Storage battery pack output fuse fault emergency recovery device

Abstract

The invention provides a storage battery pack output fuse fault emergency recovery device. The storage battery pack output fuse fault emergency recovery device comprises a fault emergency recovery device body, four detection lines, two direct current contactors and two anti-reverse connection diode groups, the coil voltage end of each direct current contactor is connected in parallel to the two ends of a fuse, and the control end of each direct current contactor is connected with the fault emergency recovery device body; each anti-reverse connection diode group is connected in parallel with a direct current contactor and a fuse; the fault emergency recovery device body is connected with the two ends of the two fuses through the four detection lines; when the storage battery pack discharges, the fault emergency recovery device body detects the voltage difference between the two ends of the two fuses, determines that the fuses are abnormal when detecting that the voltage difference is greater than a voltage threshold value, controls the corresponding DC contactors to act, and ensures that the DC contactors are communicated by the anti-reverse-connection diode group before being communicated with the storage battery pack and the DC bus. And then the direct current contactor is conducted to connect the pipe. According to the invention, the abnormal condition of the output fuse of the storage battery pack can be detected and power supply can be recovered.

Description

Technical Field

[0001] The invention relates to the technical field of storage batteries, and in particular to an emergency recovery device for a storage battery output fuse failure. Background Art

[0002] The DC power supply system of the substation is responsible for providing stable and reliable DC power supply for all station equipment. Secondary equipment such as relay protection devices, telecontrol devices and communication devices mainly rely on the DC power supply system for power supply. Some switches, knife switch mechanism boxes and control power supplies also rely on the DC power supply system for power supply. At this time, the battery pack, as a backup power supply for the DC system, is connected to the DC bus through a set of "positive and negative" fuses to provide power for the DC system when the AC power fails.

[0003] However, in equipment operation and maintenance, the output fuse of the battery pack is not given much attention. Once the fuse is aged or has poor internal contact, it cannot be discovered in time. When there is a large current shock, the fuse will open, causing an accident. Therefore, it is very necessary to monitor whether the battery output fuse is normal.

[0004] However, in the prior art, the monitoring means for the battery output fuse is relatively simple, and it is impossible to realize real-time monitoring of abnormal conditions. In addition, when the fuse is abnormal, the connection between the battery and the DC bus cannot be restored, which easily leads to a voltage loss accident in the DC system. Summary of the invention

[0005] The technical problem to be solved by the embodiments of the present invention is to provide an emergency recovery device for a battery pack output fuse failure, which can detect abnormal conditions of the battery pack output fuse in real time and restore the connection between the battery pack and the DC bus when the fuse is abnormal, so as to avoid a voltage loss accident in the DC system.

[0006] In order to solve the above technical problems, an embodiment of the present invention provides a battery pack output fuse fault emergency recovery device, which is used in a power supply network formed by interconnecting a battery pack, two fuses, a DC bus and a charger; wherein one fuse connects the positive electrode of the battery pack to the positive electrode of the charger and the DC bus respectively, and another fuse connects the negative electrode of the battery pack to the negative electrode of the charger and the DC bus respectively; a fault emergency recovery device body, four detection lines, two DC contactors and two anti-reverse connection diode groups; wherein,

[0007] The coil voltage ends of each DC contactor are connected in parallel to the two ends of a fuse, and the control ends thereof are connected to the main body of the fault emergency recovery device;

[0008] A reverse connection prevention diode group is connected in parallel to a DC contactor and a fuse, and its positive electrode is connected to the positive electrode of the battery group, and its negative electrode is connected to the positive electrode of the charger and the DC bus at the same time;

[0009] Another anti-reverse connection diode group is simultaneously connected to another DC contactor and another fuse, and its positive electrode is simultaneously connected to the negative electrode of the charger and the DC bus, and its negative electrode is connected to the negative electrode of the battery group;

[0010] The fault emergency recovery device body is connected to two ends of a fuse through two detection wires, and is also connected to two ends of another fuse through another two detection wires;

[0011] The fault emergency recovery device body is used to detect the voltage difference between the two ends of the two fuses in real time through the four detection lines when the battery pack is in a discharged state, and when it is detected that the voltage difference between the two ends of any one of the fuses is greater than the preset voltage threshold, it is determined that the fuse with the voltage difference greater than the preset voltage threshold is abnormal, and further control the DC contactor connected in parallel with the abnormal fuse to operate, so that the controlled DC contactor can conduct the battery pack to supply normal power to the DC bus;

[0012] Each anti-reverse polarity diode group is used to instantaneously turn on the battery group to supply normal power to the DC bus when the parallel-connected fuse has an abnormality, until the parallel-connected DC contactor is automatically turned on after being controlled by the fault emergency recovery device body, so that only the parallel-connected DC contactor is turned on by the battery group to supply normal power to the DC bus.

[0013] Wherein, the conduction voltage threshold value of each anti-reverse connection diode group is greater than the conduction voltage value of the fuse and the DC contactor connected in parallel thereto.

[0014] Wherein, each of the anti-reverse connection diode groups is an anti-reverse connection diode; or, each of the anti-reverse connection diode groups is formed by connecting a plurality of anti-reverse connection diodes in series.

[0015] Among them, it also includes: four current transformers; among them,

[0016] The fault emergency recovery device body is connected to two ends of a fuse through two current transformers, and is also connected to two ends of another fuse through another two current transformers;

[0017] The fault emergency recovery device body is also used to perform real-time detection of the currents at both ends of the two fuses through the four current transformers, and when it is detected that the current difference at both ends of any one of the fuses is less than a preset current threshold, it is determined that the battery pack is in a standby non-working state, and further detects the impedances at both ends of the two fuses through the four detection lines, and after detecting that the impedances at both ends of a fuse are greater than a preset resistance threshold, it is determined that the fuse with impedances at both ends greater than the preset resistance threshold is abnormal.

[0018] Wherein, the fault emergency recovery device body is also used to give an audible and visual alarm when any fuse is found to be abnormal.

[0019] Wherein, the fault emergency recovery device body is also used to display the abnormal condition of each fuse and the power supply condition of the battery pack to the DC bus.

[0020] Implementing the embodiments of the present invention has the following beneficial effects:

[0021] The fault emergency recovery device body of the present invention detects the voltage difference between the two ends of the two fuses in real time through four detection lines when the battery pack is in a discharged state, and when it is detected that the voltage difference between the two ends of any one of the fuses is greater than a preset voltage threshold, the fuse is determined to be abnormal, and the parallel DC contactor is further controlled to be turned on to restore the battery pack to supply normal power to the DC bus. In this way, not only can the abnormality of the battery pack output fuse be detected in real time, but also the connection between the battery pack and the DC bus can be restored when the fuse is abnormal, so as to avoid a voltage loss accident in the DC system. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, without paying creative labor, other drawings obtained based on these drawings still belong to the scope of the present invention.

[0023] Figure 1 A connection diagram of a power supply network formed by interconnecting a battery pack, two fuses, a DC bus and a charger provided in an embodiment of the present invention;

[0024] Figure 2 The present invention is a structural diagram of a battery pack output fuse fault emergency recovery device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0025] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings.

[0026] In an embodiment of the present invention, the inventor proposes an emergency recovery device for a battery pack output fuse failure, which is used in a power supply network interconnected by a battery pack, two fuses, a DC bus and a charger, such as Figure 1 As shown. Figure 1 In the embodiment, a fuse connects the positive electrode of the battery pack to the positive electrode of the charger and the DC bus respectively, and another fuse connects the negative electrode of the battery pack to the negative electrode of the charger and the DC bus respectively.

[0027] At this time, if Figure 2 As shown, the battery pack output fuse fault emergency recovery device comprises a fault emergency recovery device body 1, four detection lines 2, two DC contactors 3 and two anti-reverse connection diode groups 4; wherein,

[0028] The coil voltage terminals of each DC contactor 3 are connected in parallel to the two terminals of a fuse, and the control terminals thereof are connected to the main body 1 of the fault emergency recovery device;

[0029] A reverse connection prevention diode group 4 is connected in parallel to a DC contactor 3 and a fuse, and its positive pole (+) is connected to the positive pole (+) of the battery group, and its negative pole (-) is connected to the positive pole (+) of the charger and the DC bus;

[0030] Another anti-reverse connection diode group 4 is connected in parallel to another DC contactor and another fuse, and its positive pole (+) is connected to the negative pole (-) of the charger and the DC bus, and its negative pole (-) is connected to the negative pole (-) of the battery pack;

[0031] The fault emergency recovery device body 1 is connected to both ends of a fuse through two detection lines 2, and is also connected to both ends of another fuse through another two detection lines 2; at this time, the fault emergency recovery device body 3 is used to detect the voltage difference between the two ends of the two fuses in real time through the four detection lines 2 when the battery pack is in a discharged state, and when it is detected that the voltage difference between the two ends of any fuse is greater than a preset voltage threshold (such as 2V), it is determined that the fuse with a voltage difference greater than the preset voltage threshold is abnormal, and the DC contactor 3 connected in parallel with the abnormal fuse is further controlled to operate, so that the DC contactor 3 controlled to operate can conduct the battery pack to supply normal power to the DC bus;

[0032] Each anti-reverse connection diode group 4 is used to instantaneously turn on the battery group to supply normal power to the DC bus when the parallel-connected fuse has an abnormality, until the parallel-connected DC contactor 3 is controlled by the fault emergency recovery device body 1 to be turned on and then automatically cut off, so that only the parallel-connected DC contactor 3 is turned on by the battery group to supply normal power to the DC bus.

[0033] It should be noted that the DC contactor 3 is closed by whether the coil voltage end is energized or not, and is turned on or off. Considering that the DC contactor 3 needs mechanical action of about 100ms to be completely closed and there will be a short power supply interruption when the fuse is abnormal, it is necessary to equip the anti-reverse connection diode group 4 to perform instantaneous conduction during the 100ms or so time to maintain power supply, and immediately cut off after the DC contactor 3 is turned on to keep the DC contactor 3 continuously turned on and powered.

[0034] In the embodiment of the present invention, the conduction voltage threshold value of each anti-reverse polarity diode group 4 is greater than the conduction voltage value of the fuse and DC contactor 3 connected in parallel thereto. In this way, it can be considered that the resistance of the fuse and the DC contactor 3 is much smaller than that of the anti-reverse polarity diode group 4, and under normal circumstances, it is equivalent to a short-circuit connection between the battery group and the DC bus.

[0035] Taking into account the difference in voltage drop of different diodes, each anti-reverse diode group 4 is an anti-reverse diode or is composed of multiple anti-reverse diodes connected in series. For example, when the voltage difference between the two ends of the fuse is 1.5V, the fuse is abnormal, and the voltage drop of a single diode is 1.8V. At this time, the anti-reverse diode group 4 only needs one diode. For another example, when the voltage difference between the two ends of the fuse is 5V, the fuse is abnormal, and the voltage drop of a single diode is 1.8V. At this time, the anti-reverse diode group 4 requires three or more diodes connected in series.

[0036] In the embodiment of the present invention, it is also necessary to consider the situation that when the battery pack is in standby state with no load current, the fuse is abnormally aged due to long-term use. At this time, the battery pack output fuse fault emergency recovery device also needs to make a comprehensive judgment based on the current at both ends of the fuse. Therefore, the battery pack output fuse fault emergency recovery device also includes: four current transformers 5; wherein the fault emergency recovery device body 1 is connected to both ends of a fuse through two current transformers 5, and is also connected to both ends of another fuse through another two current transformers 5;

[0037] At this time, the fault emergency recovery device body 1 is also used to detect the current at both ends of the two fuses in real time through four current transformers 5, and when it is detected that the current difference at both ends of any fuse is less than the preset current threshold (such as a value between [0, 0.01A]), it is determined that the battery pack is in a standby non-working state, and further detects the impedance at both ends of the two fuses through four detection lines 2, and after detecting that the impedance at both ends of a fuse is greater than the preset resistance threshold (such as 100kΩ and above), it is determined that the fuse with impedance at both ends greater than the preset resistance threshold is abnormal. It should be noted that the fault emergency recovery device body 1 switches the four detection lines 2 through a built-in program to detect the impedance or voltage difference at both ends of the two fuses, which is achieved by conventional technical means in this field similar to a multimeter, and the specific content will not be repeated here.

[0038] In an embodiment of the present invention, the battery pack output fuse fault emergency recovery device can also realize abnormal situation alarm and status display. Therefore, the fault emergency recovery device body 1 is also used to make sound and light alarm when any fuse is found to be abnormal; and, it is also used to display the abnormal situation of each fuse and the power supply situation of the battery pack to the DC bus.

[0039] Implementing the embodiments of the present invention has the following beneficial effects:

[0040] The fault emergency recovery device body of the present invention detects the voltage difference between the two ends of the two fuses in real time through four detection lines when the battery pack is in a discharged state, and when it is detected that the voltage difference between the two ends of any one of the fuses is greater than a preset voltage threshold, the fuse is determined to be abnormal, and the parallel DC contactor is further controlled to be turned on to restore the battery pack to supply normal power to the DC bus. In this way, not only can the abnormality of the battery pack output fuse be detected in real time, but also the connection between the battery pack and the DC bus can be restored when the fuse is abnormal, so as to avoid a voltage loss accident in the DC system.

[0041] The above disclosure is only the preferred embodiment of the present invention, which certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. An emergency recovery device for a battery pack output fuse failure, used in a power supply network interconnected by a battery pack, two fuses, a DC bus and a charger; wherein: A fuse connects the positive electrode of the battery pack to the positive electrode of the charger and the DC bus respectively, and another fuse connects the negative electrode of the battery pack to the negative electrode of the charger and the DC bus respectively; it is characterized in that it includes a fault emergency recovery device body, four detection lines, two DC contactors and two anti-reverse connection diode groups; wherein, The coil voltage ends of each DC contactor are connected in parallel to the two ends of a fuse, and the control ends thereof are connected to the main body of the fault emergency recovery device; A reverse connection prevention diode group is connected in parallel to a DC contactor and a fuse, and its positive electrode is connected to the positive electrode of the battery group, and its negative electrode is connected to the positive electrode of the charger and the DC bus at the same time; Another anti-reverse connection diode group is simultaneously connected to another DC contactor and another fuse, and its positive electrode is simultaneously connected to the negative electrode of the charger and the DC bus, and its negative electrode is connected to the negative electrode of the battery group; The fault emergency recovery device body is connected to two ends of a fuse through two detection wires, and is also connected to two ends of another fuse through another two detection wires; The fault emergency recovery device body is used to detect the voltage difference between the two ends of the two fuses in real time through the four detection lines when the battery pack is in a discharged state, and when it is detected that the voltage difference between the two ends of any one of the fuses is greater than the preset voltage threshold, it is determined that the fuse with the voltage difference greater than the preset voltage threshold is abnormal, and further control the DC contactor connected in parallel with the abnormal fuse to operate, so that the controlled DC contactor can conduct the battery pack to supply normal power to the DC bus; Each anti-reverse polarity diode group is used to instantaneously turn on the battery group to supply normal power to the DC bus when the parallel-connected fuse has an abnormality, until the parallel-connected DC contactor is automatically turned on after being controlled by the fault emergency recovery device body, so that only the parallel-connected DC contactor is turned on by the battery group to supply normal power to the DC bus.

2. The battery pack output fuse fault emergency recovery device according to claim 1, characterized in that: The conduction voltage threshold value of each anti-reverse connection diode group is greater than the conduction voltage value of the fuse and the DC contactor connected in parallel.

3. The battery pack output fuse fault emergency recovery device according to claim 2, characterized in that: Each of the anti-reverse connection diode groups is an anti-reverse connection diode; or, each of the anti-reverse connection diode groups is composed of a plurality of anti-reverse connection diodes connected in series.

4. The battery pack output fuse fault emergency recovery device according to claim 3, characterized in that: Also includes: Four current transformers; among them, The fault emergency recovery device body is connected to two ends of a fuse through two current transformers, and is also connected to two ends of another fuse through another two current transformers; The fault emergency recovery device body is also used to perform real-time detection of the currents at both ends of the two fuses through the four current transformers, and when it is detected that the current difference at both ends of any one of the fuses is less than a preset current threshold, it is determined that the battery pack is in a standby non-working state, and further detects the impedances at both ends of the two fuses through the four detection lines, and after detecting that the impedances at both ends of a fuse are greater than a preset resistance threshold, it is determined that the fuse with impedances at both ends greater than the preset resistance threshold is abnormal.

5. The battery pack output fuse fault emergency recovery device according to claim 4, characterized in that: The fault emergency recovery device body is also used to give an audible and visual alarm when any fuse is found to be abnormal.

6. The battery pack output fuse fault emergency recovery device according to claim 5, characterized in that: The fault emergency recovery device body is also used to display the abnormal condition of each fuse and the power supply condition of the battery pack to the DC bus.

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