An intelligent lithium battery voltage equalization system disconnection detection system and detection method

Abstract

The application provides a kind of intelligent lithium battery voltage equalization system broken line detection system and detection method, belong to lithium battery voltage equalization system broken line detection technical field.It solves the problem that the broken line detection method under the existing transformer coil flying equalization mode cannot detect the actual broken line condition.The detection method includes: S1, controller outputs broken line detection signal, controls detection circuit conduction and forms closed detection loop with filter capacitor;S2, voltage acquisition filter capacitor both ends detection voltage, and detection voltage is fed back to controller;S3, controller judges detection voltage, after a certain detection time, if detection voltage is much lower than the normal voltage of battery to be detected, it is determined that the broken line state is;Otherwise, there is no broken line;S4, continue to complete the broken line detection of other batteries to be detected according to steps S1-S3.The detection method has the advantage of accurately detecting the actual broken line condition of battery under the transformer coil flying equalization mode.

Description

Technical Field

[0001] This invention belongs to the field of open circuit detection technology for lithium battery voltage equalization systems, and relates to an intelligent open circuit detection system and detection method for lithium battery voltage equalization systems. Background Technology

[0002] In the lithium battery industry, battery packs currently primarily use series connection of individual battery cells for power supply. However, in practice, individual cells may have low capacity or low charge capacity, leading to voltage imbalances among the cells in the entire battery pack. Prolonged voltage imbalance can damage the entire battery pack, reduce its lifespan, or even cause it to burn out. To address this issue, existing technology uses equalizers to balance the voltage of the individual battery cells in the pack, eliminating voltage imbalances and protecting the entire battery pack. However, most existing equalizers only perform voltage equalization and repair and do not provide feedback on the current connection status of the equalizer. This results in many battery packs having equalizers but failing to achieve the desired voltage equalization. Often, this is due to poor battery wiring connections caused by uncertain operating conditions and installation methods, leading to a lack of detection and preventing equalization from being achieved. This inability to alert the user and the resulting prolonged imbalance can damage the battery, even causing it to burn out.

[0003] To address the issue of undetected battery disconnections, existing methods incorporate a disconnection detection system into the equalizer. This system determines disconnection by monitoring the voltage of individual battery cells to see if they fall within the normal range. However, this approach still has some drawbacks. Especially when the equalizer uses a transformer coil fly-through equalization method, which virtually parallels all batteries to achieve voltage equalization, even if a battery cell experiences a disconnection due to poor contact, this method can still detect the normal-range voltage induced from other battery cells, thus failing to detect the actual disconnection. Summary of the Invention

[0004] The purpose of this invention is to solve the above-mentioned technical problems by proposing an intelligent lithium battery voltage equalization system disconnection detection system and detection method.

[0005] The objective of this invention can be achieved through the following technical solution: A method for detecting disconnection in an intelligent lithium battery voltage equalization system, characterized by comprising the following steps:

[0006] S1. The controller outputs a disconnection detection signal to the detection circuit corresponding to the battery under test, controls the detection circuit to conduct, and forms a closed detection loop with the filter capacitor connected in parallel on the battery under test.

[0007] S2. The voltage acquisition module acquires the detection voltage across the filter capacitor in step S1 above and feeds the detection voltage back to the controller above.

[0008] S3. The controller determines the detection voltage in step S2 above. After a certain detection time, if the detection voltage is much lower than the normal voltage of the battery under test, the battery under test is determined to be in a disconnected state; otherwise, the battery under test is not disconnected.

[0009] S4. Continue to perform the disconnection detection on other batteries to be tested in sequence according to steps S1 to S3 above.

[0010] In the above-mentioned method for detecting disconnection in an intelligent lithium battery voltage balancing system, the disconnection detection signal is a current signal.

[0011] In the above-mentioned method for detecting disconnection in an intelligent lithium battery voltage equalization system, step S1, in which the controller outputs a disconnection detection signal to the detection circuit corresponding to the battery under test, specifically involves:

[0012] The controller outputs the corresponding disconnection detection signal one by one according to the connection position of each battery in the battery pack in sequential order; or, the controller first outputs the disconnection detection signal simultaneously to all batteries located at odd-numbered positions, and then outputs the disconnection detection signal simultaneously to all batteries located at even-numbered positions.

[0013] In the above-mentioned method for detecting open circuits in an intelligent lithium battery voltage balancing system, the detection time is 5 to 10 seconds.

[0014] A smart lithium battery voltage equalization system disconnection detection system includes a controller, a voltage acquisition module, and a battery pack formed by multiple batteries connected in series. Each battery has a filter capacitor connected in parallel across its two ends. The voltage acquisition module is used to acquire the detection voltage across the filter capacitor and feed it back to the controller. The system is characterized by further including a detection circuit system, which includes a number of detection circuits equal to the number of batteries. Each detection circuit corresponds one-to-one with a battery and can form a closed detection loop with the filter capacitor connected in parallel with the corresponding battery. Each detection circuit has a disconnection detection signal control terminal, which is connected to the controller.

[0015] In the aforementioned intelligent lithium battery voltage balancing system disconnection detection system, the controller outputs a disconnection detection signal to the detection circuit corresponding to the battery under test, controls the detection circuit to conduct and form a closed detection loop with the filter capacitor connected in parallel with the battery under test, and receives the detection voltage on the filter capacitor corresponding to the battery under test collected and fed back by the voltage acquisition module. Then, if the detection voltage is much lower than the normal voltage of the battery under test after a certain detection time, the battery under test is determined to be disconnected; otherwise, the battery under test is not disconnected.

[0016] In the aforementioned intelligent lithium battery voltage equalization system disconnection detection system, the controller outputs a disconnection detection signal to the detection circuit corresponding to the battery under test, which can employ the following strategy:

[0017] The controller outputs the corresponding disconnection detection signal one by one according to the connection position of each battery in the battery pack in sequential order; or, the controller first outputs the disconnection detection signal simultaneously to all batteries located at odd-numbered positions, and then outputs the disconnection detection signal simultaneously to all batteries located at even-numbered positions.

[0018] In the aforementioned intelligent lithium battery voltage equalization system disconnection detection system, the battery pack contains 3 to 10 batteries, and the corresponding detection circuit system includes 3 to 10 detection circuits.

[0019] In the aforementioned intelligent lithium battery voltage equalization system disconnection detection system, the detection circuit includes resistors R1, R2, and R3, and transistor Q1. The collector (c) of transistor Q1 is connected to one end of resistor R3, and the other end of resistor R3 and the emitter (e) of transistor Q1 are respectively connected to the two ends of a filter capacitor connected in parallel to the corresponding battery. One end of resistor R1 and one end of resistor R2 are connected to the disconnection detection signal control terminal, and the other ends of resistor R1 and R2 are respectively connected to the emitter (e) and base (b) of transistor Q1.

[0020] In the aforementioned intelligent lithium battery voltage balancing system disconnection detection system, the disconnection detection signal is a current signal.

[0021] Compared with existing technologies, this wire breakage detection system and method have the following advantages:

[0022] 1. By shorting the positive and negative terminals of a single battery cell in the detection circuit and discharging the capacitor and virtual voltage across the cell, if the corresponding single battery cell is disconnected, the detected voltage will drop significantly below the battery voltage until it reaches 0V as the discharge continues. If the corresponding single battery cell is not disconnected, the single battery cell will maintain the voltage across the capacitor as it discharges, and there will be no significant voltage drop for a certain period of time. This allows for accurate detection of battery disconnection using the transformer coil fly-through balancing method, enabling timely detection of circuit problems and preventing damage to the battery pack and equipment.

[0023] 2. The controller can detect disconnections one by one by shorting each battery cell sequentially, or it can detect disconnections first for batteries at odd-numbered positions and then for batteries at even-numbered positions. You can choose one of the two methods to perform the specific disconnection detection method according to the actual situation. During the detection, adjacent batteries will not affect the battery being detected, thereby improving the detection accuracy. Attached Figure Description

[0024] Figure 1 This is the circuit diagram of the detection circuit system in the open circuit detection system of this intelligent lithium battery voltage equalization system.

[0025] Figure 2 This is a flowchart of the disconnection detection method for the intelligent lithium battery voltage balancing system. Detailed Implementation

[0026] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0027] Example 1

[0028] like Figure 1 As shown, this intelligent lithium battery voltage equalization system disconnection detection system includes a controller, a voltage acquisition module, a detection circuit system, and a battery pack formed by multiple batteries connected in series. Each battery has a filter capacitor connected in parallel across its two ends. The voltage acquisition module is used to acquire the detection voltage across the filter capacitor and feed it back to the controller. The voltage acquisition module, the battery pack, and the filter capacitor connected in parallel across the battery are all existing technologies. Their specific working principles and connection methods will not be described in detail.

[0029] Specifically, the detection circuit system includes a number of detection circuits equal to the number of batteries. Each detection circuit corresponds to one battery and forms a closed detection loop with a filter capacitor connected in parallel with the corresponding battery. Each detection circuit has a disconnection detection signal control terminal, which is connected to the controller. The battery pack can have 3 to 10 batteries, and the corresponding detection circuit system includes 3 to 10 detection circuits. In this embodiment, four batteries are connected in series to form a battery pack, and correspondingly, there are also four detection circuits. Figure 1 As shown, each detection circuit includes resistors R1, R2, and R3, and transistor Q1. The collector (c) of transistor Q1 is connected to one end of resistor R3. The other end of resistor R3 and the emitter (e) of transistor Q1 are connected to the two ends of a filter capacitor connected in parallel to the corresponding battery. One end of resistor R1 and one end of resistor R2 are connected to the disconnection detection signal control terminal. The other ends of resistor R1 and the other ends of resistor R2 are connected to the emitter (e) and base (b) of transistor Q1, respectively.

[0030] The specific working principle of its wire breakage detection is as follows:

[0031] When a disconnection detection is required, the controller outputs a disconnection detection signal to the detection circuit corresponding to the battery under test. This controls the detection circuit to conduct and form a closed detection loop with the filter capacitor connected in parallel to the battery under test. The controller can output the disconnection detection signal to the detection circuit corresponding to the battery under test using one of two strategies: First, the controller outputs the corresponding disconnection detection signal one by one according to the connection position of each battery in the battery pack, in sequential order. This method has clear control logic and is simple to implement. Second, the controller outputs the disconnection detection signal simultaneously to all batteries in odd-numbered positions, and then simultaneously to all batteries in even-numbered positions. This method has high detection efficiency, requiring only two detections to complete all detections. Regardless of the method, adjacent batteries will not affect the battery being tested during detection, thus improving detection accuracy.

[0032] Specifically, in this embodiment, such as Figure 1As shown, the disconnection detection signal is a current signal. We will take the output of the corresponding disconnection detection signal one by one as an example. In the figure, the disconnection detection signal control terminals C1, C2, C3 and C4 are connected to the controller respectively. B0 and B1 on the right are connected to the two ends of the filter capacitor corresponding to the first battery. Similarly, B1 and B2, B2 and B3, B3 and B4 are connected to the two ends of the filter capacitors corresponding to the second battery, the third battery and the fourth battery respectively. The controller outputs a detection current to terminal C1, controlling transistor Q1 to conduct. This forms a closed detection loop between transistor Q1, resistor R3, and the parallel filter capacitor on the first battery. The parallel filter capacitor on the first battery discharges through this closed detection loop. If the first battery is not disconnected, it no longer maintains a voltage across the filter capacitor. After a certain period of discharge (e.g., 5-10 seconds), the voltage across the capacitor drops significantly. The acquisition module collects and feeds back the detection voltage across the capacitor to the controller, which determines that the first battery is disconnected. Conversely, if the first battery maintains a relatively constant voltage across the filter capacitor, the detection voltage remains relatively constant, indicating that the first battery is not disconnected. This detection method can be used to detect other batteries similarly (for example, when detecting a disconnection in the second battery, the controller outputs a detection current to terminal C2 and stops inputting a detection current to terminal C1, causing transistor Q1 to disconnect, thus ceasing the disconnection detection for the first battery). This achieves accurate battery disconnection detection using a transformer coil fly-through equalization method, enabling timely detection of circuit problems and preventing damage to the battery pack and equipment.

[0033] Example 2

[0034] This embodiment provides a method for detecting open circuits in an intelligent lithium battery voltage equalization system, such as... Figure 2 As shown, it includes the following steps:

[0035] S1. The controller outputs a disconnection detection signal to the detection circuit corresponding to the battery under test, controls the detection circuit to conduct, and forms a closed detection loop with the filter capacitor connected in parallel on the battery under test.

[0036] Its disconnection detection signal is a current signal; and the controller outputs the disconnection detection signal to the detection circuit corresponding to the battery under test, specifically as follows:

[0037] The controller outputs the corresponding disconnection detection signal one by one according to the connection position of each battery in the battery pack in sequential order; or, the controller first outputs the disconnection detection signal simultaneously to all batteries located at odd-numbered positions, and then outputs the disconnection detection signal simultaneously to all batteries located at even-numbered positions.

[0038] S2. The voltage acquisition module acquires the detection voltage across the filter capacitor in step S1 above and feeds the detection voltage back to the controller above.

[0039] S3. The controller determines the detection voltage in step S2 above. After a certain detection time, if the detection voltage is much lower than the normal voltage of the battery under test, the battery under test is determined to be in a disconnected state; otherwise, the battery under test is not disconnected.

[0040] A certain detection time can be 5 to 10 seconds;

[0041] S4. Continue to perform the disconnection detection on other batteries to be tested in sequence according to steps S1 to S3 above.

[0042] The principle and process of wire breakage detection are the same as those in Example 1, and will not be repeated here.

[0043] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

Claims

1. A method for detecting open circuits in an intelligent lithium battery voltage balancing system, applied to the detection of open circuits in a transformer coil fly-through balancing method, characterized in that, Includes the following steps: S1. The controller outputs a disconnection detection signal to the detection circuit corresponding to the battery under test, controls the detection circuit to conduct, and forms a closed detection loop with the filter capacitor connected in parallel on the battery under test. S2. The voltage acquisition module acquires the detection voltage across the filter capacitor in step S1 above and feeds the detection voltage back to the controller above. S3. The controller determines the detection voltage in step S2 above. After a certain detection time, if the detection voltage is much lower than the normal voltage of the battery under test, the battery under test is determined to be in a disconnected state; otherwise, the battery under test is not disconnected. S4. Continue to perform the disconnection detection on other batteries to be tested in sequence according to steps S1 to S3 above.

2. The method for detecting open circuits in an intelligent lithium battery voltage equalization system according to claim 1, characterized in that, The aforementioned disconnection detection signal is a current signal.

3. A method for detecting open circuits in an intelligent lithium battery voltage equalization system according to claim 1 or 2, characterized in that, In step S1, the controller outputs a disconnection detection signal to the detection circuit corresponding to the battery under test, specifically as follows: The controller outputs the corresponding disconnection detection signal one by one according to the connection position of each battery in the battery pack in sequential order; or, the controller first outputs the disconnection detection signal simultaneously to all batteries located at odd-numbered positions, and then outputs the disconnection detection signal simultaneously to all batteries located at even-numbered positions.

4. The method for detecting open circuits in an intelligent lithium battery voltage equalization system according to claim 3, characterized in that, The specified detection time is 5 to 10 seconds.

5. A smart lithium battery voltage equalization system open circuit detection system, applied to the open circuit detection of batteries in transformer coil fly-through equalization mode, used for the detection method described in any one of claims 1-4, comprising a controller, a voltage acquisition module, and a battery pack formed by multiple batteries connected in series, wherein a filter capacitor is connected in parallel across the two ends of each battery, and the voltage acquisition module is used to acquire the detection voltage across the filter capacitor and feed it back to the controller, characterized in that: It also includes a detection circuit system, which includes a number of detection circuits equal to the number of batteries. Each detection circuit corresponds to one battery and can form a closed detection loop with a filter capacitor connected in parallel with the corresponding battery. Each detection circuit has a disconnection detection signal control terminal and the disconnection detection signal control terminal is connected to the controller.

6. The intelligent lithium battery voltage equalization system disconnection detection system according to claim 5, characterized in that, The controller outputs a disconnection detection signal to the detection circuit corresponding to the battery under test, controls the detection circuit to conduct, and forms a closed detection loop with the filter capacitor connected in parallel with the battery under test. It also receives the detection voltage on the filter capacitor corresponding to the battery under test from the voltage acquisition module. After a certain detection time, if the detection voltage is much lower than the normal voltage of the battery under test, the battery under test is determined to be disconnected; otherwise, the battery under test is not disconnected.

7. A disconnection detection system for an intelligent lithium battery voltage equalization system according to claim 5 or 6, characterized in that, The controller outputs a disconnection detection signal to the detection circuit corresponding to the battery under test using the following strategy: The controller outputs the corresponding disconnection detection signal one by one according to the connection position of each battery in the battery pack in sequential order; or, the controller first outputs the disconnection detection signal simultaneously to all batteries located at odd-numbered positions, and then outputs the disconnection detection signal simultaneously to all batteries located at even-numbered positions.

8. The intelligent lithium battery voltage equalization system disconnection detection system according to claim 7, characterized in that, The battery pack contains 3 to 10 batteries, and the corresponding detection circuit system includes 3 to 10 detection circuits.

9. The intelligent lithium battery voltage equalization system disconnection detection system according to claim 8, characterized in that, The detection circuit includes resistors R1, R2, and R3, and transistor Q1. The collector (c) of transistor Q1 is connected to one end of resistor R3. The other end of resistor R3 and the emitter (e) of transistor Q1 are respectively connected to the two ends of a filter capacitor connected in parallel to the corresponding battery. One end of resistor R1 and one end of resistor R2 are connected to the disconnection detection signal control terminal. The other ends of resistor R1 and the other ends of resistor R2 are respectively connected to the emitter (e) and base (b) of transistor Q1.

10. The intelligent lithium battery voltage equalization system disconnection detection system according to claim 5, characterized in that, The aforementioned disconnection detection signal is a current signal.

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