Battery power supply with leakage protection function

Abstract

The present invention proposes a battery power supply with a leakage protection function, which belongs to the field of battery protection technology. A protection control module composed of a current mirror and an operational amplifier as core components is used to collect the leakage current at the power supply end of the battery power supply and perform leakage judgment. When it is determined that the battery is leaking, the switch on the power supply path of the battery power supply is disconnected to protect the battery power supply, and an alarm is issued through an alarm module. Through the design of the protection control module and the setting of the aspect ratio of the switch tube in the current mirror, the use of a large resistance current detection resistor is avoided. On the one hand, the power supply volume is reduced and the detection accuracy is improved. On the other hand, the energy dissipation and heat generation of the power supply are reduced, and the power supply efficiency of the power supply is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of battery protection, and in particular relates to a battery power supply with a leakage protection function. Background Art

[0002] Batteries have become a common power source in the industrial field. They can be used as the main power source or backup power source and are widely used in the automotive, shipbuilding, aerospace and other industries. Factors such as uneven electrolyte concentration, aging or damage of the internal structure, and overcharging can cause battery leakage, thereby affecting the use of the battery and failing to guarantee the power supply effect to the load. Therefore, it is necessary to detect the battery leakage. In the prior art, the leakage detection of batteries usually adopts the method of neutral point grounding to detect leakage current. The circuit principle is specifically referred to the attached manual. Figure 1 First, the voltage U1 across the battery B and the voltage U2 between the battery B and the ground are detected by a voltage acquisition module such as a sensor. Then, based on the Thevenin theorem, the leakage current IL between the battery and the ground is calculated according to the voltage U1, voltage U2, and the values ​​of the current detection resistors R1, R2, and R3, so as to determine whether the battery B has leakage.

[0003] The above-mentioned neutral point grounding leakage current detection method requires calculation of the voltage on the resistors R1, R2 and R3. However, the resistance values ​​of the above-mentioned resistors R1, R2 and R3 will change with the change of the circuit operating temperature, resulting in the change of the voltage on the resistors. Therefore, it is necessary to use resistors with higher resistance values ​​as the above-mentioned resistors R1, R2 and R3, which are large in size and have limited detection accuracy. In addition, the leakage current will generate energy dissipation on the above-mentioned resistors R1, R2 and R3, causing the power supply to heat up and affecting the efficiency. Summary of the invention

[0004] The purpose of the present invention is to provide a battery power supply with a leakage protection function, using a protection control module composed of a current mirror and an operational amplifier as core components to collect the leakage current of the power supply end of the battery power supply and perform leakage judgment. When it is determined that the battery is leaking, the switch on the power supply path of the battery power supply is disconnected to protect the battery power supply, and an alarm is issued through an alarm module. Through the design of the protection control module and the setting of the aspect ratio of the switch tube in the current mirror, the use of a large resistance current detection resistor is avoided, which reduces the volume of the power supply and improves the detection accuracy on the one hand, and reduces the energy dissipation and heat generation of the power supply on the other hand, thereby improving the power supply efficiency of the power supply.

[0005] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a battery power supply with leakage protection function, comprising a battery, a protection control module, a protection switch, a diode and an alarm module, the positive pole of the battery is respectively connected to the first input terminal of the protection control module and the first terminal of the protection switch, the second terminal of the protection switch is connected to the anode of the diode, and the cathode of the diode serves as the positive output terminal of the battery power supply; the negative pole of the battery is connected to the second input terminal of the protection control module and grounded, and the negative pole of the battery serves as the negative output terminal of the battery power supply; the output terminal of the protection control module is connected to the control terminal of the protection switch and the input terminal of the alarm module; the protection control module is used to control the protection switch to be disconnected when it is determined that the battery has leakage, and control the alarm module to alarm.

[0006] Furthermore, in the protection control module, a first end of the switch tube M1 is connected to the positive electrode of the battery, a second end of the switch tube M1 is connected to the first end of the switch tube M2, a control end of the switch tube M1 and a control end of the switch tube M2 are both connected to the drive signal Vdr2, a second end of the switch tube M2 is connected to the first end of the switch tube M3, a second end of the switch tube M3 is connected to the first end of the switch tube M4, a second end of the switch tube M4 is grounded, a first end of the switch tube M5 is connected to the power supply VDD2 through a resistor R1, a second end of the switch tube M5 is grounded, and a control end of the switch tube M5 is connected to the control end of the switch tube M4; a first end of the switch tube M6 is connected to the positive electrode of the battery, and a second end of the switch tube M6 is grounded. The control end of the switch tube M6 is connected to the driving signal Vdr1, the second end of the switch tube M6 is connected to the first end of the switch tube M7, the second end of the switch tube M7 is connected to the first end of the switch tube M9, the second end of the switch tube M9 is grounded, the first end of the switch tube M8 is connected to the second end of the switch tube M6, the second end of the switch tube M8 is connected to one end of the resistor R2, the other end of the resistor R2 is grounded through the resistor R6, the control end of the switch tube M8 is connected to the second end of the switch tube M7, and the control end of the switch tube M9 is connected to the control end of the switch tube M4; the positive input end of the operational amplifier AMP1 is connected to the second end of the switch tube M6, and the negative input end of the operational amplifier AMP1 is connected to the switch The output end of the operational amplifier AMP1 is connected to the control end of the switch tube M7 and the control end of the switch tube M3; the positive input end of the operational amplifier AMP2 is connected to the common point of the resistor R2 and the resistor R6, the negative input end of the operational amplifier AMP2 is connected to the second end of the switch tube M8 through the resistor R3, the output end of the operational amplifier AMP2 is connected to the control end of the switch tube M10, the first end of the switch tube M10 is connected to the negative input end of the operational amplifier AMP2, the second end of the switch tube M10 is connected to the first end of the switch tube M12, the second end of the switch tube M12 is connected to one end of the resistor R5, the other end of the resistor R5 is grounded, and the switch tube The control end of M12 is connected to the power supply VDD1, and the power supply VDD1 is also connected to the first end of the switch tube M11. The second end of the switch tube M11 is grounded. The control end of the switch tube M11 is connected to one end of the resistor R4, and the other end of the resistor R4 is grounded. One end of the resistor R4 is connected to the anode of the voltage regulator tube TVS, and the cathode of the voltage regulator tube TVS is connected to the second end of the switch tube M8; one end of the resistor R5 is also connected to the negative input end of the operational amplifier AMP3, and the positive input end of the operational amplifier AMP3 is connected to the reference voltage Vref. The output end of the operational amplifier AMP3 serves as the output end of the protection control module, and is connected to the control end of the protection switch and the input end of the alarm module.

[0007] Furthermore, the output end of the protection control module is also connected to the input end of the driving module DRV, and the output end of the driving module DRV is connected to the control end of the protection switch and the input end of the alarm module; the driving module DRV can adopt a push-pull driving circuit or a bootstrap driving circuit.

[0008] Furthermore, the aspect ratio of the switch tube M6 is greater than the aspect ratio of the switch tube M1.

[0009] Furthermore, the battery is a battery pack composed of a plurality of battery cells connected in series.

[0010] Furthermore, the driving signal Vdr1 is at a low level, and the driving signal Vdr2 is used to control the protection control module to perform leakage current detection of the battery power supply.

[0011] Furthermore, the alarm module is one of a buzzer, an alarm light or a vibrator; and the protection switch is one of a MOS tube or a triode.

[0012] The beneficial technical effects of the present invention compared with the prior art are: designing a protection control module composed of a current mirror and an operational amplifier as core components, setting the aspect ratio of the switch tube in the current mirror, avoiding the use of a large-resistance current detection resistor, reducing the size of the power supply and improving the detection accuracy, while also reducing the energy dissipation and heat generation of the power supply, and improving the power supply efficiency of the power supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. Obviously, the drawings in the following description are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0014] Figure 1 The present invention is an existing battery leakage detection circuit diagram;

[0015] Figure 2 The present invention is a battery leakage detection circuit diagram;

[0016] Figure 3 It is a structural diagram of the protection control module of the present invention. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] The following first describes the concepts involved in the present application in conjunction with the accompanying drawings. It should be noted that the following description of each concept is only to make the content of the present application easier to understand, and does not limit the scope of protection of the present application; at the same time, the embodiments and features in the embodiments of the present application can be combined with each other in the absence of conflict. The present application will be described in detail with reference to the accompanying drawings and in conjunction with the embodiments.

[0019] In conjunction with the instruction manual Figure 2 The present invention discloses a battery power supply with leakage protection function, including a battery B, a protection control module U1, a protection switch K1, a diode D1 and an alarm module. The positive electrode of the battery B is respectively connected to the first input terminal of the protection control module U1 and the first terminal of the protection switch K1, the second terminal of the protection switch K1 is connected to the anode of the diode D1, and the cathode of the diode D1 is used as the positive output terminal of the battery power supply; the negative electrode of the battery B is connected to the second input terminal of the protection control module U1 and grounded, and the negative electrode of the battery B is used as the negative output terminal of the battery power supply; the output terminal of the protection control module U1 is connected to the control terminal of the protection switch K1 and the input terminal of the alarm module; the protection control module U1 is used to control the protection switch K1 to disconnect when determining that the battery B has leakage, and control the alarm module to alarm. The battery B in the present invention can be a lead battery, a lead-acid battery or a nickel battery, and the battery B includes a battery pack composed of multiple battery cells connected in series; the alarm module can be one of a buzzer, an alarm light or a vibrator; the protection switch can be one of a MOS tube, an IGBT or a triode. In the present invention, a protection control module is used to determine whether the voltage generated by the leakage current of battery B exceeds a reference value. When the voltage exceeds the reference value, the protection switch is controlled to be disconnected to facilitate inspection and maintenance by technicians, thereby protecting battery B. At the same time, an alarm module is used to sound an alarm to indicate leakage.

[0020] In conjunction with the instruction manual Figure 3The specific topological structure of the protection control module in the present invention is as follows: the first end of the switch tube M1 is connected to the positive electrode of the battery B, the second end of the switch tube M1 is connected to the first end of the switch tube M2, the control end of the switch tube M1 and the control end of the switch tube M2 are both connected to the drive signal Vdr2, the second end of the switch tube M2 is connected to the first end of the switch tube M3, the second end of the switch tube M3 is connected to the first end of the switch tube M4, the second end of the switch tube M4 is grounded, the first end of the switch tube M5 is connected to the power supply VDD2 through the resistor R1, the second end of the switch tube M5 is grounded, and the control end of the switch tube M5 is connected to the control end of the switch tube M4; the first end of the switch tube M6 is connected to the positive electrode of the battery B, and the switch tube The control end of M6 is connected to the driving signal Vdr1, the second end of the switch tube M6 is connected to the first end of the switch tube M7, the second end of the switch tube M7 is connected to the first end of the switch tube M9, the second end of the switch tube M9 is grounded, the first end of the switch tube M8 is connected to the second end of the switch tube M6, the second end of the switch tube M8 is connected to one end of the resistor R2, the other end of the resistor R2 is grounded through the resistor R6, the control end of the switch tube M8 is connected to the second end of the switch tube M7, the control end of the switch tube M9 is connected to the control end of the switch tube M4; the positive input end of the operational amplifier AMP1 is connected to the second end of the switch tube M6, the negative input end of the operational amplifier AMP1 is connected to the second end of the switch tube M2, the operational amplifier The output end of AMP1 is connected to the control end of the switch tube M7 and the control end of the switch tube M3; the positive input end of the operational amplifier AMP2 is connected to the common point of the resistor R2 and the resistor R6, the negative input end of the operational amplifier AMP2 is connected to the second end of the switch tube M8 through the resistor R3, the output end of the operational amplifier AMP2 is connected to the control end of the switch tube M10, the first end of the switch tube M10 is connected to the negative input end of the operational amplifier AMP2, the second end of the switch tube M10 is connected to the first end of the switch tube M12, the second end of the switch tube M12 is connected to one end of the resistor R5, the other end of the resistor R5 is grounded, the control end of the switch tube M12 is connected to the power supply VDD1, and the power supply VDD1 is also connected The first end of the switch tube M11 and the second end of the switch tube M11 are grounded, the control end of the switch tube M11 is connected to one end of the resistor R4, the other end of the resistor R4 is grounded, one end of the resistor R4 is connected to the anode of the voltage regulator tube TVS, and the cathode of the voltage regulator tube TVS is connected to the second end of the switch tube M8; one end of the resistor R5 is also connected to the negative input end of the operational amplifier AMP3, the positive input end of the operational amplifier AMP3 is connected to the reference voltage Vref, and the reference voltage Vref can be determined according to the factory parameters and service life of the battery B. The output end of the operational amplifier AMP3 is used as the output end of the entire protection control module, and is connected to the control end of the protection switch K1 and the input end of the alarm module. The drive signal Vdr1 is low level, and the drive signal Vdr2 is used to control the protection control module to perform leakage current detection of the battery power supply, that is, when the leakage current detection of the battery power supply is required, the drive signal Vdr2 is controlled to be low level to turn on the switch tubes M1 and M2.

[0021] When the leakage current of the battery power supply is detected, if the battery B leaks, the leakage current IL will flow through the branch where the switch tube M1 is located. The mirror effect of the switch tubes M1 and M6 causes the current Is to be induced in the branch where the switch tube M6 is located. The clamping effect of the transport amplifier AMP1 makes the branch current I1 smaller, so the detection current Isense is approximately the same as the branch current Is of the switch tube M6. By setting the size of the switch tubes M1 and M6, the ratio of Is and IL can be adjusted so that Is is greater than the leakage current IL of the battery. In this way, by cooperating with the current mirror and the operational amplifier, the width-to-height ratio of the switch tubes M1 and M6 can be set to appropriately amplify the leakage current of the battery, so that the use of large-resistance resistors can be avoided. On the one hand, the power supply volume is reduced and the detection accuracy is improved. On the other hand, the energy dissipation and heat generation of the power supply are reduced, and the power supply efficiency of the power supply is improved.

[0022] Specifically, the aspect ratio of the switch tube M6 needs to be set greater than that of the switch tube M1, preferably the aspect ratio of the switch tube M6 is more than fifty times the aspect ratio of the switch tube M1. It can be understood that adjusting the aspect ratio of the switch tubes M6 and M1 can change the detection range of the battery leakage current.

[0023] The function of the operational amplifier AMP2 is to further amplify the voltage on the detection resistor R2 as the detection voltage corresponding to the leakage current of the battery B. Setting the switch tubes M10, M11 and M12 can improve the withstand voltage level of the entire circuit and play a protective role in the power supply circuit.

[0024] Finally, the detection voltage VSEN represents the leakage degree of the battery. The detection voltage VSEN is calculated as follows: VSEN = VX × (R5 / R3) × K, where VX represents the Figure 3 The voltage of the node X, R5 represents the resistance value of the resistor R5, R3 represents the resistance value of the resistor R3, and K represents the amplification factor of the operational amplifier AMP2. The detection voltage VSEN is compared with the reference voltage Vref, and the comparison result is used to determine whether the battery is leaking.

[0025] As another embodiment of the present invention, further in combination with the attached Figure 3 The output end of the protection control module of the present invention can also be connected to the input end of the driving module DRV, and the output end of the driving module DRV is connected to the control end of the protection switch and the input end of the alarm module. The driving module DRV in the present invention can use a push-pull driving circuit or a bootstrap driving circuit to drive the protection switch K1, speed up the disconnection speed of the protection switch K1, and protect the battery in time.

[0026] The embodiments and / or implementation methods described above are only used to illustrate the preferred embodiments and / or implementation methods for realizing the technology of the present invention, and are not intended to limit the implementation methods of the technology of the present invention in any form. Any technical personnel in this field may make slight changes or modifications to other equivalent embodiments without departing from the scope of the technical means disclosed in the content of the present invention, but they should still be regarded as technologies or embodiments that are essentially the same as the present invention.

[0027] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and its core ideas of this application. The above is only the preferred implementation method of this application. It should be pointed out that due to the limitations of textual expression and the objective existence of infinite specific structures, ordinary technicians in this technical field can make several improvements, modifications or changes without departing from the principles of this application, and can also combine the above technical features in an appropriate manner; these improvements, modifications, changes or combinations, or the direct application of the concept and technical solution of the invention to other occasions without improvement, should be regarded as the scope of protection of this application.

Claims

1. A battery power supply with leakage protection function, characterized in that: It includes a battery, a protection control module, a protection switch, a diode and an alarm module, wherein the positive electrode of the battery is respectively connected to the first input terminal of the protection control module and the first terminal of the protection switch, the second terminal of the protection switch is connected to the anode of the diode, and the cathode of the diode serves as the positive output terminal of the battery power supply; the negative electrode of the battery is connected to the second input terminal of the protection control module and is grounded, and the negative electrode of the battery serves as the negative output terminal of the battery power supply; the output terminal of the protection control module is connected to the control terminal of the protection switch and the input terminal of the alarm module; the protection control module is used to control the protection switch to disconnect when determining that the battery has leakage, and control the alarm module to alarm; The first end of the switch tube M1 in the protection control module is connected to the positive electrode of the battery, the second end of the switch tube M1 is connected to the first end of the switch tube M2, the control end of the switch tube M1 and the control end of the switch tube M2 are both connected to the drive signal Vdr2, the second end of the switch tube M2 is connected to the first end of the switch tube M3, the second end of the switch tube M3 is connected to the first end of the switch tube M4, the second end of the switch tube M4 is grounded, the first end of the switch tube M5 is connected to the power supply VDD2 through the resistor R1, the second end of the switch tube M5 is grounded, and the control end of the switch tube M5 is connected to the control end of the switch tube M4; A first end of the switch tube M6 is connected to the positive electrode of the battery, a control end of the switch tube M6 is connected to the drive signal Vdr1, a second end of the switch tube M6 is connected to a first end of the switch tube M7, a second end of the switch tube M7 is connected to a first end of the switch tube M9, a second end of the switch tube M9 is grounded, a first end of the switch tube M8 is connected to a second end of the switch tube M6, a second end of the switch tube M8 is connected to one end of the resistor R2, the other end of the resistor R2 is grounded through the resistor R6, a control end of the switch tube M8 is connected to the second end of the switch tube M7, and a control end of the switch tube M9 is connected to a control end of the switch tube M4; The positive input terminal of the operational amplifier AMP1 is connected to the second terminal of the switch tube M6, the negative input terminal of the operational amplifier AMP1 is connected to the second terminal of the switch tube M2, and the output terminal of the operational amplifier AMP1 is connected to the control terminal of the switch tube M7 and the control terminal of the switch tube M3; The positive input terminal of the operational amplifier AMP2 is connected to the common point of the resistor R2 and the resistor R6, the negative input terminal of the operational amplifier AMP2 is connected to the second end of the switch tube M8 through the resistor R3, the output terminal of the operational amplifier AMP2 is connected to the control terminal of the switch tube M10, the first end of the switch tube M10 is connected to the negative input terminal of the operational amplifier AMP2, the second end of the switch tube M10 is connected to the first end of the switch tube M12, the second end of the switch tube M12 is connected to one end of the resistor R5, the other end of the resistor R5 is grounded, the control end of the switch tube M12 is connected to the power supply VDD1, the power supply VDD1 is also connected to the first end of the switch tube M11, the second end of the switch tube M11 is grounded, the control end of the switch tube M11 is connected to one end of the resistor R4, the other end of the resistor R4 is grounded, one end of the resistor R4 is connected to the anode of the voltage regulator tube TVS, and the cathode of the voltage regulator tube TVS is connected to the second end of the switch tube M8; One end of the resistor R5 is also connected to the negative input end of the operational amplifier AMP3, the positive input end of the operational amplifier AMP3 is connected to the reference voltage Vref, and the output end of the operational amplifier AMP3 serves as the output end of the protection control module, connecting the control end of the protection switch and the input end of the alarm module.

2. The battery power supply with leakage protection function as claimed in claim 1, characterized in that: The output end of the protection control module is also connected to the input end of the driving module DRV, and the output end of the driving module DRV is connected to the control end of the protection switch and the input end of the alarm module; the driving module DRV adopts a push-pull driving circuit or a bootstrap driving circuit.

3. The battery power supply with leakage protection function as claimed in claim 1, characterized in that: The aspect ratio of the switch tube M6 is greater than that of the switch tube M1 .

4. The battery power supply with leakage protection function as claimed in claim 1, characterized in that: The driving signal Vdr1 is at a low level, and the driving signal Vdr2 is used to control the protection control module to perform leakage current detection of the battery power supply.

5. The battery power supply with leakage protection function as claimed in claim 1, characterized in that: The storage battery is a storage battery pack composed of a plurality of battery cells connected in series.

6. The battery power supply with leakage protection function as claimed in claim 1, characterized in that: The alarm module is one of a buzzer, an alarm light or a vibrator.

7. The battery power supply with leakage protection function as claimed in claim 1, characterized in that: The protection switch is a MOS tube or a triode.

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