Battery system electric leakage detection system

Abstract

The utility model provides an electric leakage detection system of a battery system. The electric leakage detection system comprises a normal circuit module, a main loop electric leakage induction loop, a PWM pulse emission module and an electric leakage detection module. The normal circuit module is connected with the battery system, the main loop electric leakage induction loop and the PWM pulse transmitting module; the normal circuit module is provided with a normal voltage node, the main loop electric leakage induction loop comprises a conductive material wrapping the insulating outer layer of the main loop, the main loop electric leakage induction loop is provided with an induction voltage node used for detecting whether electric leakage or short circuit occurs in the main loop, and the electric leakage detection module is provided with a detection node. According to the utility model, the normal voltage node is arranged in the normal circuit module, the induced voltage node is arranged in the main circuit leakage induction circuit, and the detection node is arranged in the leakage detection module, so that various states of leakage of the battery system can be detected through the waveform of the voltage of each node, and complicated control logic is not needed; the battery system electric leakage detection cost can be reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of battery system leakage detection, in particular to a battery system leakage detection system. Background Art

[0002] In recent years, new energy four-wheeled and two-wheeled vehicles have developed rapidly, and lithium batteries of different voltage platforms have become popular. In order to solve the problem of fast charging, the voltage platform has gradually increased from 380V to 800V. However, the higher the voltage, the higher the risk factor, especially when abnormal conditions such as leakage and short circuit occur, the harm is extremely great; circuit leakage or short circuit will cause direct harm to the human body and is prone to fire. At present, the use scenarios of electric vehicles are diverse and long-term. The circuit is prone to leakage, short circuit or open circuit caused by friction, vibration and aging. At present, the industry's technical detection of short circuit or open circuit is relatively mature, but leakage detection technology is relatively rare, mainly affected by high cost, and the probability of occurrence is relatively low. For this reason, manufacturers rarely cite relevant technologies for leakage. Therefore, the application of low-cost battery main circuit leakage detection is a key issue that needs to be solved in the industry.

[0003] Electric vehicle battery main circuit leakage is an important factor affecting safe driving. Electric vehicle battery main circuit leakage may be caused by a variety of reasons, such as line aging, poor connection, collision causing battery short circuit, etc. To prevent leakage, we currently need to take the following measures: First, choose electric vehicles with reliable quality, and try to avoid choosing low-quality or second-hand electric vehicles; second, regularly conduct comprehensive inspections of electric vehicles, especially the line connection parts, to ensure that the connections between the components are stable. The above mentioned is that it is impossible to self-detect and manage through the electric vehicle battery system:

[0004] Patent 202111354777.4 discloses a leakage detection method and a leakage detection device: after the pre-charging is completed and before the vehicle is in a drivable state, the controller receives a leakage detection instruction and the high-voltage module to be tested for leakage has no faults, and the high-voltage module to be tested for leakage is controlled to be energized to form a leakage detection circuit with the leakage detection module to perform leakage detection on the high-voltage module to be tested for leakage, wherein the duration of the energization of the high-voltage module to be tested for leakage is greater than the detection time of the leakage detection sensor in the leakage detection module; the leakage detection speed is slow, the control process is complex, the cost is high, and the applicability is low. Utility Model Content

[0005] In order to overcome the above technical defects, the utility model provides a battery system leakage detection system with a simple structure.

[0006] In order to solve the above problems, the present invention is implemented according to the following technical solutions:

[0007] A battery system leakage detection system, wherein the battery system is provided with a main circuit, including: a normal circuit module, a main circuit leakage induction circuit, a PWM pulse transmission module and a leakage detection module;

[0008] The normal circuit module is connected to the battery system, the main circuit, and the PWM pulse transmission module;

[0009] The normal circuit module is provided with a normal voltage node, the main circuit leakage induction circuit includes: a conductive material wrapped in the outer insulating layer of the main circuit, the main circuit leakage induction circuit is provided with an induction voltage node for detecting whether the main circuit is leaking or short-circuited, and the leakage detection module is provided with a detection node.

[0010] As a further improvement of the present invention, the normal circuit module includes: a first resistor, a second resistor;

[0011] The positive electrode of the battery system is connected to the negative electrode of the battery system through the first resistor and the second resistor;

[0012] A connection point between the first resistor and the second resistor is grounded, and a connection point between the first resistor and the second resistor is the normal voltage node.

[0013] As a further improvement of the present invention, the leakage detection module includes: a third resistor, a fourth resistor, a fifth resistor, a first voltage regulator tube, a second voltage regulator tube and an analog / digital converter;

[0014] The main circuit is connected to the analog / digital converter through the third resistor and the fourth resistor;

[0015] The main circuit is grounded through the third resistor and the fifth resistor;

[0016] The third resistor is connected to the positive electrode of the first voltage-stabilizing diode and the negative electrode of the second voltage-stabilizing diode respectively, the negative electrode of the first voltage-stabilizing diode is connected to the analog / digital converter, and the positive electrode of the second voltage-stabilizing diode is grounded;

[0017] The connection point between the positive electrode of the first voltage regulator tube and the negative electrode of the second voltage regulator tube is a detection node.

[0018] As a further improvement of the present invention, the main circuit includes: a sixth resistor, a seventh resistor, and an eighth resistor;

[0019] The PWM pulse transmitting module is connected to the positive electrode of the battery system through the seventh resistor and the sixth resistor;

[0020] The negative electrode of the battery system is connected to the third resistor through the eighth resistor;

[0021] The positive electrode of the battery system is connected to the negative electrode of the battery system through the sixth resistor and the eighth resistor;

[0022] A connection point between the sixth resistor and the eighth resistor is the induced voltage node.

[0023] As a further improvement of the present invention, the resistance values ​​of the first resistor, the second resistor, the sixth resistor, and the eighth resistor are equal.

[0024] As a further improvement of the present invention, the resistance values ​​of the third resistor, the fourth resistor, the fifth resistor, and the seventh resistor are equal.

[0025] As a further improvement of the present invention, the normal circuit module is connected to the main loop leakage sensing circuit via a switch.

[0026] Compared with the prior art, the battery system leakage detection system provided by the present invention has the following beneficial effects: by providing a normal circuit module, a main circuit, a main circuit leakage induction circuit, a PWM pulse transmission module and a leakage detection module, at the same time, a normal voltage node is provided in the normal circuit module, an induction voltage node is provided in the main circuit leakage induction circuit, and a detection node is provided in the leakage detection module. Various leakage states of the battery system can be detected through the waveforms of the voltages at each node. The structure is simple, and there is no need to adopt complex control logic, which can greatly reduce the cost of detecting battery system leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a framework diagram of the battery system leakage detection system of the present utility model;

[0028] Figure 2 This is a circuit diagram of the battery leakage detection system of the present utility model;

[0029] Figure 3 This is the equivalent circuit diagram of the battery leakage detection system of the present utility model;

[0030] Figure 4 This is an equivalent circuit diagram of the battery leakage detection system of the present invention when the positive electrode leaks;

[0031] Figure 5 This is an equivalent circuit diagram of the battery leakage detection system of the present invention when the positive electrode is short-circuited;

[0032] Figure 6 This is an equivalent circuit diagram of the battery leakage detection system of the present invention when the negative electrode is leaking;

[0033] Figure 7 This is an equivalent circuit diagram of the battery leakage detection system of the present invention when the negative electrode is short-circuited;

[0034] Figure 8 This is an equivalent circuit diagram of the battery leakage detection system of the present invention when the induction line is broken;

[0035] Figure 9 This is a waveform-fault comparison diagram of the battery leakage detection system described in the present invention.

[0036] Explanation of the accompanying drawings: 1. Normal circuit module; 2. Main circuit; 3. PWM pulse transmission module; 4. Leakage detection module; 5. Main circuit leakage induction circuit.

[0037] 100. Battery system. DETAILED DESCRIPTION

[0038] The preferred embodiment of the present invention will be described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiment described herein is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0039] This embodiment discloses a battery system leakage detection system, the battery system 100 is provided with a main circuit 2, such as Figure 1 As shown, it includes: a normal circuit module 1, a PWM pulse transmitting module 3 and a leakage detection module 4; the normal circuit module 1 is connected to the battery system, the main circuit 2, and the PWM pulse transmitting module 3; the normal circuit module 1 is provided with a normal voltage node, and the main circuit leakage induction circuit 5 includes: a conductive material wrapped in the insulating outer layer of the main circuit 2, the main circuit leakage induction circuit 5 is provided with an induction voltage node for detecting whether the main circuit 2 is leaking or short-circuited, and the leakage detection module 4 is provided with a detection node.

[0040] like Figure 2 As shown, the normal circuit module 1 includes: a first resistor R1 and a second resistor R2; the positive electrode of the battery system is connected to the negative electrode of the battery system through the first resistor R1 and the second resistor R2; the connection point of the first resistor R1 and the second resistor R2 is grounded, and the connection point of the first resistor R1 and the second resistor R2 is a normal voltage node.

[0041] The leakage detection module 4 includes: a third resistor R3, a fourth resistor R4, a fifth resistor R5, a first voltage-stabilizing diode D1, a second voltage-stabilizing diode D2, and an analog-to-digital converter (ADC). The main circuit 2 is connected to the analog-to-digital converter (ADC) via the third and fourth resistors R3 and R4. The main circuit 2 is grounded via the third and fifth resistors R3 and R5. The third resistor R3 is connected to the positive electrode of the first voltage-stabilizing diode D1 and the negative electrode of the second voltage-stabilizing diode D2, respectively. The negative electrode of the first voltage-stabilizing diode D1 is connected to the analog-to-digital converter (ADC), and the positive electrode of the second voltage-stabilizing diode D2 is grounded. The analog-to-digital converter (ADC) is used to convert analog voltage signals into digital voltage signals.

[0042] The main circuit 2 includes: a sixth resistor R6, a seventh resistor R7, and an eighth resistor R8; the PWM pulse transmitting module 3 is connected to the positive electrode of the battery system through the seventh resistor R7 and the sixth resistor R6; the negative electrode of the battery system is connected to the third resistor R3 through the eighth resistor R8; the positive electrode of the battery system is connected to the negative electrode of the battery system through the sixth resistor R6 and the eighth resistor R8; the connection point between the sixth resistor R6 and the eighth resistor R8 is an induced voltage node.

[0043] The resistance values ​​of the first resistor R1 , the second resistor R2 , the sixth resistor R6 , and the eighth resistor R8 are equal.

[0044] The resistance values ​​of the third resistor R3 , the fourth resistor R4 , the fifth resistor R5 , and the seventh resistor R7 are equal.

[0045] The normal circuit module 1 is connected to the main loop leakage induction circuit through the switch K.

[0046] The utility model is provided with a normal circuit module, a main circuit, a main circuit leakage induction circuit, a PWM pulse transmission module and a leakage detection module. At the same time, a normal voltage node is provided in the normal circuit module, an induction voltage node is provided in the main circuit leakage induction circuit, and a detection node is provided in the leakage detection module. Various leakage states of the battery system can be detected through the waveforms of the voltages at each node. The structure is simple, and there is no need to adopt complex control logic, which can greatly reduce the detection cost of battery system leakage.

[0047] Next, the present invention is explained in conjunction with the specific implementation process as follows:

[0048] Before performing leakage detection, switch S1 must be in the closed state.

[0049] It should be noted that, since the resistance values ​​of the first resistor R1, the second resistor R2, the sixth resistor R6, and the eighth resistor R8 are equal, and the resistance values ​​of the third resistor R3, the fourth resistor R4, the fifth resistor R5, and the seventh resistor R7 are equal, in the following text, for the convenience of description, the first resistor R1, the second resistor R2, the sixth resistor R6, and the eighth resistor R8 are equal. Figures 2 to 8 The third resistor R3, the fourth resistor R4, the fifth resistor R5, and the seventh resistor R7 are replaced by R2', and the line in the main circuit leakage induction loop 5 is equivalent to the resistor R3'; the theoretical resistance of the leakage induction line is close to 0Ω, which is equivalent to R4'.

[0050] like Figure 3As shown, in the absence of PWM pulse influence, the induced voltage node voltage U2 in the main circuit leakage induction loop 5 is the same as the normal voltage node voltage U0, and the difference between the two is 0; when the PWM emitted by the PWM pulse transmitting module 3 is a high-level voltage U1, the equivalent resistance between the leakage detection module 4U1 to U3 is: (R2'+R2') / / R2'=2 / 3R2', at this time, the voltage of the detection node U3 is: 3(U1-U0) / 5; when the PWM is a low-level voltage, the equivalent resistance between the leakage detection module 4U3 to U0 is: (R2'+R2') / / R2'=2 / 3R2', at this time, the voltage of the detection node U3 is: 2(U1-U0) / 5, according to the high and low levels of PWM, the induced voltage node voltage U3 is 2(U1-U0) / 5 at low level and 3(U1-U0) / 5 at high level, and the induced voltage node voltage U3 is consistent with the graph of the pulse width PWM pulse transmitting module 3, as shown Figure 9 The normal curve value in the working mode detection graph is a midline upper and lower pulse of (U1-U0) / 2; that is, when the induced voltage node voltage U3 pulses up and down on the midline, it is determined that there is no leakage.

[0051] like Figure 4 As shown in the circuit diagram, the positive electrode of the battery system is equivalent to a leakage resistor R3' in the main circuit leakage induction circuit 5. At this time, in the absence of PWM pulse influence, the induced voltage node voltage U2 of the main circuit leakage induction circuit 5 is greater than the normal voltage node voltage U0, and the difference between the two is (U2-U0)>0; when the PWM is a high-level voltage U1, the equivalent resistance between the leakage detection module 4U1 to U3 is (R2'+R2') / / R2'=2 / 3R2', and the detection node voltage U3 is close to 3(U1-U0) / 5+2(U2-U0) / 3; when the PWM is low When the voltage is level, the equivalent resistance between the leakage detection module 4U3 and U0 is (R2'+R2') / / R2'=2 / 3R2'. At this time, the voltage of the induced voltage node U3 is 2(U1-U0) / 5+2(U2-U0) / 3. According to the high and low levels of PWM, the induced voltage node U3 is: the low level is 2(U1-U0) / 5+2(U2-U0) / 3, and the high level is 3(U1-U0) / 5+2(U2-U0) / 3. That is to say, the pulse width of the induced voltage node U3 is consistent with the graph of the PWM pulse transmitting module 3, as shown in FIG. Figure 9 The leakage curve of the induced voltage node in the working mode detection graph deviates from (U1-U0) / 2 and pulses upward; that is, when the induced voltage node voltage U3 is on the center line, it is determined that the positive electrode of the battery system is leaking.

[0052] like Figure 5As shown in the circuit diagram, the positive electrode of the battery system is completely short-circuited to the main circuit leakage induction loop 5. At this time, without the influence of PWM pulses, the voltage U2 of the induction voltage node of the main circuit leakage induction loop 5 is greater than the voltage U0 of the normal voltage node, and the difference is (U2 - U0) >> U1. Since (U2 - U0) >> U1, at this time, the PWM pulse emission module 3 is ineffective, and the voltage at the induction voltage node U3 is much greater than U1. The voltage of the induction voltage node U3 will form a straight-line graph, as Figure 9 The short-circuit curve graph straight-line graph in the working mode detection graph; that is, when the voltage U3 of the induction voltage node is in a straight line and is located on the center line, it is judged that the positive electrode of the battery system is short-circuited.

[0053] As Figure 6 As shown in the circuit diagram, at this time, the negative electrode of the battery system is equivalent to a leakage resistance R3' in the main circuit leakage induction loop 5. At this time, without the influence of PWM pulses, the voltage U2 of the induction voltage node of the main circuit leakage induction loop 5 is less than the normal voltage node voltage U0, and the difference between the two is (U2 - U0) < 0. When PWM is the high-level voltage U1, the equivalent resistance between U1 and U3 of the leakage detection module 4 is (R2' + R2') / / R2' = 2 / 3R2'. At this time, the detected node voltage U3 is close to 3(U1 - U0) / 5 - 2(U2 - U0) / 3. When PWM is the low-level voltage, the equivalent resistance between U3 and U0 of the leakage detection module 4 is (R2' + R2') / / R2' = 2 / 3R2'. At this time, the voltage of the detected node voltage U3 is 2(U1 - U0) / 5 - 2(U0 - U2) / 3. According to the induction voltage node voltage U3 formed by the high and low levels of PWM like this: low level 2(U1 - U0) / 5 - 2(U0 - U2) / 3, high level 3(U1 - U0) / 5 - 2(U0 - U2) / 3, the graph of the induction voltage node voltage U3 is the same as that of the PWM pulse emission module 3, as Figure 9 The leakage curve graph in the working mode detection graph deviates from (U1 - U0) / 2 downward with up and down pulses; that is, when the voltage U3 of the detected node is located below the center line, it is judged that the negative electrode of the battery system is leaking.

[0054] As Figure 7 As shown in the circuit diagram, the negative electrode of the battery system is completely short-circuited to the induction loop. At this time, without the influence of PWM pulses, the voltage U2 of the induction voltage node of the main circuit leakage induction loop 5 is less than the voltage U0 of the normal voltage node, and the difference is (U2 - U0) << U1. Since (U2 - U0) << U1, at this time, the PWM pulse emission module 3 is ineffective, and the voltage at the induction voltage node U3 is much less than U0. The voltage of the induction voltage node U3 will form a straight-line graph, as Figure 9 The short-circuit curve graph straight-line graph in the working mode detection graph; that is, when the voltage U3 of the induction voltage node is in a straight line and is located below the center line, it is judged that the negative electrode of the battery system is short-circuited.

[0055] like Figure 8 As shown in the circuit diagram, when there is no PWM pulse influence, the leakage detection module 4 is an independent circuit and is not affected by the outside world. The voltage of the induced voltage node U3 is equal to (U1-U0) / 2, which will form a straight line graph, as shown in FIG. Figure 9 The curve graph (U1-U0) / 2 in the working mode detection graph is a straight line graph. That is, when the induction voltage node voltage U3 is straight and located at the center line, it is determined that the induction line of the battery system is broken.

[0056] pass Figure 9 The voltage waveforms shown in Table 1 can be used to quickly determine the fault point of the battery system 100 .

[0057] Table 1 Working mode

[0058] Positive state Negative state Induction line loop Test results normal normal normal Normal median pulse leakage normal normal Deviation from the median upward pulse Short Circuit normal normal Constant pressure fixed value output normal leakage normal Deviation from the median downward pulse normal Short Circuit normal Constant pressure fixed value output — — Short Circuit Output constant median

[0059] The utility model can directly obtain the specific leakage situation of the battery system through the voltage waveform of each node, without the need for complex control of the battery system, and can greatly improve the speed and difficulty of detection.

[0060] The above is only the preferred utility model of this application and is not intended to limit this application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application should be included in the scope of protection of this application.

Claims

1. A battery system leakage detection system, wherein the battery system is provided with a main circuit, characterized in that: include: Normal circuit module, main circuit leakage induction circuit, PWM pulse transmission module and leakage detection module; The normal circuit module is connected to the battery system, the main circuit, and the PWM pulse transmission module; The normal circuit module is provided with a normal voltage node, the main circuit leakage induction circuit includes: a conductive material wrapped in the outer insulating layer of the main circuit, the main circuit leakage induction circuit is provided with an induction voltage node for detecting whether the main circuit is leaking or short-circuited, and the leakage detection module is provided with a detection node.

2. The battery system leakage detection system according to claim 1, characterized in that: The normal circuit module includes: a first resistor and a second resistor; The positive electrode of the battery system is connected to the negative electrode of the battery system through the first resistor and the second resistor; A connection point between the first resistor and the second resistor is grounded, and a connection point between the first resistor and the second resistor is the normal voltage node.

3. The battery system leakage detection system according to claim 2, characterized in that: The leakage detection module includes: a third resistor, a fourth resistor, a fifth resistor, a first voltage regulator tube, a second voltage regulator tube and an analog / digital converter; The main circuit is connected to the analog / digital converter through the third resistor and the fourth resistor; The main circuit is grounded through the third resistor and the fifth resistor; The third resistor is connected to the positive electrode of the first voltage-stabilizing diode and the negative electrode of the second voltage-stabilizing diode respectively, the negative electrode of the first voltage-stabilizing diode is connected to the analog / digital converter, and the positive electrode of the second voltage-stabilizing diode is grounded; The connection point between the positive electrode of the first voltage regulator tube and the negative electrode of the second voltage regulator tube is a detection node.

4. The battery system leakage detection system according to claim 3, characterized in that: The main circuit includes: a sixth resistor, a seventh resistor, and an eighth resistor; The PWM pulse transmitting module is connected to the positive electrode of the battery system through the seventh resistor and the sixth resistor; The negative electrode of the battery system is connected to the third resistor through the eighth resistor; The positive electrode of the battery system is connected to the negative electrode of the battery system through the sixth resistor and the eighth resistor; A connection point between the sixth resistor and the eighth resistor is the induced voltage node.

5. The battery system leakage detection system according to claim 4, characterized in that: The resistance values ​​of the first resistor, the second resistor, the sixth resistor, and the eighth resistor are equal.

6. The battery system leakage detection system according to claim 4, characterized in that: The resistance values ​​of the third resistor, the fourth resistor, the fifth resistor, and the seventh resistor are equal.

7. The battery system leakage detection system according to claim 4, characterized in that: The normal circuit module is connected to the main loop leakage induction circuit through a switch.

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