that, In step S3, when the enable signal is not received, the second relay node remains in the off state, the first drive signal and the second drive signal are blocked, and the first thyristor and the second thyristor remain in the bidirectional cut-off state.

8. A method for dual-circuit linkage wiring protection of UPS battery discharge according to claim 1, characterized in that, In step S4, the first thyristor is connected between the positive terminal of the UPS system and the positive terminal of the battery pack, and the second thyristor is connected between the negative terminal of the UPS system and the negative terminal of the battery pack. When there is no drive signal, both the first thyristor and the second thyristor are in a bidirectional cut-off state to achieve fault isolation in case of wiring errors.

9. A method for dual-circuit linkage wiring protection of UPS battery discharge according to any one of claims 1 to 8, characterized in that, In step S1, after the drive power module is started, the first drive signal and the second drive signal are respectively connected to the control electrode of the first thyristor and the control electrode of the second thyristor through a common transmission channel formed by the first relay node and the second relay node connected in series.

10. A method for dual-circuit linkage wiring protection of UPS battery discharge according to any one of claims 1 to 8, characterized in that, The linkage logic judgment in step S3 is executed by a signal detection and drive linkage control circuit, which includes an isolation detection unit, a relay logic unit, and a thyristor drive unit. The isolation detection unit is used to detect the polarity of the second voltage and output the enable conduction signal, and is electrically isolated from the drive power module. The relay logic unit is used to output a linkage enable signal when the first relay node is closed and the enable conduction signal is received, so as to allow the first drive signal and the second drive signal to be transmitted to the thyristor drive unit. The thyristor driving unit is used to output trigger current to the first thyristor and the second thyristor after the linkage logic judgment is passed.

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