Remote capacity checking and failure battery non-power-cut replacement device for direct-current storage battery pack of transformer substation

Abstract

The invention relates to a remote capacity checking and failure battery non-power-off replacement device for a direct-current storage battery pack of a transformer substation, which comprises a junction box, a controller U1 and a remote capacity checking system, and is characterized in that a group of test loops, a group of main through loops, two parallel multi-head quick binding posts and a display loop are arranged in the junction box; the input end of the controller U1 is connected with a reference voltage unit for providing reference voltage for the controller U1 and a measuring unit for measuring the voltage of the storage battery, and the input end of the measuring unit is connected with a battery short-circuit unit; the remote capacity checking system comprises a capacity checking management platform, a battery management module, a capacity checking module and a plurality of remote discharge control boxes, the battery management module is respectively connected with the capacity checking module, the capacity checking management platform and the plurality of remote discharge control boxes, and the capacity checking module is connected with the storage battery pack; the method has the advantages that the method is suitable for a single-group or multi-group parallel system, power failure is avoided through remote capacity checking, the wiring polarity can be judged, and the working efficiency is improved.

Description

Technical Field

[0001] This invention belongs to the field of substation technology, specifically relating to a device for remote capacity verification of DC battery banks in substations and uninterrupted power replacement of failed batteries. Background Technology

[0002] As the last line of defense providing power to the entire DC power system of a substation, the importance of battery banks in the DC system is self-evident. When the AC system experiences a power outage due to a fault, the normal operation of the battery banks ensures the continued operation of the communication system. Inadequate battery operation and maintenance can pose potential risks to the safe and stable operation of the power grid. Traditional system maintenance mainly relies on manual, periodic inspections of the backup battery status of the DC system at each substation, focusing on verifying battery capacity. This capacity verification is generally time-consuming, resulting in a significant waste of manpower. Furthermore, with the continuous increase in the number of substations and batteries, the number of maintenance personnel has not increased accordingly, making it difficult to achieve optimal performance for each battery bank. Maintenance is crucial because equipment risks shutdown in the event of AC system power outages. Furthermore, power outages caused by substations occupying power sources can easily lead to grid accidents. To ensure the safe and stable operation of the power grid, it is necessary to replace individual or multiple faulty batteries, or the entire battery bank. Commonly used battery junction boxes have the following problems: ① Before connecting the battery, the positive and negative terminals of the junction box (containing diodes) must be clearly identified, and the polarity of the battery to be replaced must be manually determined before connection. Incorrect connection can cause a short circuit (short-circuit DC current is 200-400A, while the AC current of a typical welding machine is around 120-200A). Additionally, the low spacing between battery cells makes it easy for the DC system to ground. ① It can cause severe fluctuations in DC system voltage, leading to substation equipment burnout or protection tripping; ② After connection, the connection status cannot be reflected in real time. One person needs to use DC clamps to continuously clamp the circuit and monitor the circuit power supply; ③ When replacing the entire battery pack, during the process of connecting the temporary battery pack, because the battery fuse is located below the cabinet and very close to the cabinet body, and the fuse terminals are wide, the temporary battery clamps cannot be clamped and connected in one go. It is necessary to repeatedly change the direction of clamping to find the most stable position. The repeated contact between the two battery packs due to the voltage difference can cause arcing and DC system voltage fluctuations, which can affect and damage the DC system control unit and measurement and control components; ④ Because the capacity meter wiring is divided into current and voltage clamps, a total of Four clips are used, but there is often not enough space below the fuse to clamp all four clips simultaneously during capacity verification, which affects the disconnection of the battery pack; ⑤ The positive and negative terminals of the junction box cannot be removed when not in use, which is inconvenient for handling and storage. The exposed wires are easily crushed and scattered during handling, causing electric shock and equipment risks; Currently, replacing failed batteries generally involves disconnecting the DC power supply, connecting the spare battery to the charger, and then removing the battery to be replaced. This greatly reduces the replacement speed and affects the safety of DC system operation; Therefore, it is very necessary to provide a remote capacity verification and uninterrupted replacement device for DC battery packs in substations that is suitable for single or multiple parallel systems, allows for remote capacity verification to avoid power outages, can determine wiring polarity, and improves work efficiency. Summary of the Invention

[0003] (I) Technical Solution

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a device for remote capacity assessment and uninterrupted replacement of failed batteries for DC battery banks in substations, applicable to single or multiple parallel systems, enabling remote capacity assessment to avoid power outages, determining wiring polarity, and improving work efficiency.

[0005] The objective of this invention is achieved as follows: a remote capacity verification and uninterrupted power-off battery replacement device for DC battery banks in substations, comprising a junction box, a controller U1, and a remote capacity verification system. Both the junction box and the remote capacity verification system are connected to the controller U1. The junction box contains a test circuit, a main circuit, two parallel multi-head quick-connect terminals, and a display circuit. An audible and visual alarm is connected in series with the test circuit. The display circuit is connected to a display screen. The controller U1's input terminal is connected to a reference voltage unit that provides a reference voltage to the controller U1 and a measuring unit for measuring battery voltage. A battery short-circuit unit is connected to the input terminal of the measuring unit. The battery short-circuit unit is connected to the controller U1 using an optocoupler-isolated drive circuit. The remote capacity verification system includes a capacity management platform, a battery management module, a capacity verification module, and a remote discharge control box. The battery management module is connected to the capacity verification module, the capacity management platform, and multiple remote discharge control boxes. The capacity verification module is connected to the battery bank.

[0006] Specifically, this invention is a wiring device that can determine wiring polarity, has audible and visual alarms, displays current and voltage, and is equipped with multiple quick-connect terminals. By displaying the current in real time, this invention achieves efficient workload reduction, improves work efficiency, reduces the operational risks of substation automation and protection equipment during DC system battery maintenance, and ensures the safe and stable operation of the power grid, thus having promotional value.

[0007] Furthermore, the anti-misoperation unit includes diodes VD2 and VD3, and an optocoupler isolation module U2; the VCC terminal of the optocoupler isolation module U2 is connected to the power supply terminal Vcc, the GND terminal is grounded, the A terminal is connected to the power supply terminal Vcc via resistor R2, the K terminal is connected to the P1.5 terminal of the controller U1, and the VO terminal is connected to the control electrode of the thyristor VS via resistor R9; the negative terminal of diode VD2 is connected to the control electrode of the thyristor VS, and the positive terminal is connected to the positive terminal of diode VD3; the negative terminal of diode VD3 is connected to the cathode of the thyristor VS, and the negative terminal is grounded; the cathode of the thyristor VS is connected to the negative terminal of the battery, and the anode is connected to the positive terminal of the battery.

[0008] Furthermore, the power supply unit includes a DC-DC power converter U3 and a fuse F1; the Vin- terminal of the DC-DC power converter U3 is connected to the negative terminal of the lithium battery, the Vin+ terminal is connected to the positive terminal of the lithium battery via the fuse F1, a polarized capacitor C1 and a capacitor C2 are provided between the Vin- terminal and the Vin+ terminal, and a polarized capacitor C3 and a capacitor C5 are provided between the COM terminal and the Vo+ terminal; the positive terminal of the polarized capacitor C3 is connected to the power supply terminal Vcc, and the negative terminal is grounded.

[0009] Furthermore, the remote discharge control box of the remote capacity system includes diode D1, diode D2, switch K, fault diagnosis module, and current input / output terminal. The fault diagnosis module is connected to the power supply terminal and the communication terminal respectively, and the fault diagnosis module is connected in parallel with diode D1, diode D2 and switch K in sequence and then connected to the current input / output terminal.

[0010] (II) Beneficial Effects

[0011] 1. This invention can determine the polarity of the wiring, has an audible and visual alarm, and also displays current and voltage. The junction box is equipped with multiple quick-connect terminals, which facilitates on-site testing and improves on-site work efficiency.

[0012] 2. Simple battery wiring and operating status monitoring function: The junction box is equipped with a test circuit, a main circuit, two parallel multi-head quick terminals and a display circuit; the display circuit is connected to the display screen, which displays the current parameters passing through the main circuit and monitors in real time whether the online battery pack is interrupted.

[0013] 3. This invention employs a DC contactor and multiple diode structure design for the core capacitor technology, enabling it to have remote discharge control and self-test functions, while also designing multiple operating modes to provide protection capabilities;

[0014] 4. The remote capacity verification system of the present invention is applicable not only to a single battery bank, but also to a system in which multiple battery banks are connected in parallel, ensuring that when the battery bank is remotely verified by disconnecting from the DC bus, there is no risk of power outage due to AC power failure. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0016] Figure 2 This is the electrical wiring diagram of the junction box of the present invention.

[0017] Figure 3 This is a circuit diagram of the power supply unit of the present invention.

[0018] Figure 4 This is a schematic diagram of the voltage digital-to-analog conversion principle of the present invention.

[0019] Figure 5 This is a schematic diagram of the voltage sampling circuit of the present invention.

[0020] Figure 6 This is a schematic diagram of the composition and structure of the remote nuclear capacity system of the present invention.

[0021] Figure 7 This is a schematic diagram of the structure of the remote discharge control box of the present invention.

[0022] Figure 8 This is a schematic diagram of the consumable load capacity module of the present invention.

[0023] Figure 9 This is a schematic diagram of a single-tube constant current unit in the MOS transistor combination Q of the constant current control section of the present invention.

[0024] Figure 10 This is an internal schematic diagram of the feed-type discharge module of the present invention.

[0025] Figure 11 This is a flowchart illustrating the overall operation of the remote nuclear capacity system of the present invention.

[0026] Figure 12 This is a flowchart of the operation mode of the remote nuclear capacity system of the present invention.

[0027] Figure 13 This is a flowchart of the second operating mode of the remote nuclear capacity system of the present invention.

[0028] Figure 14 This is a flowchart of the three operating modes of the remote nuclear capacity system of the present invention.

[0029] Figure 15 This is a schematic diagram of the nuclear capacity device structure in the fourth embodiment of the present invention.

[0030] Figure 16 This is a circuit diagram of the intelligent variable resistance box of the present invention.

[0031] Figure 17 This is a circuit diagram of the current detection unit of the present invention.

[0032] Figure 18 This is a flowchart of the voltage-based intelligent battery diagnostic process of the present invention.

[0033] Figure 19 This is a flowchart of the automatic nuclear capacity test control of the present invention. Detailed Implementation

[0034] The present invention will be further described below with reference to the embodiments and / or accompanying drawings.

[0035] Example 1

[0036] like Figure 1-2As shown, a remote capacity verification and uninterrupted power-off battery replacement device for DC battery banks in substations includes a junction box, a controller U1, and a remote capacity verification system. Both the junction box and the remote capacity verification system are connected to the controller U1. The junction box contains a test circuit, a main circuit, two parallel multi-head quick-connect terminals, and a display circuit. It also includes an audible and visual alarm connected in series with the test circuit. The display circuit is connected to a display screen. The controller U1's input terminal is connected to a reference voltage unit that provides a reference voltage to the controller U1 and a measuring unit for measuring battery voltage. A battery short-circuit unit is connected to the input terminal of the measuring unit. The battery short-circuit unit uses an optocoupler-isolated drive circuit connected to the controller U1. The remote capacity verification system includes a capacity management platform, a battery management module, a capacity verification module, and a remote discharge control box. The battery management module is connected to the capacity verification module, the capacity management platform, and multiple remote discharge control boxes. The capacity verification module is connected to the battery bank.

[0037] In this embodiment, the two parallel multi-head quick-connect terminals serve the following functions:

[0038] ① Connect the power supply from the top of the main fuse at the bottom of the cabinet to the junction box. Since the quick connector of the junction box is not connected to the temporary battery at this time, sparking and voltage instability are avoided during operation.

[0039] ② When assessing the battery capacity, provide multiple terminals to the capacity assessor to meet the sampling requirements of the test clamp.

[0040] ③ The junction box can be easily removed, and the wires can be retracted and placed inside the device, protecting the junction box leads and facilitating transportation.

[0041] The positive and negative terminals of the test circuit are parallel to the positive and negative terminals of the junction box. The test circuit is also equipped with an audible and visual alarm connected in series with the test circuit. The positive and negative terminals of the test circuit are parallel to the positive and negative terminals of the main circuit and are electrically independent.

[0042] In this embodiment, the function of the test circuit is to test the connection of the two terminals of the faulty battery with the same polarity before using the main circuit to bridge the damaged faulty battery. If the polarity is reversed, there will be an audible and visual alarm to remind the staff that the position is wrong.

[0043] The main circuit has two DC fast terminals for both positive and negative terminals, and a current shunt is connected in series in the main circuit. The current shunt is connected in parallel with the display circuit. The display circuit is connected to the display screen, which displays the current parameters passing through the main circuit and monitors in real time whether the online battery pack is interrupted.

[0044] In this embodiment, the present invention aims to replace a running battery without power interruption. This requires bridging the faulty battery while maintaining the main circuit continuity. The workflow is as follows:

[0045] Step 1: Determine the positions of the batteries before and after the faulty battery.

[0046] Step 2: To ensure that there is no short circuit between the front and rear batteries of the jump-connected battery, the positive terminal of the front battery of the jump-connected battery should be connected to the negative terminal of the main circuit of the junction box, and the negative terminal of the rear battery of the jump-connected battery should be connected to the positive terminal of the main circuit of the junction box.

[0047] Step 3: To prevent incorrect wiring during bridging, a test circuit must be used to test the terminals of the battery before and after the faulty battery before wiring.

[0048] Step 4: After isolating the faulty battery by bridging, remove it and monitor the current flowing through the battery pack in real time during the operation to ensure that the bridging circuit is working properly.

[0049] In summary, the economic benefits of this invention are as follows: The application of this invention avoids battery explosions caused by incorrect wiring, minimizing personal injury and equipment risks. It also prevents grounding from affecting secondary equipment, ensuring the reliability of the power grid, reducing the number of workers, and saving 1000 yuan per instance in labor costs. The social benefits include: reducing the risks for workers repairing energized equipment; improving work efficiency by displaying current in real-time on a screen, eliminating the need for a dedicated current clamper, reducing manpower and material resources, and achieving efficient workload reduction; and reducing the operational risks of automation and protection equipment in DC load substations during DC system battery maintenance.

[0050] This invention is a device for remote capacity assessment and uninterrupted replacement of failed DC battery banks in substations. In use, this invention prioritizes high reliability, employing an audible and visual alarm function in the test circuit to prevent human error and achieve 100% wiring accuracy. By adding terminals, it relocates congested internal DC wiring locations to an external junction box, improving operational and equipment safety. Through a built-in module, it samples voltage and current in real time to confirm wiring reliability and allows for real-time monitoring of operational status. This invention effectively solves the problem of manually determining the polarity of the battery before connection and the polarity of the battery to be replaced. This invention offers advantages such as applicability to single or multiple parallel battery banks, remote capacity assessment without power outages, accurate polarity determination, and improved work efficiency.

[0051] Example 2

[0052] like Figure 3-5As shown, a remote capacity verification and uninterrupted power-off battery replacement device for DC battery banks in substations includes a junction box, a controller U1, and a remote capacity verification system. Both the junction box and the remote capacity verification system are connected to the controller U1. The junction box contains a test circuit, a main circuit, two parallel multi-head quick-connect terminals, and a display circuit. It also includes an audible and visual alarm connected in series with the test circuit. The display circuit is connected to a display screen. The controller U1's input terminal is connected to a reference voltage unit that provides a reference voltage to the controller U1 and a measuring unit for measuring battery voltage. A battery short-circuit unit is connected to the input terminal of the measuring unit. The battery short-circuit unit uses an optocoupler-isolated drive circuit connected to the controller U1. The remote capacity verification system includes a capacity management platform, a battery management module, a capacity verification module, and a remote discharge control box. The battery management module is connected to the capacity verification module, the capacity management platform, and multiple remote discharge control boxes. The capacity verification module is connected to the battery bank.

[0053] The reference voltage unit connected to the input terminal of the controller U1 includes: resistor R1, resistor R3 connected in series with resistor R1, and capacitor C4 connected in parallel with resistor R1. One end of resistor R1 is grounded, and the other end is connected to the input terminal of controller U1 and connected to a high level through resistor R3.

[0054] The measurement unit connected to the input terminal of the controller U1 includes: resistor R7, resistor R8 and diode VD1. One end of resistor R7 is connected to the input terminal of controller U1, and the other end is grounded through diode VD1 and connected to the anode of thyristor VS through resistor R8.

[0055] The controller U1 also includes an alarm unit, which includes indicator lights H1, H2, and H3. The positive terminal of indicator light H1 is connected to a high level, and the negative terminal is connected to the controller U1 via resistor R4 and to the cathode of thyristor VS via resistor R4. The alarm function of the alarm unit is indicated by indicator lights.

[0056] The controller U1 also includes an anti-misoperation unit, a power supply unit, a status display unit, a voltage sampling circuit, and a bridging unit.

[0057] In this embodiment, ① Status display unit: can display the working status of the replaced jump-connected working battery, including parameter information such as voltage and current.

[0058] The main function of the battery voltage test is to detect the voltage of the entire battery pack. The test system mainly consists of a detection circuit, a 16-bit A / D conversion module, and an integrated board. First, the collected battery voltage is amplified and filtered, and then input into the integrated board after A / D conversion. The integrated board encodes the data and transmits it through communication with the main circuit of the device. Finally, the data is displayed on the screen.

[0059] Meanwhile, to ensure the integrity and stability of voltage measurements, the module incorporates an SPPM voltage reference source and a 16-bit high-speed A / D converter chip. These components ensure that the voltage measurement error is less than 0.1 ohms and address the issue of temperature drift. Its working principle is as follows: Figure 4 As shown.

[0060] ② Voltage Sampling Circuit: To ensure the system operates normally and orderly, and to guarantee the accuracy and integrity of voltage detection, the voltage sampling circuit uses a linear optocoupler isolation chip HCNR201. It consists of an AIGASLED and two photodiodes PD1 and PD2. PD1's main function is to suppress light drift emitted by the LED, improve the linearity of the LED light, and monitor the intensity of the emitted light. PD2 photodiode is used to emit a photocurrent proportional to the intensity of the LED light. Because PD1 and PD2 are in the same chip and their characteristics are almost identical, when the LED emits light, both photodiodes PD1 and PD2 can simultaneously receive the light from the LED, and the received amounts are proportional. This effectively avoids unnecessary external influences, ensuring good and stable linearity. The voltage sampling circuit diagram is shown below. Figure 5 As shown.

[0061] ③ The method for monitoring the battery current is to collect the current by embedding an integrated current transformer. Specifically, a current transformer of appropriate capacity is installed on the positive and negative buses of the device's test circuit. The detected current value is then converted by an A / D conversion chip, and the resulting data is displayed on the monitoring system.

[0062] ④ Jumper Unit: This invention employs a gapless jumper method for failed batteries, providing an additional current path Is for the circuit of the faulty battery (E2). When the battery bank is operating, the total current of the entire battery bank is IA. If one of the batteries fails (assumed to be E2), the current IE through the faulty battery E2 will decrease due to the increase in its internal resistance Rb2. At this time, another current path Is is provided to controllably shunt the current IA, resulting in the expression IA = Is + IE. This completes the gapless automatic jumper for the faulty battery, fundamentally eliminating the adverse effects on the entire power grid caused by a sudden failure of a battery, and ensuring the reliability and safety of the power grid to the greatest extent.

[0063] The anti-misoperation unit includes diodes VD2 and VD3, and an optocoupler isolation module U2. The VCC terminal of the optocoupler isolation module U2 is connected to the power supply terminal Vcc (+5V), the GND terminal is grounded, the A terminal is connected to the power supply terminal Vcc (+5V) via resistor R2, the K terminal is connected to the P1.5 terminal of the controller U1, and the VO terminal is connected to the control electrode (G) of the thyristor VS via resistor R9. The negative terminal of diode VD2 is connected to the control electrode (G) of the thyristor VS, and the positive terminal is connected to the positive terminal of diode VD3. The negative terminal of diode VD3 is connected to the cathode (K) of the thyristor VS, and the negative terminal is grounded. The cathode (K) of the thyristor VS is connected to the negative terminal of the battery, and the anode (A) is connected to the positive terminal of the battery.

[0064] In this embodiment, the anti-misoperation unit mainly functions as a positive and negative phase voltage stabilization clamp.

[0065] The power supply unit includes a DC-DC power converter U3 and a fuse F1; the Vin- terminal of the DC-DC power converter U3 is connected to the negative terminal of a 12V high-performance lithium battery, and the Vin+ terminal is connected to the positive terminal of the 12V high-performance lithium battery via the fuse F1; a polarized capacitor C1 and a capacitor C2 are provided between the Vin- terminal and the Vin+ terminal, and a polarized capacitor C3 and a capacitor C5 are provided between the COM terminal and the Vo+ terminal; the positive terminal of the polarized capacitor C3 is connected to the power supply terminal Vcc (+5V), and the negative terminal is grounded.

[0066] In this embodiment, the power supply unit is as follows: Figure 3 As shown, the 12V voltage of the 12V high-performance lithium battery is stepped down to 5V by the DC-DC power converter U3, and the stepped-down 5V voltage is used to supply power to the jumper device. This achieves the goal of safely disconnecting or replacing the tested battery and putting it back into operation without affecting the continuous power supply of the DC system.

[0067] In summary, this invention is equivalent to a unidirectional diode with reverse withstand voltage, ensuring that the replaced battery is bypassed. When a battery in the substation's battery bank fails, directly connecting the device of this invention bypasses the faulty battery without causing an internal short circuit or power loss in the battery bank. When a battery in the battery bank fails and the power supply cannot be disconnected, the method for handling the battery failure is to connect a battery in series with this invention and then connect it in parallel across the terminals of the faulty battery, effectively replacing the faulty battery. The total voltage of the battery bank remains unchanged, and the battery bank can operate normally after the failure is resolved. This invention can be performed in the following three states:

[0068] ① The battery pack is not disconnected from the charger. When the battery pack is in float charging state, the faulty battery is directly replaced.

[0069] ② If the charger input fails or the charger malfunctions during the replacement process, the faulty battery can be directly replaced.

[0070] ③ If a high-power reclosing device is activated during the replacement process, the faulty battery can be directly replaced.

[0071] This invention is a remote capacity assessment and uninterrupted power-off battery replacement device for DC battery banks in substations. In use, this invention can perform online or offline measurements, connecting between batteries as a battery bypass connection. It offers high safety and excellent insulation, eliminating interference from electromagnetic interference, ripple current, parasitic capacitance, and other sources. This invention can withstand high-current discharge, ensuring safety and reliability. It features automatic battery orientation identification and analysis, allowing for online replacement of individual deteriorated batteries without needing to remove the battery bank from operation. This invention offers advantages such as applicability to single or multiple parallel battery banks, remote capacity assessment without power outages, determination of wiring polarity, and improved work efficiency.

[0072] Example 3

[0073] like Figure 6-14As shown, a remote capacity verification and uninterrupted power-off battery replacement device for DC battery banks in substations includes a junction box, a controller U1, and a remote capacity verification system. Both the junction box and the remote capacity verification system are connected to the controller U1. The junction box contains a test circuit, a main circuit, two parallel multi-head quick-connect terminals, and a display circuit. It also includes an audible and visual alarm connected in series with the test circuit. The display circuit is connected to a display screen. The controller U1's input terminal is connected to a reference voltage unit that provides a reference voltage to the controller U1 and a measuring unit for measuring battery voltage. A battery short-circuit unit is connected to the input terminal of the measuring unit. The battery short-circuit unit uses an optocoupler-isolated drive circuit connected to the controller U1. The remote capacity verification system includes a capacity management platform, a battery management module, a capacity verification module, and a remote discharge control box. The battery management module is connected to the capacity verification module, the capacity management platform, and multiple remote discharge control boxes. The capacity verification module is connected to the battery bank.

[0074] In this embodiment, for battery banks experiencing insufficient capacity during long-term operation, requiring capacity verification, or when individual battery parameters change (e.g., insufficient capacity, excessive internal resistance, abnormal terminal voltage), or when individual batteries are damaged by external forces, connection stress, or casing breakage, it is necessary to separate and replace individual batteries from the system. For example, before verifying the capacity of a 110kV substation, a temporary battery bank with the same polarity connection needs to be connected in parallel to the load side of the battery bank to be verified, and then the fuse is opened to isolate the battery bank to be verified. This invention can achieve uninterrupted replacement and remote capacity verification of battery banks. The structure of its remote capacity verification system is as follows: Figure 6 As shown.

[0075] Furthermore, the remote discharge control box of the remote capacity system includes diode D1, diode D2, switch K, fault diagnosis module, and current input / output terminal. The fault diagnosis module is connected to the power supply terminal and the communication terminal respectively, and the fault diagnosis module is connected in parallel with diode D1, diode D2 and switch K in sequence and then connected to the current input / output terminal.

[0076] In this embodiment, the remote discharge control box is structured as follows: Figure 7 As shown, a fault diagnosis mechanism for the remote discharge control box is introduced. Under normal circumstances, the forward voltage drop of the selected power diode is 0.5V, and the voltage drop under rated current is 1.6V. The closed contact resistance of the selected DC contactor is generally around 1mΩ. Based on this diagnostic mechanism, it is possible to determine whether there is a fault in the diode and the contactor (i.e., switch K), as shown in Table 1.

[0077] Table 1 Fault Diagnosis Table for Remote Discharge Control Box

[0078]

[0079] When 0.2V < U d When the voltage is <1.6V, the control switch K is closed: if U d If the voltage is ≤0.2V, it can be determined that switch K is normal and diode is normal; if 0.2V < U d If the voltage is less than 1.6V, it can be determined that switch K is abnormal, while the diode is normal.

[0080] When U d When the voltage is ≥1.6V, the control switch K is closed: if U d If the voltage is ≤0.2V, it can be determined that switch K is normal and diode is abnormal; if U d A voltage ≥1.6V indicates an abnormality in switch K and diode.

[0081] When U d When the voltage is ≤0.2V, the control switch K is open: if U d If the voltage is ≤0.2V, switch K is considered faulty; if 0.2V < U... d If the voltage is <1.6V, it can be determined that switch K is normal and diode is normal; if U d If the voltage is ≥1.6V, it can be determined that switch K is normal and diode is abnormal.

[0082] Based on the above working principle, remote discharge control box KD status detection can be achieved.

[0083] As one possible specific implementation method, ① remote core capacity module: such as Figure 8 As shown, in the design of a pure consumable load capacity module, the load can be formed by multiple resistor bars connected in parallel according to the equipment model requirements. The resistor bars are made of nickel-chromium flat wire (Cr20Ni80) and can withstand a current of about 10A. If the final requirement of the equipment is to withstand a current of 50A, it can be formed by 5 resistor bars connected in parallel.

[0084] In practical applications, the power consumption of a single transistor can be reduced by increasing the number of MOSFETs, i.e., increasing the heat dissipation area by increasing the number of MOSFETs, each driven independently by a constant current circuit. This invention uses six identical single-transistor constant current units, with node P+ connected in parallel, node A connected in parallel with an adjustable constant current branch negative feedback circuit, and node B grounded and connected to a current sampling resistor, such as... Figure 9 As shown; when current flows through, a voltage signal is generated on the current sampling resistor. This signal is amplified and compared with the current reference voltage. The amplified signal is then output to point A as the turn-on voltage of the control MOSFET, which in turn controls the corresponding on-resistance, and finally controls the branch current.

[0085] Furthermore, the novel feed-type discharge module of this invention mainly consists of a purely resistive dummy load PTC and a power supply module DC / DC, etc. Figure 10As shown, this DC / DC converter adopts a constant current mode BOOST topology, which can raise the voltage that is constantly decreasing during the capacitance process to slightly higher than the charger output voltage, ensuring the stability of the power supply voltage of the DC load. During the capacitance process, the actual load is used for capacitance first, while the dummy load PTC is in the off state. The current is supplied after being boosted by the DC / DC converter. When the actual load cannot meet the discharge current requirement, the dummy load is activated according to the missing current.

[0086] Without adjusting the charger output voltage during the capacity testing process, the tested battery pack can provide constant current power to the actual load to achieve online constant current discharge. Moreover, during this process, another battery pack is always kept in a full float charge backup state, minimizing the risk of system failure during discharge.

[0087] ② Remote Capacity Approval System Operation Flow: Under the floating charge operation of the battery pack, the battery pack discharge switches (K1, K2) and bus tie switch K3 in the capacity approval module should be in the open state, and the battery pack output switches (J1, J2) in the remote discharge control box should be in the closed state. The capacity approval management platform has basic functions such as telemetry, remote signaling, remote control, and remote adjustment, such as selecting the capacity approval battery pack, setting parameters such as capacity approval discharge current, discharge capacity, and discharge time, and setting alarm thresholds such as temperature, current, and voltage. First, select the battery pack to be remotely approved through the capacity approval management platform. After confirming that there are no abnormal alarms, select full capacity or set capacity (or duration) according to the plan and set the capacity approval parameters. Second, the battery management module controls the battery pack output switch in the remote discharge control box to open according to the command, so that the battery pack stops charging and stops supplying power to the DC system. Close the battery pack discharge switch to start the load module to discharge. The battery remote capacity approval platform issues a command to start the discharge module to discharge the battery pack. The basic flow of the whole process is as follows: Figure 11 As shown.

[0088] ③ Mode 1: Normal capacity assessment process. If no AC power failure occurs, the capacity analysis results will be output after the process ends. Then, the battery circuit recovery process (i.e., charging) will begin. After the load module exits, the battery pack will charge while simultaneously supplying power to the DC system. Figure 12 As shown.

[0089] ④ Mode Two: If AC power loss occurs during capacity verification, capacity verification is immediately stopped, and the system enters the safe operation phase. Capacity verification resumes according to the plan once AC power is restored and the battery charge recovery process begins. Specifically, when the start-up conditions for multiple output checks are met, such as determining, based on the discharged capacity and individual cell voltage and distribution, that a single cell may not be able to continue supporting power for an extended period, the bus tie switch is closed, and the battery pack output switch in the remote discharge control box is in the open state. The battery pack supplies power to the DC system through diodes. AC power is monitored in real-time; if restored, the bus tie switch is disconnected, controlling the battery pack charging while simultaneously supplying power to the DC system. Figure 13 As shown.

[0090] ⑤ Mode 3: If AC power fails during charging after normal capacity verification, the system immediately enters the phase of ensuring safe operation. Once AC power is restored, the battery charging process resumes. After fully charged, capacity verification can proceed according to plan. Figure 14 As shown. During the charging process after the end of the core capacity, if AC power loss occurs, and the start-up conditions for multiple outputs are met, the judgment method is similar to that of Mode 2. Based on the charging curve, it is determined whether a single group can no longer support the system for a long time. When the start-up conditions are met, the system controls multiple groups to output simultaneously and monitors in real time whether AC power is restored.

[0091] This invention relates to a remote capacity verification and uninterrupted power replacement device for DC battery banks in substations. Currently, most substation DC systems still rely on manual on-site capacity verification of battery banks, requiring significant manpower and resources annually to check their health. This invention's remote capacity verification system, equipped with protective features, will not experience power outages due to AC power failure when remotely verifying capacity away from the DC bus. It also allows for early detection of any abnormalities in the remote control box itself. This invention offers advantages such as applicability to single or multiple parallel battery banks, remote capacity verification avoiding power outages, ability to determine wiring polarity, and improved work efficiency.

[0092] Example 4

[0093] like Figure 15-19As shown, a remote capacity verification and uninterrupted power-off battery replacement device for DC battery banks in substations includes a junction box, a controller U1, and a remote capacity verification system. Both the junction box and the remote capacity verification system are connected to the controller U1. The junction box contains a test circuit, a main circuit, two parallel multi-head quick-connect terminals, and a display circuit. It also includes an audible and visual alarm connected in series with the test circuit. The display circuit is connected to a display screen. The controller U1's input terminal is connected to a reference voltage unit that provides a reference voltage to the controller U1 and a measuring unit for measuring battery voltage. A battery short-circuit unit is connected to the input terminal of the measuring unit. The battery short-circuit unit uses an optocoupler-isolated drive circuit connected to the controller U1. The remote capacity verification system includes a capacity management platform, a battery management module, a capacity verification module, and a remote discharge control box. The battery management module is connected to the capacity verification module, the capacity management platform, and multiple remote discharge control boxes. The capacity verification module is connected to the battery bank.

[0094] This embodiment is basically the same as embodiment 3, except that the nuclear capacity module of the remote nuclear capacity system in embodiment 3 is replaced by a nuclear capacity device, as detailed below.

[0095] As another possible specific implementation, the nuclear capacity device: such as Figure 15 As shown, it mainly consists of three parts: a programmable resistor box, a main controller, and a current detection unit. The current detection unit realizes real-time current detection of the discharge circuit, providing an important basis for the resistance adjustment of the variable resistor box. The intelligent variable resistor box can close or open the discharge circuit according to the control signal fed back by the main controller, automatically connect or disconnect resistors of different resistance values, change the motor rotation to adjust the variable resistor, realize precise resistance adjustment within a certain range, ensure constant discharge current and safe and reliable discharge of the system. The main controller communicates with the DC power supply and the current detection unit to collect and analyze the terminal voltage signal of the battery module and the current signal of the discharge circuit, determine the battery status, realize the opening and closing of the discharge circuit and the resistance adjustment of the variable resistor box through the control circuit interface, and issue an alarm when the system parameters deteriorate. At the same time, it records and stores data such as battery terminal voltage, discharge current, and discharge time.

[0096] Specifically, the main controller is as follows: ① Main controller: The input port of the main controller communicates with the DC power supply to accurately acquire external current signals. Its signal output port accurately controls peripheral devices such as relays. The main controller circuit is designed with the STM32F103ZET6 microcontroller as the core.

[0097] ② Programmable Resistance Box Circuit: The intelligent variable resistance box consists of two parts. One part is a fixed resistor combination circuit, composed of resistors with resistance values ​​of 1Ω, 2Ω, 4Ω, 8Ω, 10Ω, and 20Ω. Adjacent resistors are connected through single-pole double-throw relays, which are controlled by the main controller. The other part is a precisely adjustable resistor composed of a 1Ω sliding rheostat controlled by a stepper motor. Based on this, by adopting appropriate control strategies, the resistance box can automatically change its resistance value within the range of 0.00Ω to 39.99Ω, while simultaneously controlling the switching... Figure 16 The intermediate relay S7 can close and open the discharge circuit to start and stop the discharge test. The relay is required to withstand large current and have low on-resistance. Therefore, the RXM2AB2BD12A DC intermediate relay is used. This relay has low contact resistance to control the discharge resistance.

[0098] ③ Current Detection Unit Circuit: The current detection circuit uses the ACS712 linear current sensor as its core. This chip has a built-in precise low-bias linear Hall sensor circuit, which can output a linear voltage to the detected DC signal. It features low noise, fast response time, and high output sensitivity. Its input current range is ±5A to ±20A, and it can be directly connected in series in a 10A discharge circuit to achieve real-time current monitoring; the circuit diagram is shown below. Figure 17 As shown, the module is connected in series in the main circuit through the V_IN and V_OUT ports, and communicates with the main controller through the I0_OUT interface.

[0099] ④ Capacity Control Strategy: Voltage-Based Intelligent Battery Diagnosis Rules and Procedures: The system acquires the terminal voltage of each battery through a DC power supply, collects and records battery voltage parameters, and performs intelligent battery diagnosis. During discharge, the system records the battery voltage value in real time and compares it with a predetermined voltage threshold, analyzing the voltage data. Assuming the terminal voltage of the i-th battery at time t is u... t The lower limit voltage of the battery is U. N Under normal discharge conditions, the rate of change of battery voltage is ΔU N The actual rate of change of battery voltage Δu can be obtained from the following formula. t : When u t =U N When the battery voltage reaches its lower voltage limit, the system should disconnect.

[0100] The electrical circuit stops discharging and issues an alarm signal; when Δu t <<ΔU N or Δu t >>ΔU NWhen the voltage value changes abruptly or too rapidly, the battery malfunctions, automatically terminates the discharge, disconnects the discharge circuit, and issues an alarm signal to protect the battery and prevent secondary damage from capacity failure. Voltage-based intelligent battery diagnostic control strategies include... Figure 18 As shown.

[0101] ⑤ Current and voltage dual closed-loop discharge control strategy: This invention adopts a voltage and current dual closed-loop charge and discharge control strategy to realize automatic constant current discharge and discharge cessation of the battery; specifically as follows: During the discharge process of the capacity test, the battery pack voltage, loop current and the voltage of each battery are cyclically detected in sequence. The intelligent variable resistor box is quickly set to the integer resistance value corresponding to the 10A current according to the battery pack terminal voltage value. Then, according to the loop discharge current value, the decimal resistance value of the intelligent variable resistor box is adjusted until the current is equal to 10A. At the same time, according to the real-time battery voltage value, the battery condition is intelligently diagnosed and corresponding operations are performed to ensure battery safety and accurate and reliable capacity test results.

[0102] ⑥ BCD Code-Based Programmable Resistor Box Control Strategy: This invention employs a BCD code-based variable resistor control strategy to achieve resistance adjustment; combined with... Figure 17 The circuit uses a main controller to control the switching position of a single-pole double-throw relay. Resistors with resistances of 1Ω, 2Ω, 4Ω, and 8Ω are connected in series. Using BCD binary code rules, the total resistance is varied from 0 to 9Ω (units digit). This is then combined with a 10Ω or 20Ω resistor to achieve a total resistance range of 0 to 39Ω. Simultaneously, by controlling the stepper motor, the resistance of a sliding rheostat is precisely changed, allowing for precise adjustment of the total resistance within the range of 0.00Ω to 39.99Ω. The resistance values ​​from 0 to 9 are encoded as shown in Table 2, where 0 indicates the resistor is disconnected in the circuit, and 1 indicates the resistor is connected in the circuit.

[0103] Table 2. Integer Resistance Values ​​and BCD Code Control Table for Variable Resistors

[0104]

[0105]

[0106] ⑦ Device control strategy: Flowchart of automated capacity testing is shown below. Figure 19 As shown, after the battery capacity test begins, the capacity testing device first detects the battery pack terminal voltage, quickly sets the resistance value of the intelligent variable resistor box, then closes the circuit to start discharging, detects the discharge current value, and continues to adjust the resistance value of the resistor box until the current equals 10 amperes; then, it monitors the terminal voltage of each battery cell in real time to determine whether it has dropped to the lower voltage limit. If the terminal voltage of any battery module drops to the lower voltage limit, it switches... Figure 16The S7 relay switch disconnects the main circuit, stops the discharge, and switches the relay in the battery control circuit to remove the battery cell. The discharge time is recorded. After inspecting all battery cells, S7 is closed, the resistance box value is reset, and the discharge continues until all batteries are discharged within a cumulative 10 hours. The capacity of each battery is calculated based on the recorded discharge time, thus achieving the full capacity of the battery pack.

[0107] This invention relates to a remote capacity verification and uninterrupted power-off battery replacement device for DC battery banks in substations. In use, the verification device acquires real-time discharge voltage and discharge circuit current signals from the battery modules and controls a programmable resistor box to achieve constant DC discharge. This invention identifies and automatically stops discharging over-limit battery modules by formulating and applying voltage-based intelligent battery diagnostic rules, reducing secondary damage during battery capacity verification. By automatically recording and storing real-time waveforms of discharge current and battery terminal voltage during the capacity verification process, this invention can automatically diagnose and identify over-limit batteries, intelligently stop discharge, alarm, and record early warning events, ensuring the authenticity and reliability of the capacity verification test data and meeting the 10-hour rate capacity verification requirements of typical 100V or 220V DC power supply battery banks in substations. This invention has advantages such as applicability to single or multiple parallel systems, remote capacity verification without power outages, ability to determine wiring polarity, and improved work efficiency.

Claims

1. A device for remote capacity verification and uninterrupted power replacement of DC battery banks in substations, comprising a junction box, a controller U1, and a remote capacity verification system, wherein both the junction box and the remote capacity verification system are connected to the controller U1, characterized in that: The junction box is internally provided with a group of test circuits, a group of main through circuits, two parallel multi-head quick connecting posts and a display circuit, and is simultaneously provided with an audible and visual alarm connected in series with the test circuit, and the display circuit is connected with a display screen; the input end of the controller U1 is connected with a reference voltage unit for providing reference voltage for the controller U1 and a measuring unit for measuring the voltage of the storage battery, and a battery short circuit unit is connected at the input end of the measuring unit, and the battery short circuit unit is connected with the controller U1 through an optical coupling isolation driving circuit; the remote nuclear capacity system comprises a nuclear capacity management platform, a battery management module, a nuclear capacity module and a remote discharge control box, the battery management module is connected with the nuclear capacity module, the nuclear capacity management platform and a plurality of remote discharge control boxes respectively, and the nuclear capacity module is connected with the storage battery pack.

2. The substation DC battery bank remote capacity and failed battery hot swap device of claim 1, wherein: The positive and negative output lines of the test circuit are parallel with the positive and negative output lines of the junction box, the test circuit is further provided with an audible and visual alarm connected in series with the test circuit, and the positive and negative output lines of the test circuit are parallel with and electrically independent of the positive and negative output lines of the main through circuit.

3. The substation DC battery bank remote capacity check and fail battery hot swap device of claim 2, wherein: The main through circuit has two DC quick connecting posts for each of the positive and negative poles, and a current shunt is connected in series in the main through circuit, and the current shunt is connected in parallel with the display circuit; the display circuit is connected with a display screen, the display screen displays the current parameters passing through the main through circuit, and the online storage battery pack is monitored in real time whether to interrupt the work.

4. The substation DC battery bank remote capacity and failed battery hot swap device of claim 1, wherein: The reference voltage unit connected with the input end of the controller U1 comprises a resistor R1, a resistor R3 connected in series with the resistor R1 and a capacitor C4 connected in parallel with the resistor R1, one end of the resistor R1 is grounded, the other end is connected with the input end of the controller U1 and is connected with high level through the resistor R3.

5. The substation DC battery bank remote capacity check and fail cell hot swap device of claim 4, wherein: The measuring unit connected with the input end of the controller U1 comprises a resistor R7, a resistor R8 and a diode VD1, one end of the resistor R7 is connected with the input end of the controller U1, the other end is grounded through the diode VD1 and is connected with the anode of a thyristor VS through the resistor R8.

6. The substation DC battery bank remote capacity check and fail cell hot swap device of claim 5, wherein: The controller U1 further comprises an alarm unit, the alarm unit comprises indicator lamps H1, H2 and H3, the positive pole of the indicator lamp H1 is connected with high level, the negative pole is connected with the controller U1 through a resistor R4 and is connected with the cathode of the thyristor VS through the resistor R4; the alarm form of the alarm unit is to prompt through the indicator lamp.

7. The substation DC battery bank remote capacity check and fail cell hot swap device of claim 6, wherein: The controller U1 further comprises an anti-misoperation unit, a power supply unit, a state display unit, a voltage sampling circuit and a cross connection unit.

8. The substation DC battery bank remote capacity and failed battery hot swap device of claim 7, wherein: The anti-misoperation unit comprises a diode VD2, a diode VD3 and an optical coupling isolation module U2; the VCC end of the optical coupling isolation module U2 is connected with a power supply end Vcc, the GND end is grounded, the A end is connected with the power supply end Vcc through a resistor R2, the K end is connected with the P1.5 end of the controller U1, the VO end is connected with the control electrode of the thyristor VS through a resistor R9; the negative pole of the diode VD2 is connected with the control electrode of the thyristor VS, and the positive pole is connected with the positive pole of the diode VD3; the negative pole of the diode VD3 is connected with the cathode of the thyristor VS, and the negative pole is grounded; the cathode of the thyristor VS is connected with the negative pole of the storage battery, and the anode is connected with the positive pole of the storage battery.

9. The substation DC battery bank remote capacity and failed battery replacement without power interruption device of claim 7, wherein: The power supply unit comprises a DC-DC power converter U3 and a fuse F1; the Vin- end of the DC-DC power converter U3 is connected with the negative pole of the lithium battery, the Vin+ end is connected with the positive pole of the lithium battery through the fuse F1, the polarity capacitor C1 and the capacitor C2 are arranged between the Vin- end and the Vin+ end, the polarity capacitor C3 and the capacitor C5 are arranged between the COM end and the Vo+ end; the positive pole of the polarity capacitor C3 is connected with the power supply end Vcc, and the negative pole is grounded.

10. The substation DC battery bank remote capacity and failed battery hot swap device of claim 1, wherein: The remote discharge control box of the remote nuclear containment system comprises a diode D1, a diode D2, a switch K, a fault diagnosis module and a current input and output end, the fault diagnosis module is connected with a power supply end and a communication end respectively, and the fault diagnosis module is connected with the current input and output end after being connected with the diode D1, the diode D2 and the switch K in parallel.

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